Merge pull request #29501 from vespa-engine/mpolden/cli-cleanup

CLI package cleanup

92 files changed, 401 insertions, 405 deletions

diff --git a/client/go/internal/admin/clusterstate/cluster_state.go b/client/go/internal/admin/clusterstate/cluster_state.go
index 52f7c2181b4..fe6c6c1a4d2 100644
--- a/client/go/internal/admin/clusterstate/cluster_state.go
+++ b/client/go/internal/admin/clusterstate/cluster_state.go
@@ -11,7 +11,7 @@ import (
 	"strings"
 
 	"github.com/vespa-engine/vespa/client/go/internal/admin/trace"
-	"github.com/vespa-engine/vespa/client/go/internal/util"
+	"github.com/vespa-engine/vespa/client/go/internal/osutil"
 )
 
 // common struct used various places in the clustercontroller REST api:
@@ -117,6 +117,6 @@ func (model *VespaModelConfig) getClusterState(cluster string) (*ClusterState, *
 		return &parsedJson, &cc
 	}
 	// no success:
-	util.JustExitMsg(fmt.Sprint(errs))
+	osutil.ExitMsg(fmt.Sprint(errs))
 	panic("unreachable")
 }
diff --git a/client/go/internal/admin/clusterstate/detect_model.go b/client/go/internal/admin/clusterstate/detect_model.go
index 0f261526145..db2e167ea6a 100644
--- a/client/go/internal/admin/clusterstate/detect_model.go
+++ b/client/go/internal/admin/clusterstate/detect_model.go
@@ -9,7 +9,7 @@ import (
 	"strings"
 
 	"github.com/vespa-engine/vespa/client/go/internal/admin/trace"
-	"github.com/vespa-engine/vespa/client/go/internal/util"
+	"github.com/vespa-engine/vespa/client/go/internal/osutil"
 	"github.com/vespa-engine/vespa/client/go/internal/vespa"
 )
 
@@ -17,11 +17,11 @@ func getConfigServerHosts(s string) []string {
 	if s != "" {
 		return []string{s}
 	}
-	backticks := util.BackTicksForwardStderr
+	backticks := osutil.BackTicksForwardStderr
 	got, err := backticks.Run(vespa.FindHome()+"/bin/vespa-print-default", "configservers")
 	res := strings.Fields(got)
 	if err != nil || len(res) < 1 {
-		util.JustExitMsg("bad configservers: " + got)
+		osutil.ExitMsg("bad configservers: " + got)
 	}
 	trace.Debug("found", len(res), "configservers:", res)
 	return res
@@ -31,13 +31,13 @@ func getConfigServerPort(i int) int {
 	if i > 0 {
 		return i
 	}
-	backticks := util.BackTicksForwardStderr
+	backticks := osutil.BackTicksForwardStderr
 	got, err := backticks.Run(vespa.FindHome()+"/bin/vespa-print-default", "configserver_rpc_port")
 	if err == nil {
 		i, err = strconv.Atoi(strings.TrimSpace(got))
 	}
 	if err != nil || i < 1 {
-		util.JustExitMsg("bad configserver_rpc_port: " + got)
+		osutil.ExitMsg("bad configserver_rpc_port: " + got)
 	}
 	trace.Debug("found configservers rpc port:", i)
 	return i
@@ -55,13 +55,13 @@ func detectModel(opts *Options) *VespaModelConfig {
 			"-p", strconv.Itoa(cfgPort),
 			"-s", cfgHost,
 		}
-		backticks := util.BackTicksForwardStderr
+		backticks := osutil.BackTicksForwardStderr
 		data, err := backticks.Run(vespa.FindHome()+"/bin/vespa-get-config", args...)
 		parsed := parseModelConfig(data)
 		if err == nil && parsed != nil {
 			return parsed
 		}
 	}
-	util.JustExitMsg("could not get model config")
+	osutil.ExitMsg("could not get model config")
 	panic("unreachable")
 }
diff --git a/client/go/internal/admin/clusterstate/set_node_state.go b/client/go/internal/admin/clusterstate/set_node_state.go
index a838b43503f..023d3ed71c8 100644
--- a/client/go/internal/admin/clusterstate/set_node_state.go
+++ b/client/go/internal/admin/clusterstate/set_node_state.go
@@ -16,7 +16,7 @@ import (
 	"github.com/vespa-engine/vespa/client/go/internal/admin/envvars"
 	"github.com/vespa-engine/vespa/client/go/internal/admin/trace"
 	"github.com/vespa-engine/vespa/client/go/internal/build"
-	"github.com/vespa-engine/vespa/client/go/internal/util"
+	"github.com/vespa-engine/vespa/client/go/internal/osutil"
 )
 
 const (
@@ -80,7 +80,7 @@ func runSetNodeState(opts *Options, args []string) {
 	}
 	wanted, err := knownState(args[0])
 	if err != nil {
-		util.JustExitWith(err)
+		osutil.ExitErr(err)
 	}
 	reason := ""
 	if len(args) > 1 {
@@ -138,7 +138,7 @@ func (cc *ClusterControllerSpec) setNodeUserState(s serviceSpec, wanted KnownSta
 	}
 	jsonBytes, err := json.Marshal(request)
 	if err != nil {
-		util.JustExitWith(err)
+		osutil.ExitErr(err)
 	}
 	url := fmt.Sprintf("http://%s:%d/cluster/v2/%s/%s/%d",
 		cc.host, cc.port,
diff --git a/client/go/internal/admin/deploy/cmd.go b/client/go/internal/admin/deploy/cmd.go
index 955ae93f859..f2edf3c7450 100644
--- a/client/go/internal/admin/deploy/cmd.go
+++ b/client/go/internal/admin/deploy/cmd.go
@@ -11,7 +11,7 @@ import (
 	"github.com/spf13/cobra"
 	"github.com/vespa-engine/vespa/client/go/internal/admin/trace"
 	"github.com/vespa-engine/vespa/client/go/internal/build"
-	"github.com/vespa-engine/vespa/client/go/internal/util"
+	"github.com/vespa-engine/vespa/client/go/internal/osutil"
 	"github.com/vespa-engine/vespa/client/go/internal/vespa"
 )
 
@@ -24,7 +24,7 @@ func NewDeployCmd() *cobra.Command {
 		curOptions Options
 	)
 	if err := vespa.LoadDefaultEnv(); err != nil {
-		util.JustExitWith(err)
+		osutil.ExitErr(err)
 	}
 	cobra.EnableCommandSorting = false
 	cmd := &cobra.Command{
diff --git a/client/go/internal/admin/deploy/curl.go b/client/go/internal/admin/deploy/curl.go
index 0ce1305226f..accd16b06f5 100644
--- a/client/go/internal/admin/deploy/curl.go
+++ b/client/go/internal/admin/deploy/curl.go
@@ -14,7 +14,7 @@ import (
 
 	"github.com/vespa-engine/vespa/client/go/internal/admin/trace"
 	"github.com/vespa-engine/vespa/client/go/internal/curl"
-	"github.com/vespa-engine/vespa/client/go/internal/util"
+	"github.com/vespa-engine/vespa/client/go/internal/osutil"
 	"github.com/vespa-engine/vespa/client/go/internal/vespa"
 )
 
@@ -60,20 +60,20 @@ func urlWithoutQuery(url string) string {
 func newCurlCommand(url string, args []string) *curl.Command {
 	tls, err := vespa.LoadTlsConfig()
 	if err != nil {
-		util.JustExitWith(err)
+		osutil.ExitErr(err)
 	}
 	if tls != nil && strings.HasPrefix(url, "http:") {
 		url = "https:" + url[5:]
 	}
 	cmd, err := curl.RawArgs(url, args...)
 	if err != nil {
-		util.JustExitWith(err)
+		osutil.ExitErr(err)
 	}
 	if tls != nil {
 		if tls.DisableHostnameValidation {
 			cmd, err = curl.RawArgs(url, append(args, "--insecure")...)
 			if err != nil {
-				util.JustExitWith(err)
+				osutil.ExitErr(err)
 			}
 		}
 		cmd.PrivateKey = tls.Files.PrivateKey
diff --git a/client/go/internal/admin/deploy/fetch.go b/client/go/internal/admin/deploy/fetch.go
index 9b4a927882d..010c0b1f324 100644
--- a/client/go/internal/admin/deploy/fetch.go
+++ b/client/go/internal/admin/deploy/fetch.go
@@ -12,7 +12,7 @@ import (
 	"strconv"
 	"strings"
 
-	"github.com/vespa-engine/vespa/client/go/internal/util"
+	"github.com/vespa-engine/vespa/client/go/internal/osutil"
 )
 
 // main entry point for vespa-deploy fetch
@@ -90,7 +90,7 @@ func getPartAfterSlash(path string) string {
 		return parts[idx-1]
 	}
 	if idx == 0 {
-		util.JustExitMsg("cannot find part after slash: " + path)
+		osutil.ExitMsg("cannot find part after slash: " + path)
 	}
 	return parts[idx]
 }
diff --git a/client/go/internal/admin/deploy/persist.go b/client/go/internal/admin/deploy/persist.go
index 2c40606e1ab..781fc64106a 100644
--- a/client/go/internal/admin/deploy/persist.go
+++ b/client/go/internal/admin/deploy/persist.go
@@ -10,7 +10,7 @@ import (
 	"path/filepath"
 
 	"github.com/vespa-engine/vespa/client/go/internal/admin/trace"
-	"github.com/vespa-engine/vespa/client/go/internal/util"
+	"github.com/vespa-engine/vespa/client/go/internal/osutil"
 )
 
 const (
@@ -43,11 +43,11 @@ func configsourceUrlUsedFile() string {
 func createTenantDir(tenant string) string {
 	vespaDeployTempDir, err := createVespaDeployDir()
 	if err != nil {
-		util.JustExitWith(err)
+		osutil.ExitErr(err)
 	}
 	tdir := filepath.Join(vespaDeployTempDir, tenant)
 	if err := os.MkdirAll(tdir, 0700); err != nil {
-		util.JustExitWith(err)
+		osutil.ExitErr(err)
 	}
 	return tdir
 }
@@ -80,7 +80,7 @@ func getSessionIdFromFile(tenant string) string {
 	fn := filepath.Join(dir, sessionIdFileName)
 	bytes, err := os.ReadFile(fn)
 	if err != nil {
-		util.JustExitMsg("Could not read session id from file, and no session id supplied as argument. Exiting.")
+		osutil.ExitMsg("Could not read session id from file, and no session id supplied as argument. Exiting.")
 	}
 	trace.Trace("Session-id", string(bytes), "found from file", fn)
 	return string(bytes)
diff --git a/client/go/internal/admin/deploy/urls.go b/client/go/internal/admin/deploy/urls.go
index e9110bd9463..e840f4de29c 100644
--- a/client/go/internal/admin/deploy/urls.go
+++ b/client/go/internal/admin/deploy/urls.go
@@ -9,7 +9,7 @@ import (
 	"strings"
 
 	"github.com/vespa-engine/vespa/client/go/internal/admin/trace"
-	"github.com/vespa-engine/vespa/client/go/internal/util"
+	"github.com/vespa-engine/vespa/client/go/internal/osutil"
 	"github.com/vespa-engine/vespa/client/go/internal/vespa"
 )
 
@@ -28,7 +28,7 @@ func makeConfigsourceUrls(opts *Options) []string {
 	var results = make([]string, 0, 3)
 	if opts.ServerHost == "" {
 		home := vespa.FindHome()
-		backticks := util.BackTicksForwardStderr
+		backticks := osutil.BackTicksForwardStderr
 		configsources, _ := backticks.Run(home+"/bin/vespa-print-default", "configservers_http")
 		for _, src := range strings.Split(configsources, "\n") {
 			colonParts := strings.Split(src, ":")
diff --git a/client/go/internal/admin/jvm/application_container.go b/client/go/internal/admin/jvm/application_container.go
index c525ea77949..3806dfea302 100644
--- a/client/go/internal/admin/jvm/application_container.go
+++ b/client/go/internal/admin/jvm/application_container.go
@@ -4,14 +4,16 @@
 package jvm
 
 import (
+	"crypto/md5"
 	"fmt"
+	"io"
 	"os"
 
 	"github.com/vespa-engine/vespa/client/go/internal/admin/defaults"
 	"github.com/vespa-engine/vespa/client/go/internal/admin/envvars"
 	"github.com/vespa-engine/vespa/client/go/internal/admin/prog"
 	"github.com/vespa-engine/vespa/client/go/internal/admin/trace"
-	"github.com/vespa-engine/vespa/client/go/internal/util"
+	"github.com/vespa-engine/vespa/client/go/internal/osutil"
 )
 
 const (
@@ -22,6 +24,13 @@ type ApplicationContainer struct {
 	containerBase
 }
 
+func md5Hex(text string) string {
+	hasher := md5.New()
+	io.WriteString(hasher, text)
+	hash := hasher.Sum(nil)
+	return fmt.Sprintf("%x", hash)
+}
+
 func (a *ApplicationContainer) ArgForMain() string {
 	dir := defaults.UnderVespaHome("lib/jars")
 	return fmt.Sprintf("file:%s/%s", dir, JAR_FOR_APPLICATION_CONTAINER)
@@ -31,7 +40,7 @@ func (a *ApplicationContainer) Discriminator() string {
 	cfgId := a.ConfigId()
 	if cfgId != "" {
 		trace.Trace("Discriminator: using md5 of", cfgId)
-		return util.Md5Hex(cfgId + "\n")
+		return md5Hex(cfgId + "\n")
 	}
 	svcName := a.ServiceName()
 	if svcName != "" {
@@ -40,7 +49,7 @@ func (a *ApplicationContainer) Discriminator() string {
 	}
 	pid := os.Getpid()
 	trace.Trace("Discriminator: using md5 of", pid)
-	return util.Md5Hex(fmt.Sprintf("%d", pid))
+	return md5Hex(fmt.Sprintf("%d", pid))
 }
 
 func (a *ApplicationContainer) addJdiscProperties() {
@@ -168,6 +177,6 @@ func (c *ApplicationContainer) exportExtraEnv(ps *prog.Spec) {
 	if c.ConfigId() != "" {
 		ps.Setenv(envvars.VESPA_CONFIG_ID, c.ConfigId())
 	} else {
-		util.JustExitMsg("application container requires a config id")
+		osutil.ExitMsg("application container requires a config id")
 	}
 }
diff --git a/client/go/internal/util/md5_test.go b/client/go/internal/admin/jvm/application_container_test.go
index ac3bc6a9546..3a062edee16 100644
--- a/client/go/internal/util/md5_test.go
+++ b/client/go/internal/admin/jvm/application_container_test.go
@@ -1,5 +1,7 @@
 // Copyright Vespa.ai. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
-package util
+// Author: arnej
+
+package jvm
 
 import (
 	"testing"
@@ -8,6 +10,6 @@ import (
 )
 
 func TestMD5SimpleInputs(t *testing.T) {
-	assert.Equal(t, "d41d8cd98f00b204e9800998ecf8427e", Md5Hex(""))
-	assert.Equal(t, "4044e8209f286312a68bbb54f8714922", Md5Hex("admin/cluster-controllers/0\n"))
+	assert.Equal(t, "d41d8cd98f00b204e9800998ecf8427e", md5Hex(""))
+	assert.Equal(t, "4044e8209f286312a68bbb54f8714922", md5Hex("admin/cluster-controllers/0\n"))
 }
diff --git a/client/go/internal/admin/jvm/container.go b/client/go/internal/admin/jvm/container.go
index 086ca8dde25..852bdb2464b 100644
--- a/client/go/internal/admin/jvm/container.go
+++ b/client/go/internal/admin/jvm/container.go
@@ -10,7 +10,8 @@ import (
 
 	"github.com/vespa-engine/vespa/client/go/internal/admin/prog"
 	"github.com/vespa-engine/vespa/client/go/internal/admin/trace"
-	"github.com/vespa-engine/vespa/client/go/internal/util"
+	"github.com/vespa-engine/vespa/client/go/internal/list"
+	"github.com/vespa-engine/vespa/client/go/internal/osutil"
 )
 
 type Container interface {
@@ -60,7 +61,7 @@ func readableEnv(env map[string]string) string {
 }
 
 func (cb *containerBase) Exec() {
-	argv := util.ArrayListOf(cb.JvmOptions().Args())
+	argv := list.ArrayListOf(cb.JvmOptions().Args())
 	argv.Insert(0, "java")
 	p := prog.NewSpec(argv)
 	p.ConfigureNumaCtl()
@@ -71,5 +72,5 @@ func (cb *containerBase) Exec() {
 	trace.Info("JVM env:", readableEnv(p.Env))
 	trace.Info("JVM exec:", argv)
 	err := p.Run()
-	util.JustExitWith(err)
+	osutil.ExitErr(err)
 }
diff --git a/client/go/internal/admin/jvm/env.go b/client/go/internal/admin/jvm/env.go
index 5c1e938d46b..ab7b005668b 100644
--- a/client/go/internal/admin/jvm/env.go
+++ b/client/go/internal/admin/jvm/env.go
@@ -11,7 +11,8 @@ import (
 	"github.com/vespa-engine/vespa/client/go/internal/admin/envvars"
 	"github.com/vespa-engine/vespa/client/go/internal/admin/prog"
 	"github.com/vespa-engine/vespa/client/go/internal/admin/trace"
-	"github.com/vespa-engine/vespa/client/go/internal/util"
+	"github.com/vespa-engine/vespa/client/go/internal/ioutil"
+	"github.com/vespa-engine/vespa/client/go/internal/osutil"
 )
 
 func (opts *Options) exportEnvSettings(ps *prog.Spec) {
@@ -33,7 +34,7 @@ func (opts *Options) exportEnvSettings(ps *prog.Spec) {
 	if preload := ps.Getenv(envvars.PRELOAD); preload != "" {
 		checked := []string{}
 		for _, fileName := range strings.Split(preload, ":") {
-			if util.PathExists(fileName) {
+			if ioutil.Exists(fileName) {
 				checked = append(checked, fileName)
 			} else {
 				trace.Info("File in PRELOAD missing, skipped:", fileName)
@@ -45,6 +46,6 @@ func (opts *Options) exportEnvSettings(ps *prog.Spec) {
 			ps.Setenv(envvars.LD_PRELOAD, preload)
 		}
 	}
-	util.OptionallyReduceTimerFrequency()
+	osutil.OptionallyReduceTimerFrequency()
 	c.exportExtraEnv(ps)
 }
diff --git a/client/go/internal/admin/jvm/mem_avail.go b/client/go/internal/admin/jvm/mem_avail.go
index bcc475e8ba8..df5acf79043 100644
--- a/client/go/internal/admin/jvm/mem_avail.go
+++ b/client/go/internal/admin/jvm/mem_avail.go
@@ -10,7 +10,7 @@ import (
 	"strings"
 
 	"github.com/vespa-engine/vespa/client/go/internal/admin/trace"
-	"github.com/vespa-engine/vespa/client/go/internal/util"
+	"github.com/vespa-engine/vespa/client/go/internal/osutil"
 )
 
 func parseFree(txt string) AmountOfMemory {
@@ -91,7 +91,7 @@ func vespa_cg2get_impl(rootdir, limitname string) (output string, err error) {
 
 func getAvailableMemory() AmountOfMemory {
 	result := BytesOfMemory(0)
-	backticks := util.BackTicksWithStderr
+	backticks := osutil.BackTicksWithStderr
 	freeOutput, err := backticks.Run("free", "-m")
 	if err == nil {
 		result = parseFree(freeOutput)
diff --git a/client/go/internal/admin/jvm/options.go b/client/go/internal/admin/jvm/options.go
index a788fb0cca9..30c07526a40 100644
--- a/client/go/internal/admin/jvm/options.go
+++ b/client/go/internal/admin/jvm/options.go
@@ -10,22 +10,23 @@ import (
 
 	"github.com/vespa-engine/vespa/client/go/internal/admin/defaults"
 	"github.com/vespa-engine/vespa/client/go/internal/admin/trace"
-	"github.com/vespa-engine/vespa/client/go/internal/util"
+	"github.com/vespa-engine/vespa/client/go/internal/list"
+	"github.com/vespa-engine/vespa/client/go/internal/osutil"
 	"github.com/vespa-engine/vespa/client/go/internal/vespa"
 )
 
 type Options struct {
 	container   Container
 	classPath   []string
-	jvmArgs     util.ArrayList[string]
+	jvmArgs     list.ArrayList[string]
 	mainClass   string
 	jarWithDeps string
-	fixSpec     util.FixSpec
+	fixSpec     osutil.FixSpec
 }
 
 func NewOptions(c Container) *Options {
 	vespaUid, vespaGid := vespa.FindVespaUidAndGid()
-	fixSpec := util.FixSpec{
+	fixSpec := osutil.FixSpec{
 		UserId:   vespaUid,
 		GroupId:  vespaGid,
 		DirMode:  0755,
@@ -79,7 +80,7 @@ func (opts *Options) AddJvmArgsFromString(args string) {
 
 func (opts *Options) ConfigureCpuCount(cnt int) {
 	if cnt <= 0 {
-		out, err := util.BackTicksForwardStderr.Run("nproc", "--all")
+		out, err := osutil.BackTicksForwardStderr.Run("nproc", "--all")
 		if err != nil {
 			trace.Trace("failed nproc:", err)
 		} else {
diff --git a/client/go/internal/admin/jvm/properties.go b/client/go/internal/admin/jvm/properties.go
index 446f218a2ad..d0016e03b51 100644
--- a/client/go/internal/admin/jvm/properties.go
+++ b/client/go/internal/admin/jvm/properties.go
@@ -11,7 +11,7 @@ import (
 	"strings"
 
 	"github.com/vespa-engine/vespa/client/go/internal/admin/trace"
-	"github.com/vespa-engine/vespa/client/go/internal/util"
+	"github.com/vespa-engine/vespa/client/go/internal/osutil"
 )
 
 // quote as specified in JDK source file java.base/share/classes/java/util/Properties.java
@@ -101,6 +101,6 @@ func writeEnvAsProperties(envv []string, propsFile string) {
 	trace.Trace("write props file:", propsFile)
 	err := os.WriteFile(propsFile, envAsProperties(envv), 0600)
 	if err != nil {
-		util.JustExitWith(err)
+		osutil.ExitErr(err)
 	}
 }
diff --git a/client/go/internal/admin/jvm/qr_start_cfg.go b/client/go/internal/admin/jvm/qr_start_cfg.go
index 4edb02b2a84..a14ab0d1946 100644
--- a/client/go/internal/admin/jvm/qr_start_cfg.go
+++ b/client/go/internal/admin/jvm/qr_start_cfg.go
@@ -8,7 +8,7 @@ import (
 	"strings"
 
 	"github.com/vespa-engine/vespa/client/go/internal/admin/trace"
-	"github.com/vespa-engine/vespa/client/go/internal/util"
+	"github.com/vespa-engine/vespa/client/go/internal/osutil"
 )
 
 type QrStartConfig struct {
@@ -42,10 +42,10 @@ func (a *ApplicationContainer) getQrStartCfg() *QrStartConfig {
 		"-n", "search.config.qr-start",
 		"-i", a.ConfigId(),
 	}
-	backticks := util.BackTicksForwardStderr
+	backticks := osutil.BackTicksForwardStderr
 	data, err := backticks.Run("vespa-get-config", args...)
 	if err != nil {
-		util.JustExitMsg("could not get qr-start config: " + err.Error())
+		osutil.ExitMsg("could not get qr-start config: " + err.Error())
 	} else {
 		codec := json.NewDecoder(strings.NewReader(data))
 		err = codec.Decode(&parsedJson)
diff --git a/client/go/internal/admin/jvm/standalone_container.go b/client/go/internal/admin/jvm/standalone_container.go
index 859aea9157d..20031bc7725 100644
--- a/client/go/internal/admin/jvm/standalone_container.go
+++ b/client/go/internal/admin/jvm/standalone_container.go
@@ -9,7 +9,8 @@ import (
 	"github.com/vespa-engine/vespa/client/go/internal/admin/defaults"
 	"github.com/vespa-engine/vespa/client/go/internal/admin/envvars"
 	"github.com/vespa-engine/vespa/client/go/internal/admin/prog"
-	"github.com/vespa-engine/vespa/client/go/internal/util"
+	"github.com/vespa-engine/vespa/client/go/internal/ioutil"
+	"github.com/vespa-engine/vespa/client/go/internal/osutil"
 )
 
 const (
@@ -78,9 +79,9 @@ func (a *StandaloneContainer) addJdiscProperties() {
 func (c *StandaloneContainer) exportExtraEnv(ps *prog.Spec) {
 	vespaHome := defaults.VespaHome()
 	app := fmt.Sprintf("%s/conf/%s-app", vespaHome, c.ServiceName())
-	if util.IsDirectory(app) {
+	if ioutil.IsDir(app) {
 		ps.Setenv(envvars.STANDALONE_JDISC_APP_LOCATION, app)
 	} else {
-		util.JustExitMsg("standalone container requires an application directory, missing: " + app)
+		osutil.ExitMsg("standalone container requires an application directory, missing: " + app)
 	}
 }
diff --git a/client/go/internal/admin/jvm/zk_locks.go b/client/go/internal/admin/jvm/zk_locks.go
index 90a05f94905..3f0c8ea3301 100644
--- a/client/go/internal/admin/jvm/zk_locks.go
+++ b/client/go/internal/admin/jvm/zk_locks.go
@@ -8,7 +8,7 @@ import (
 
 	"github.com/vespa-engine/vespa/client/go/internal/admin/defaults"
 	"github.com/vespa-engine/vespa/client/go/internal/admin/trace"
-	"github.com/vespa-engine/vespa/client/go/internal/util"
+	"github.com/vespa-engine/vespa/client/go/internal/osutil"
 )
 
 const (
@@ -16,12 +16,12 @@ const (
 )
 
 func RemoveStaleZkLocks(c Container) {
-	backticks := util.BackTicksWithStderr
+	backticks := osutil.BackTicksWithStderr
 	cmd := fmt.Sprintf("rm -f '%s/%s.%s'*lck", defaults.VespaHome(), ZOOKEEPER_LOG_FILE_PREFIX, c.ServiceName())
 	trace.Trace("cleaning locks:", cmd)
 	out, err := backticks.Run("/bin/sh", "-c", cmd)
 	if err != nil {
 		trace.Warning("Failure [", out, "] when running command:", cmd)
-		util.JustExitWith(err)
+		osutil.ExitErr(err)
 	}
 }
diff --git a/client/go/internal/admin/prog/numactl.go b/client/go/internal/admin/prog/numactl.go
index da159529ec0..58bec66e986 100644
--- a/client/go/internal/admin/prog/numactl.go
+++ b/client/go/internal/admin/prog/numactl.go
@@ -10,7 +10,7 @@ import (
 
 	"github.com/vespa-engine/vespa/client/go/internal/admin/envvars"
 	"github.com/vespa-engine/vespa/client/go/internal/admin/trace"
-	"github.com/vespa-engine/vespa/client/go/internal/util"
+	"github.com/vespa-engine/vespa/client/go/internal/osutil"
 )
 
 const (
@@ -23,7 +23,7 @@ func (p *Spec) ConfigureNumaCtl() {
 	if p.Getenv(envvars.VESPA_NO_NUMACTL) != "" {
 		return
 	}
-	backticks := util.BackTicksIgnoreStderr
+	backticks := osutil.BackTicksIgnoreStderr
 	out, err := backticks.Run(NUMACTL_PROG, "--hardware")
 	trace.Debug("numactl --hardware says:", out)
 	if err != nil {
diff --git a/client/go/internal/admin/prog/run.go b/client/go/internal/admin/prog/run.go
index 7dafbad1446..31a88610697 100644
--- a/client/go/internal/admin/prog/run.go
+++ b/client/go/internal/admin/prog/run.go
@@ -5,7 +5,7 @@ package prog
 
 import (
 	"github.com/vespa-engine/vespa/client/go/internal/admin/envvars"
-	"github.com/vespa-engine/vespa/client/go/internal/util"
+	"github.com/vespa-engine/vespa/client/go/internal/osutil"
 )
 
 func (spec *Spec) Run() error {
@@ -22,5 +22,5 @@ func (spec *Spec) Run() error {
 		spec.Setenv(envvars.LD_PRELOAD, spec.vespaMallocPreload)
 	}
 	envv := spec.EffectiveEnv()
-	return util.Execvpe(prog, args, envv)
+	return osutil.Execvpe(prog, args, envv)
 }
diff --git a/client/go/internal/admin/prog/valgrind.go b/client/go/internal/admin/prog/valgrind.go
index 301146bd444..a8a41b95245 100644
--- a/client/go/internal/admin/prog/valgrind.go
+++ b/client/go/internal/admin/prog/valgrind.go
@@ -10,7 +10,7 @@ import (
 
 	"github.com/vespa-engine/vespa/client/go/internal/admin/envvars"
 	"github.com/vespa-engine/vespa/client/go/internal/admin/trace"
-	"github.com/vespa-engine/vespa/client/go/internal/util"
+	"github.com/vespa-engine/vespa/client/go/internal/osutil"
 	"github.com/vespa-engine/vespa/client/go/internal/vespa"
 )
 
@@ -23,7 +23,7 @@ func (p *Spec) ConfigureValgrind() {
 	p.shouldUseCallgrind = false
 	if p.MatchesListEnv(envvars.VESPA_USE_VALGRIND) {
 		trace.Trace("using valgrind as", p.Program, "has basename in", envvars.VESPA_USE_VALGRIND)
-		backticks := util.BackTicksWithStderr
+		backticks := osutil.BackTicksWithStderr
 		out, err := backticks.Run(VALGRIND_PROG, "--help")
 		if err != nil {
 			trace.Trace("trial run of valgrind fails:", err, "=>", out)
diff --git a/client/go/internal/admin/prog/valgrind_test.go b/client/go/internal/admin/prog/valgrind_test.go
index 5bc9c1625fe..30dcca0c724 100644
--- a/client/go/internal/admin/prog/valgrind_test.go
+++ b/client/go/internal/admin/prog/valgrind_test.go
@@ -10,7 +10,7 @@ import (
 
 	"github.com/stretchr/testify/assert"
 	"github.com/vespa-engine/vespa/client/go/internal/admin/trace"
-	"github.com/vespa-engine/vespa/client/go/internal/util"
+	"github.com/vespa-engine/vespa/client/go/internal/osutil"
 )
 
 var tmpBin string
@@ -22,7 +22,7 @@ func useMock(prog, target string) {
 	os.Remove(symlink)
 	err := os.Symlink(mock, symlink)
 	if err != nil {
-		util.JustExitWith(err)
+		osutil.ExitErr(err)
 	}
 }
 
diff --git a/client/go/internal/admin/vespa-wrapper/configserver/check.go b/client/go/internal/admin/vespa-wrapper/configserver/check.go
index 73270271051..a9c1c09348e 100644
--- a/client/go/internal/admin/vespa-wrapper/configserver/check.go
+++ b/client/go/internal/admin/vespa-wrapper/configserver/check.go
@@ -8,7 +8,7 @@ import (
 
 	"github.com/vespa-engine/vespa/client/go/internal/admin/defaults"
 	"github.com/vespa-engine/vespa/client/go/internal/admin/trace"
-	"github.com/vespa-engine/vespa/client/go/internal/util"
+	"github.com/vespa-engine/vespa/client/go/internal/osutil"
 )
 
 func checkIsConfigserver(myname string) {
@@ -20,5 +20,5 @@ func checkIsConfigserver(myname string) {
 		}
 	}
 	trace.Warning("only these hosts should run a config server:", onlyHosts)
-	util.JustExitMsg(fmt.Sprintf("this host [%s] should not run a config server", myname))
+	osutil.ExitMsg(fmt.Sprintf("this host [%s] should not run a config server", myname))
 }
diff --git a/client/go/internal/admin/vespa-wrapper/configserver/env.go b/client/go/internal/admin/vespa-wrapper/configserver/env.go
index 3b43fc269f8..b4dac91d275 100644
--- a/client/go/internal/admin/vespa-wrapper/configserver/env.go
+++ b/client/go/internal/admin/vespa-wrapper/configserver/env.go
@@ -8,7 +8,7 @@ import (
 	"os"
 
 	"github.com/vespa-engine/vespa/client/go/internal/admin/envvars"
-	"github.com/vespa-engine/vespa/client/go/internal/util"
+	"github.com/vespa-engine/vespa/client/go/internal/osutil"
 )
 
 func exportSettings(vespaHome string) {
@@ -27,5 +27,5 @@ func exportSettings(vespaHome string) {
 	os.Setenv(envvars.STANDALONE_JDISC_APP_LOCATION, app)
 	os.Setenv(envvars.STANDALONE_JDISC_DEPLOYMENT_PROFILE, "configserver")
 	os.Setenv(envvars.MALLOC_ARENA_MAX, "1")
-	util.OptionallyReduceTimerFrequency()
+	osutil.OptionallyReduceTimerFrequency()
 }
diff --git a/client/go/internal/admin/vespa-wrapper/configserver/fix_dirs_and_files.go b/client/go/internal/admin/vespa-wrapper/configserver/fix_dirs_and_files.go
index 87f5f13d9d0..349366cb928 100644
--- a/client/go/internal/admin/vespa-wrapper/configserver/fix_dirs_and_files.go
+++ b/client/go/internal/admin/vespa-wrapper/configserver/fix_dirs_and_files.go
@@ -4,13 +4,13 @@
 package configserver
 
 import (
-	"github.com/vespa-engine/vespa/client/go/internal/util"
+	"github.com/vespa-engine/vespa/client/go/internal/osutil"
 	"github.com/vespa-engine/vespa/client/go/internal/vespa"
 )
 
-func makeFixSpec() util.FixSpec {
+func makeFixSpec() osutil.FixSpec {
 	vespaUid, vespaGid := vespa.FindVespaUidAndGid()
-	return util.FixSpec{
+	return osutil.FixSpec{
 		UserId:   vespaUid,
 		GroupId:  vespaGid,
 		DirMode:  0755,
@@ -18,7 +18,7 @@ func makeFixSpec() util.FixSpec {
 	}
 }
 
-func fixDirsAndFiles(fixSpec util.FixSpec) {
+func fixDirsAndFiles(fixSpec osutil.FixSpec) {
 	fixSpec.FixDir("var/zookeeper")
 	fixSpec.FixDir("var/zookeeper/conf")
 	fixSpec.FixDir("var/zookeeper/version-2")
diff --git a/client/go/internal/admin/vespa-wrapper/configserver/logd.go b/client/go/internal/admin/vespa-wrapper/configserver/logd.go
index 99fc9aa622a..3d51ce317a2 100644
--- a/client/go/internal/admin/vespa-wrapper/configserver/logd.go
+++ b/client/go/internal/admin/vespa-wrapper/configserver/logd.go
@@ -8,12 +8,12 @@ import (
 
 	"github.com/vespa-engine/vespa/client/go/internal/admin/envvars"
 	"github.com/vespa-engine/vespa/client/go/internal/admin/trace"
-	"github.com/vespa-engine/vespa/client/go/internal/util"
+	"github.com/vespa-engine/vespa/client/go/internal/osutil"
 )
 
 func maybeStartLogd() {
 	if os.Getenv(envvars.VESPA_CONFIGSERVER_MULTITENANT) == "true" {
-		backticks := util.BackTicksForwardStderr
+		backticks := osutil.BackTicksForwardStderr
 		out, err := backticks.Run("libexec/vespa/start-logd")
 		if err != nil {
 			panic(err)
diff --git a/client/go/internal/admin/vespa-wrapper/configserver/runserver.go b/client/go/internal/admin/vespa-wrapper/configserver/runserver.go
index 25935c814e7..5fdaa5fa9b8 100644
--- a/client/go/internal/admin/vespa-wrapper/configserver/runserver.go
+++ b/client/go/internal/admin/vespa-wrapper/configserver/runserver.go
@@ -8,7 +8,9 @@ import (
 
 	"github.com/vespa-engine/vespa/client/go/internal/admin/defaults"
 	"github.com/vespa-engine/vespa/client/go/internal/admin/trace"
-	"github.com/vespa-engine/vespa/client/go/internal/util"
+	"github.com/vespa-engine/vespa/client/go/internal/ioutil"
+	"github.com/vespa-engine/vespa/client/go/internal/list"
+	"github.com/vespa-engine/vespa/client/go/internal/osutil"
 )
 
 const (
@@ -27,25 +29,25 @@ func (rs *RunServer) PidFile() string {
 
 func (rs *RunServer) ProgPath() string {
 	p := fmt.Sprintf("%s/bin64/%s", defaults.VespaHome(), PROG_NAME)
-	if util.IsExecutableFile(p) {
+	if ioutil.IsExecutable(p) {
 		return p
 	}
 	p = fmt.Sprintf("%s/bin/%s", defaults.VespaHome(), PROG_NAME)
-	if util.IsExecutableFile(p) {
+	if ioutil.IsExecutable(p) {
 		return p
 	}
 	panic(fmt.Errorf("not an executable file: %s", p))
 }
 
 func (rs *RunServer) WouldRun() bool {
-	backticks := util.BackTicksForwardStderr
+	backticks := osutil.BackTicksForwardStderr
 	out, err := backticks.Run(rs.ProgPath(), "-s", rs.ServiceName, "-p", rs.PidFile(), "-W")
 	trace.Trace("output from -W:", out, "error:", err)
 	return err == nil
 }
 
 func (rs *RunServer) Exec(prog string) {
-	argv := util.ArrayList[string]{
+	argv := list.ArrayList[string]{
 		PROG_NAME,
 		"-s", rs.ServiceName,
 		"-r", "30",
@@ -54,6 +56,6 @@ func (rs *RunServer) Exec(prog string) {
 		prog,
 	}
 	argv.AppendAll(rs.Args...)
-	err := util.Execvp(rs.ProgPath(), argv)
-	util.JustExitWith(err)
+	err := osutil.Execvp(rs.ProgPath(), argv)
+	osutil.ExitErr(err)
 }
diff --git a/client/go/internal/admin/vespa-wrapper/configserver/start.go b/client/go/internal/admin/vespa-wrapper/configserver/start.go
index 91064b21849..452ea714100 100644
--- a/client/go/internal/admin/vespa-wrapper/configserver/start.go
+++ b/client/go/internal/admin/vespa-wrapper/configserver/start.go
@@ -9,7 +9,7 @@ import (
 	"github.com/vespa-engine/vespa/client/go/internal/admin/envvars"
 	"github.com/vespa-engine/vespa/client/go/internal/admin/jvm"
 	"github.com/vespa-engine/vespa/client/go/internal/admin/trace"
-	"github.com/vespa-engine/vespa/client/go/internal/util"
+	"github.com/vespa-engine/vespa/client/go/internal/osutil"
 	"github.com/vespa-engine/vespa/client/go/internal/vespa"
 )
 
@@ -37,7 +37,7 @@ func commonPreChecks() (veHome string) {
 	checkIsConfigserver(veHost)
 	e = os.Chdir(veHome)
 	if e != nil {
-		util.JustExitWith(e)
+		osutil.ExitErr(e)
 	}
 	return
 }
@@ -45,8 +45,8 @@ func commonPreChecks() (veHome string) {
 func JustStartConfigserver() int {
 	vespaHome := commonPreChecks()
 	vespa.CheckCorrectUser()
-	util.TuneResourceLimits()
-	util.TuneLogging(SERVICE_NAME, "com.google.api.client.http.HttpTransport", "config=off")
+	osutil.TuneResourceLimits()
+	osutil.TuneLogging(SERVICE_NAME, "com.google.api.client.http.HttpTransport", "config=off")
 	exportSettings(vespaHome)
 	removeStaleZkLocks(vespaHome)
 	c := jvm.NewStandaloneContainer(SERVICE_NAME)
@@ -76,7 +76,7 @@ func runConfigserverWithRunserver() int {
 func StartConfigserverEtc() int {
 	vespaHome := commonPreChecks()
 	vespa.RunPreStart()
-	util.TuneResourceLimits()
+	osutil.TuneResourceLimits()
 	fixSpec := makeFixSpec()
 	fixDirsAndFiles(fixSpec)
 	exportSettings(vespaHome)
diff --git a/client/go/internal/admin/vespa-wrapper/configserver/zk.go b/client/go/internal/admin/vespa-wrapper/configserver/zk.go
index 2fee37f0662..c14c8fe8e29 100644
--- a/client/go/internal/admin/vespa-wrapper/configserver/zk.go
+++ b/client/go/internal/admin/vespa-wrapper/configserver/zk.go
@@ -7,7 +7,7 @@ import (
 	"fmt"
 
 	"github.com/vespa-engine/vespa/client/go/internal/admin/trace"
-	"github.com/vespa-engine/vespa/client/go/internal/util"
+	"github.com/vespa-engine/vespa/client/go/internal/osutil"
 )
 
 const (
@@ -15,7 +15,7 @@ const (
 )
 
 func removeStaleZkLocks(vespaHome string) {
-	backticks := util.BackTicksIgnoreStderr
+	backticks := osutil.BackTicksIgnoreStderr
 	cmd := fmt.Sprintf("rm -f '%s/%s'*lck", vespaHome, ZOOKEEPER_LOG_FILE_PREFIX)
 	trace.Trace("cleaning locks:", cmd)
 	backticks.Run("/bin/sh", "-c", cmd)
diff --git a/client/go/internal/admin/vespa-wrapper/main.go b/client/go/internal/admin/vespa-wrapper/main.go
index ad1eee52b63..32c5f909491 100644
--- a/client/go/internal/admin/vespa-wrapper/main.go
+++ b/client/go/internal/admin/vespa-wrapper/main.go
@@ -17,7 +17,7 @@ import (
 	"github.com/vespa-engine/vespa/client/go/internal/admin/vespa-wrapper/services"
 	"github.com/vespa-engine/vespa/client/go/internal/admin/vespa-wrapper/standalone"
 	"github.com/vespa-engine/vespa/client/go/internal/admin/vespa-wrapper/startcbinary"
-	"github.com/vespa-engine/vespa/client/go/internal/util"
+	"github.com/vespa-engine/vespa/client/go/internal/osutil"
 	"github.com/vespa-engine/vespa/client/go/internal/vespa"
 )
 
@@ -99,7 +99,7 @@ func main() {
 
 func handleSimplePanic() {
 	if r := recover(); r != nil {
-		if jee, ok := r.(*util.JustExitError); ok {
+		if jee, ok := r.(*osutil.ExitError); ok {
 			fmt.Fprintln(os.Stderr, jee)
 			os.Exit(1)
 		} else {
diff --git a/client/go/internal/admin/vespa-wrapper/services/configproxy.go b/client/go/internal/admin/vespa-wrapper/services/configproxy.go
index e92b05ccc1e..bed6e980cf4 100644
--- a/client/go/internal/admin/vespa-wrapper/services/configproxy.go
+++ b/client/go/internal/admin/vespa-wrapper/services/configproxy.go
@@ -15,7 +15,7 @@ import (
 	"github.com/vespa-engine/vespa/client/go/internal/admin/envvars"
 	"github.com/vespa-engine/vespa/client/go/internal/admin/jvm"
 	"github.com/vespa-engine/vespa/client/go/internal/admin/trace"
-	"github.com/vespa-engine/vespa/client/go/internal/util"
+	"github.com/vespa-engine/vespa/client/go/internal/osutil"
 	"github.com/vespa-engine/vespa/client/go/internal/vespa"
 )
 
@@ -30,9 +30,9 @@ func JustRunConfigproxy() int {
 	vespa.CheckCorrectUser()
 	configsources := defaults.VespaConfigserverRpcAddrs()
 	if len(configsources) < 1 {
-		util.JustExitMsg("could not find any configservers")
+		osutil.ExitMsg("could not find any configservers")
 	}
-	util.TuneResourceLimits()
+	osutil.TuneResourceLimits()
 	c := jvm.NewConfigProxyJvm(PROXY_SERVICE_NAME)
 	userargs := os.Getenv(envvars.VESPA_CONFIGPROXY_JVMARGS)
 	c.ConfigureOptions(configsources, userargs)
@@ -68,7 +68,7 @@ func startProxyWithRunserver() {
 
 func waitForProxyResponse() bool {
 	hname, _ := vespa.FindOurHostname()
-	backtick := util.BackTicksWithStderr
+	backtick := osutil.BackTicksWithStderr
 	start := time.Now()
 	fmt.Printf("Waiting for config proxy to start\n")
 	for sleepcount := 0; sleepcount < 1800; sleepcount++ {
@@ -135,7 +135,7 @@ func StartConfigproxy() int {
 }
 
 func stopProxyWithRunserver() {
-	_, err := util.SystemCommand.Run("vespa-runserver",
+	_, err := osutil.SystemCommand.Run("vespa-runserver",
 		"-s", PROXY_SERVICE_NAME,
 		"-p", CONFIGPROXY_PIDFILE, "-S")
 	if err != nil {
diff --git a/client/go/internal/admin/vespa-wrapper/services/env.go b/client/go/internal/admin/vespa-wrapper/services/env.go
index 9a7ba40c73e..23cf80213d5 100644
--- a/client/go/internal/admin/vespa-wrapper/services/env.go
+++ b/client/go/internal/admin/vespa-wrapper/services/env.go
@@ -8,7 +8,7 @@ import (
 	"os"
 
 	"github.com/vespa-engine/vespa/client/go/internal/admin/envvars"
-	"github.com/vespa-engine/vespa/client/go/internal/util"
+	"github.com/vespa-engine/vespa/client/go/internal/osutil"
 )
 
 func exportSettings(vespaHome string) {
@@ -21,5 +21,5 @@ func exportSettings(vespaHome string) {
 	os.Setenv(envvars.JAVAVM_LD_PRELOAD, "")
 	os.Setenv(envvars.LD_PRELOAD, "")
 	os.Setenv(envvars.MALLOC_ARENA_MAX, "1")
-	util.OptionallyReduceTimerFrequency()
+	osutil.OptionallyReduceTimerFrequency()
 }
diff --git a/client/go/internal/admin/vespa-wrapper/services/prechecks.go b/client/go/internal/admin/vespa-wrapper/services/prechecks.go
index bb6bf55e06b..93a53707ba2 100644
--- a/client/go/internal/admin/vespa-wrapper/services/prechecks.go
+++ b/client/go/internal/admin/vespa-wrapper/services/prechecks.go
@@ -8,7 +8,7 @@ import (
 
 	"github.com/vespa-engine/vespa/client/go/internal/admin/envvars"
 	"github.com/vespa-engine/vespa/client/go/internal/admin/trace"
-	"github.com/vespa-engine/vespa/client/go/internal/util"
+	"github.com/vespa-engine/vespa/client/go/internal/osutil"
 	"github.com/vespa-engine/vespa/client/go/internal/vespa"
 )
 
@@ -31,7 +31,7 @@ func commonPreChecks() (veHome, veHost string) {
 	}
 	err = os.Chdir(veHome)
 	if err != nil {
-		util.JustExitWith(err)
+		osutil.ExitErr(err)
 	}
 	return
 }
diff --git a/client/go/internal/admin/vespa-wrapper/services/sentinel.go b/client/go/internal/admin/vespa-wrapper/services/sentinel.go
index 7694c930731..e489bf70ded 100644
--- a/client/go/internal/admin/vespa-wrapper/services/sentinel.go
+++ b/client/go/internal/admin/vespa-wrapper/services/sentinel.go
@@ -13,7 +13,7 @@ import (
 
 	"github.com/vespa-engine/vespa/client/go/internal/admin/envvars"
 	"github.com/vespa-engine/vespa/client/go/internal/admin/trace"
-	"github.com/vespa-engine/vespa/client/go/internal/util"
+	"github.com/vespa-engine/vespa/client/go/internal/osutil"
 	"github.com/vespa-engine/vespa/client/go/internal/vespa"
 )
 
@@ -48,7 +48,7 @@ func startSentinelWithRunserver() {
 }
 
 func waitForSentinelPid() bool {
-	backtick := util.BackTicksWithStderr
+	backtick := osutil.BackTicksWithStderr
 	start := time.Now()
 	for sleepcount := 0; sleepcount < 1000; sleepcount++ {
 		time.Sleep(10 * time.Millisecond)
@@ -84,7 +84,7 @@ func StartConfigSentinel() int {
 }
 
 func stopSentinelWithRunserver() {
-	_, err := util.SystemCommand.Run("vespa-runserver",
+	_, err := osutil.SystemCommand.Run("vespa-runserver",
 		"-s", SENTINEL_SERVICE_NAME,
 		"-p", SENTINEL_PIDFILE, "-S")
 	if err != nil {
diff --git a/client/go/internal/admin/vespa-wrapper/services/start.go b/client/go/internal/admin/vespa-wrapper/services/start.go
index d2c2fb6f5ba..de658264669 100644
--- a/client/go/internal/admin/vespa-wrapper/services/start.go
+++ b/client/go/internal/admin/vespa-wrapper/services/start.go
@@ -10,7 +10,7 @@ import (
 
 	"github.com/vespa-engine/vespa/client/go/internal/admin/envvars"
 	"github.com/vespa-engine/vespa/client/go/internal/admin/trace"
-	"github.com/vespa-engine/vespa/client/go/internal/util"
+	"github.com/vespa-engine/vespa/client/go/internal/osutil"
 	"github.com/vespa-engine/vespa/client/go/internal/vespa"
 )
 
@@ -33,14 +33,14 @@ func StartServices() int {
 }
 
 func checkjava() {
-	backticks := util.BackTicksWithStderr
+	backticks := osutil.BackTicksWithStderr
 	out, err := backticks.Run("java", "-version")
 	if err != nil {
 		trace.Warning("cannot run 'java -version'")
-		util.JustExitWith(err)
+		osutil.ExitErr(err)
 	}
 	if !strings.Contains(out, "64-Bit Server VM") {
-		util.JustExitWith(fmt.Errorf("java must invoke the 64-bit Java VM, but -version says:\n%s\n", out))
+		osutil.ExitErr(fmt.Errorf("java must invoke the 64-bit Java VM, but -version says:\n%s\n", out))
 	}
 }
 
@@ -53,7 +53,7 @@ func VespaStartServices() int {
 	trace.Debug("common prechecks ok, running in", home, "on", host)
 	vespa.RunPreStart()
 	trace.Debug("prestart ok")
-	util.TuneResourceLimits()
+	osutil.TuneResourceLimits()
 	increase_vm_max_map_count()
 	trace.Debug("resource limits ok")
 	checkjava()
@@ -64,7 +64,7 @@ func VespaStartServices() int {
 	drop_caches()
 	err := vespa.MaybeSwitchUser("start-services")
 	if err != nil {
-		util.JustExitWith(err)
+		osutil.ExitErr(err)
 	}
 	return StartServices()
 }
diff --git a/client/go/internal/admin/vespa-wrapper/services/stop.go b/client/go/internal/admin/vespa-wrapper/services/stop.go
index 54d557847ce..c4c4787c83a 100644
--- a/client/go/internal/admin/vespa-wrapper/services/stop.go
+++ b/client/go/internal/admin/vespa-wrapper/services/stop.go
@@ -8,7 +8,7 @@ import (
 
 	"github.com/vespa-engine/vespa/client/go/internal/admin/envvars"
 	"github.com/vespa-engine/vespa/client/go/internal/admin/trace"
-	"github.com/vespa-engine/vespa/client/go/internal/util"
+	"github.com/vespa-engine/vespa/client/go/internal/osutil"
 	"github.com/vespa-engine/vespa/client/go/internal/vespa"
 )
 
@@ -21,11 +21,11 @@ func VespaStopServices() int {
 	}
 	err := vespa.LoadDefaultEnv()
 	if err != nil {
-		util.JustExitWith(err)
+		osutil.ExitErr(err)
 	}
 	err = vespa.MaybeSwitchUser("vespa-stop-services")
 	if err != nil {
-		util.JustExitWith(err)
+		osutil.ExitErr(err)
 	}
 	vespa.CheckCorrectUser()
 	trace.Debug("running as correct user")
diff --git a/client/go/internal/admin/vespa-wrapper/standalone/start.go b/client/go/internal/admin/vespa-wrapper/standalone/start.go
index add29d37671..a3703ce930c 100644
--- a/client/go/internal/admin/vespa-wrapper/standalone/start.go
+++ b/client/go/internal/admin/vespa-wrapper/standalone/start.go
@@ -9,7 +9,7 @@ import (
 
 	"github.com/vespa-engine/vespa/client/go/internal/admin/jvm"
 	"github.com/vespa-engine/vespa/client/go/internal/admin/trace"
-	"github.com/vespa-engine/vespa/client/go/internal/util"
+	"github.com/vespa-engine/vespa/client/go/internal/osutil"
 	"github.com/vespa-engine/vespa/client/go/internal/vespa"
 )
 
@@ -23,20 +23,20 @@ func commonPreChecks() {
 	veHome := vespa.FindAndVerifyVespaHome()
 	err := os.Chdir(veHome)
 	if err != nil {
-		util.JustExitWith(err)
+		osutil.ExitErr(err)
 	}
 	err = vespa.LoadDefaultEnv()
 	if err != nil {
-		util.JustExitWith(err)
+		osutil.ExitErr(err)
 	}
 }
 
 func StartStandaloneContainer(extraArgs []string) int {
 	commonPreChecks()
-	util.TuneResourceLimits()
+	osutil.TuneResourceLimits()
 	serviceName := os.Getenv("VESPA_SERVICE_NAME")
 	if serviceName == "" {
-		util.JustExitMsg("Missing service name, ensure VESPA_SERVICE_NAME is set in the environment")
+		osutil.ExitMsg("Missing service name, ensure VESPA_SERVICE_NAME is set in the environment")
 	}
 	c := jvm.NewStandaloneContainer(serviceName)
 	jvmOpts := c.JvmOptions()
diff --git a/client/go/internal/admin/vespa-wrapper/startcbinary/cmd.go b/client/go/internal/admin/vespa-wrapper/startcbinary/cmd.go
index 8902aef80df..a35f0c5b820 100644
--- a/client/go/internal/admin/vespa-wrapper/startcbinary/cmd.go
+++ b/client/go/internal/admin/vespa-wrapper/startcbinary/cmd.go
@@ -9,7 +9,8 @@ import (
 
 	"github.com/vespa-engine/vespa/client/go/internal/admin/envvars"
 	"github.com/vespa-engine/vespa/client/go/internal/admin/trace"
-	"github.com/vespa-engine/vespa/client/go/internal/util"
+	"github.com/vespa-engine/vespa/client/go/internal/ioutil"
+	"github.com/vespa-engine/vespa/client/go/internal/osutil"
 	"github.com/vespa-engine/vespa/client/go/internal/vespa"
 )
 
@@ -22,7 +23,7 @@ func Run(args []string) int {
 	spec := NewProgSpec(args)
 	err := vespa.LoadDefaultEnv()
 	if err != nil {
-		util.JustExitWith(err)
+		osutil.ExitErr(err)
 	}
 	hostname, err := vespa.FindOurHostname()
 	if err != nil {
@@ -34,12 +35,12 @@ func Run(args []string) int {
 func IsCandidate(program string) bool {
 	binary := program + "-bin"
 	if strings.Contains(binary, "/") {
-		return util.IsRegularFile(binary)
+		return ioutil.IsFile(binary)
 	} else {
 		path := strings.Split(os.Getenv(envvars.PATH), ":")
 		for _, dir := range path {
 			fn := dir + "/" + binary
-			if util.IsRegularFile(fn) {
+			if ioutil.IsFile(fn) {
 				return true
 			}
 		}
diff --git a/client/go/internal/admin/vespa-wrapper/startcbinary/tuning.go b/client/go/internal/admin/vespa-wrapper/startcbinary/tuning.go
index 898e4558152..06c20021ff6 100644
--- a/client/go/internal/admin/vespa-wrapper/startcbinary/tuning.go
+++ b/client/go/internal/admin/vespa-wrapper/startcbinary/tuning.go
@@ -4,10 +4,10 @@
 package startcbinary
 
 import (
-	"github.com/vespa-engine/vespa/client/go/internal/util"
+	"github.com/vespa-engine/vespa/client/go/internal/osutil"
 )
 
 func configureTuning() {
-	util.OptionallyReduceTimerFrequency()
-	util.TuneResourceLimits()
+	osutil.OptionallyReduceTimerFrequency()
+	osutil.TuneResourceLimits()
 }
diff --git a/client/go/internal/cli/auth/auth0/auth0.go b/client/go/internal/cli/auth/auth0/auth0.go
index 7fae6e78b61..9466e9865b5 100644
--- a/client/go/internal/cli/auth/auth0/auth0.go
+++ b/client/go/internal/cli/auth/auth0/auth0.go
@@ -14,7 +14,7 @@ import (
 	"time"
 
 	"github.com/vespa-engine/vespa/client/go/internal/cli/auth"
-	"github.com/vespa-engine/vespa/client/go/internal/util"
+	"github.com/vespa-engine/vespa/client/go/internal/httputil"
 )
 
 const (
@@ -31,7 +31,7 @@ type Credentials struct {
 
 // Client is a client for the Auth0 service.
 type Client struct {
-	httpClient    util.HTTPClient
+	httpClient    httputil.Client
 	Authenticator *auth.Authenticator // TODO: Make this private
 	options       Options
 	provider      auth0Provider
@@ -80,7 +80,7 @@ func cancelOnInterrupt() context.Context {
 
 // NewClient constructs a new Auth0 client, storing configuration in the given configPath. The client will be configured for
 // use in the given Vespa system.
-func NewClient(httpClient util.HTTPClient, options Options) (*Client, error) {
+func NewClient(httpClient httputil.Client, options Options) (*Client, error) {
 	a := Client{}
 	a.httpClient = httpClient
 	a.options = options
diff --git a/client/go/internal/cli/auth/zts/zts.go b/client/go/internal/cli/auth/zts/zts.go
index b60aa363e70..1c31ba05dd3 100644
--- a/client/go/internal/cli/auth/zts/zts.go
+++ b/client/go/internal/cli/auth/zts/zts.go
@@ -11,7 +11,7 @@ import (
 	"sync"
 	"time"
 
-	"github.com/vespa-engine/vespa/client/go/internal/util"
+	"github.com/vespa-engine/vespa/client/go/internal/httputil"
 )
 
 const (
@@ -21,7 +21,7 @@ const (
 
 // Client is a client for Athenz ZTS, an authentication token service.
 type Client struct {
-	client   util.HTTPClient
+	client   httputil.Client
 	tokenURL *url.URL
 	domain   string
 	now      func() time.Time
@@ -38,7 +38,7 @@ type Token struct {
 func (t *Token) isExpired(now time.Time) bool { return t.ExpiresAt.Sub(now) < expirySlack }
 
 // NewClient creates a new client for an Athenz ZTS service located at serviceURL.
-func NewClient(client util.HTTPClient, domain, serviceURL string) (*Client, error) {
+func NewClient(client httputil.Client, domain, serviceURL string) (*Client, error) {
 	tokenURL, err := url.Parse(serviceURL)
 	if err != nil {
 		return nil, err
diff --git a/client/go/internal/cli/cmd/api_key.go b/client/go/internal/cli/cmd/api_key.go
index 133c9db0d3b..d882c527516 100644
--- a/client/go/internal/cli/cmd/api_key.go
+++ b/client/go/internal/cli/cmd/api_key.go
@@ -10,7 +10,7 @@ import (
 
 	"github.com/fatih/color"
 	"github.com/spf13/cobra"
-	"github.com/vespa-engine/vespa/client/go/internal/util"
+	"github.com/vespa-engine/vespa/client/go/internal/ioutil"
 	"github.com/vespa-engine/vespa/client/go/internal/vespa"
 )
 
@@ -71,7 +71,7 @@ func doApiKey(cli *CLI, overwriteKey bool, args []string) error {
 		return err
 	}
 	apiKeyFile := cli.config.apiKeyPath(app.Tenant)
-	if util.PathExists(apiKeyFile) && !overwriteKey {
+	if ioutil.Exists(apiKeyFile) && !overwriteKey {
 		err := fmt.Errorf("refusing to overwrite %s", apiKeyFile)
 		cli.printErr(err, "Use -f to overwrite it")
 		printPublicKey(system, apiKeyFile, app.Tenant)
diff --git a/client/go/internal/cli/cmd/cert.go b/client/go/internal/cli/cmd/cert.go
index 6aa99a01902..3e18fafb815 100644
--- a/client/go/internal/cli/cmd/cert.go
+++ b/client/go/internal/cli/cmd/cert.go
@@ -10,7 +10,7 @@ import (
 
 	"github.com/fatih/color"
 	"github.com/spf13/cobra"
-	"github.com/vespa-engine/vespa/client/go/internal/util"
+	"github.com/vespa-engine/vespa/client/go/internal/ioutil"
 	"github.com/vespa-engine/vespa/client/go/internal/vespa"
 )
 
@@ -122,10 +122,10 @@ func doCert(cli *CLI, overwriteCertificate, skipApplicationPackage bool, args []
 
 	if !overwriteCertificate {
 		hint := "Use -f flag to force overwriting"
-		if util.PathExists(privateKeyFile.path) {
+		if ioutil.Exists(privateKeyFile.path) {
 			return errHint(fmt.Errorf("private key %s already exists", color.CyanString(privateKeyFile.path)), hint)
 		}
-		if util.PathExists(certificateFile.path) {
+		if ioutil.Exists(certificateFile.path) {
 			return errHint(fmt.Errorf("certificate %s already exists", color.CyanString(certificateFile.path)), hint)
 		}
 	}
@@ -213,7 +213,7 @@ func copyCertificate(cli *CLI, target vespa.Target, pkg vespa.ApplicationPackage
 	if err := os.MkdirAll(filepath.Dir(dstPath), 0755); err != nil {
 		return fmt.Errorf("could not create security directory: %w", err)
 	}
-	err = util.AtomicWriteFile(dstPath, data)
+	err = ioutil.AtomicWriteFile(dstPath, data)
 	if err == nil {
 		cli.printSuccess("Copied certificate from ", tlsOptions.CertificateFile, " to ", dstPath)
 	}
diff --git a/client/go/internal/cli/cmd/clone_list.go b/client/go/internal/cli/cmd/clone_list.go
index 40656841276..c6a99533c03 100644
--- a/client/go/internal/cli/cmd/clone_list.go
+++ b/client/go/internal/cli/cmd/clone_list.go
@@ -7,14 +7,14 @@ import (
 	"sort"
 	"time"
 
-	"github.com/vespa-engine/vespa/client/go/internal/util"
+	"github.com/vespa-engine/vespa/client/go/internal/httputil"
 )
 
-func listSampleApps(client util.HTTPClient) ([]string, error) {
+func listSampleApps(client httputil.Client) ([]string, error) {
 	return listSampleAppsAt("https://api.github.com/repos/vespa-engine/sample-apps/contents/", client)
 }
 
-func listSampleAppsAt(url string, client util.HTTPClient) ([]string, error) {
+func listSampleAppsAt(url string, client httputil.Client) ([]string, error) {
 	rfs, err := getRepositoryFiles(url, client)
 	if err != nil {
 		return nil, err
@@ -36,7 +36,7 @@ func listSampleAppsAt(url string, client util.HTTPClient) ([]string, error) {
 	return apps, nil
 }
 
-func getRepositoryFiles(url string, client util.HTTPClient) ([]repositoryFile, error) {
+func getRepositoryFiles(url string, client httputil.Client) ([]repositoryFile, error) {
 	req, err := http.NewRequest("GET", url, nil)
 	if err != nil {
 		return nil, err
diff --git a/client/go/internal/cli/cmd/clone_test.go b/client/go/internal/cli/cmd/clone_test.go
index 331845b3883..e783f75d9d4 100644
--- a/client/go/internal/cli/cmd/clone_test.go
+++ b/client/go/internal/cli/cmd/clone_test.go
@@ -13,8 +13,8 @@ import (
 
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
+	"github.com/vespa-engine/vespa/client/go/internal/ioutil"
 	"github.com/vespa-engine/vespa/client/go/internal/mock"
-	"github.com/vespa-engine/vespa/client/go/internal/util"
 )
 
 func TestClone(t *testing.T) {
@@ -101,9 +101,9 @@ func TestClone(t *testing.T) {
 
 func assertFiles(t *testing.T, app string) {
 	t.Helper()
-	assert.True(t, util.PathExists(filepath.Join(app, "README.md")))
-	assert.True(t, util.PathExists(filepath.Join(app, "src", "main", "application")))
-	assert.True(t, util.IsDirectory(filepath.Join(app, "src", "main", "application")))
+	assert.True(t, ioutil.Exists(filepath.Join(app, "README.md")))
+	assert.True(t, ioutil.Exists(filepath.Join(app, "src", "main", "application")))
+	assert.True(t, ioutil.IsDir(filepath.Join(app, "src", "main", "application")))
 
 	servicesStat, err := os.Stat(filepath.Join(app, "src", "main", "application", "services.xml"))
 	require.Nil(t, err)
diff --git a/client/go/internal/cli/cmd/document.go b/client/go/internal/cli/cmd/document.go
index 6892956880b..0393a9b2595 100644
--- a/client/go/internal/cli/cmd/document.go
+++ b/client/go/internal/cli/cmd/document.go
@@ -15,7 +15,8 @@ import (
 
 	"github.com/fatih/color"
 	"github.com/spf13/cobra"
-	"github.com/vespa-engine/vespa/client/go/internal/util"
+	"github.com/vespa-engine/vespa/client/go/internal/httputil"
+	"github.com/vespa-engine/vespa/client/go/internal/ioutil"
 	"github.com/vespa-engine/vespa/client/go/internal/vespa"
 	"github.com/vespa-engine/vespa/client/go/internal/vespa/document"
 )
@@ -39,7 +40,7 @@ func documentClient(cli *CLI, timeoutSecs, waitSecs int, printCurl bool) (*docum
 		Timeout:     time.Duration(timeoutSecs) * time.Second,
 		BaseURL:     docService.BaseURL,
 		NowFunc:     time.Now,
-	}, []util.HTTPClient{docService})
+	}, []httputil.Client{docService})
 	if err != nil {
 		return nil, nil, err
 	}
@@ -103,22 +104,22 @@ func readDocument(id string, timeoutSecs, waitSecs int, printCurl bool, cli *CLI
 	return printResult(cli, operationResult(true, document.Document{Id: docId}, service, result), true)
 }
 
-func operationResult(read bool, doc document.Document, service *vespa.Service, result document.Result) util.OperationResult {
+func operationResult(read bool, doc document.Document, service *vespa.Service, result document.Result) OperationResult {
 	if result.Err != nil {
-		return util.Failure(result.Err.Error())
+		return Failure(result.Err.Error())
 	}
 	bodyReader := bytes.NewReader(result.Body)
 	if result.HTTPStatus == 200 {
 		if read {
-			return util.SuccessWithPayload("Read "+doc.Id.String(), util.ReaderToJSON(bodyReader))
+			return SuccessWithPayload("Read "+doc.Id.String(), ioutil.ReaderToJSON(bodyReader))
 		} else {
-			return util.Success(doc.Operation.String() + " " + doc.Id.String())
+			return Success(doc.Operation.String() + " " + doc.Id.String())
 		}
 	}
 	if result.HTTPStatus/100 == 4 {
-		return util.FailureWithPayload("Invalid document operation: Status "+strconv.Itoa(result.HTTPStatus), util.ReaderToJSON(bodyReader))
+		return FailureWithPayload("Invalid document operation: Status "+strconv.Itoa(result.HTTPStatus), ioutil.ReaderToJSON(bodyReader))
 	}
-	return util.FailureWithPayload(service.Description()+" at "+service.BaseURL+": Status "+strconv.Itoa(result.HTTPStatus), util.ReaderToJSON(bodyReader))
+	return FailureWithPayload(service.Description()+" at "+service.BaseURL+": Status "+strconv.Itoa(result.HTTPStatus), ioutil.ReaderToJSON(bodyReader))
 }
 
 func newDocumentCmd(cli *CLI) *cobra.Command {
@@ -269,7 +270,7 @@ func documentService(cli *CLI, waitSecs int) (*vespa.Service, error) {
 	return waiter.Service(target, cli.config.cluster())
 }
 
-func printResult(cli *CLI, result util.OperationResult, payloadOnlyOnSuccess bool) error {
+func printResult(cli *CLI, result OperationResult, payloadOnlyOnSuccess bool) error {
 	out := cli.Stdout
 	if !result.Success {
 		out = cli.Stderr
diff --git a/client/go/internal/cli/cmd/document_test.go b/client/go/internal/cli/cmd/document_test.go
index 0b8d5a50615..3cfc66fdad4 100644
--- a/client/go/internal/cli/cmd/document_test.go
+++ b/client/go/internal/cli/cmd/document_test.go
@@ -12,8 +12,8 @@ import (
 	"testing"
 
 	"github.com/stretchr/testify/assert"
+	"github.com/vespa-engine/vespa/client/go/internal/ioutil"
 	"github.com/vespa-engine/vespa/client/go/internal/mock"
-	"github.com/vespa-engine/vespa/client/go/internal/util"
 	"github.com/vespa-engine/vespa/client/go/internal/vespa"
 )
 
@@ -148,7 +148,7 @@ func assertDocumentSend(args []string, expectedOperation string, expectedMethod
 			Fields json.RawMessage `json:"fields"`
 		}
 		assert.Nil(t, json.Unmarshal(data, &expectedPayload))
-		assert.Equal(t, `{"fields":`+string(expectedPayload.Fields)+"}", util.ReaderToString(client.LastRequest.Body))
+		assert.Equal(t, `{"fields":`+string(expectedPayload.Fields)+"}", ioutil.ReaderToString(client.LastRequest.Body))
 	} else {
 		assert.Nil(t, client.LastRequest.Body)
 	}
diff --git a/client/go/internal/cli/cmd/feed.go b/client/go/internal/cli/cmd/feed.go
index 89e13a4673c..69b847547a9 100644
--- a/client/go/internal/cli/cmd/feed.go
+++ b/client/go/internal/cli/cmd/feed.go
@@ -12,7 +12,7 @@ import (
 	"time"
 
 	"github.com/spf13/cobra"
-	"github.com/vespa-engine/vespa/client/go/internal/util"
+	"github.com/vespa-engine/vespa/client/go/internal/httputil"
 	"github.com/vespa-engine/vespa/client/go/internal/vespa/document"
 )
 
@@ -124,7 +124,7 @@ $ cat docs.jsonl | vespa feed -`,
 	return cmd
 }
 
-func createServices(n int, timeout time.Duration, waitSecs int, cli *CLI) ([]util.HTTPClient, string, error) {
+func createServices(n int, timeout time.Duration, waitSecs int, cli *CLI) ([]httputil.Client, string, error) {
 	if n < 1 {
 		return nil, "", fmt.Errorf("need at least one client")
 	}
@@ -132,7 +132,7 @@ func createServices(n int, timeout time.Duration, waitSecs int, cli *CLI) ([]uti
 	if err != nil {
 		return nil, "", err
 	}
-	services := make([]util.HTTPClient, 0, n)
+	services := make([]httputil.Client, 0, n)
 	baseURL := ""
 	waiter := cli.waiter(time.Duration(waitSecs) * time.Second)
 	for i := 0; i < n; i++ {
@@ -144,7 +144,7 @@ func createServices(n int, timeout time.Duration, waitSecs int, cli *CLI) ([]uti
 		// Create a separate HTTP client for each service
 		client := cli.httpClientFactory(timeout)
 		// Feeding should always use HTTP/2
-		util.ForceHTTP2(client, service.TLSOptions.KeyPair, service.TLSOptions.CACertificate, service.TLSOptions.TrustAll)
+		httputil.ForceHTTP2(client, service.TLSOptions.KeyPair, service.TLSOptions.CACertificate, service.TLSOptions.TrustAll)
 		service.SetClient(client)
 		services = append(services, service)
 	}
diff --git a/client/go/internal/cli/cmd/man_test.go b/client/go/internal/cli/cmd/man_test.go
index ad05efcb2a3..ae434624ac7 100644
--- a/client/go/internal/cli/cmd/man_test.go
+++ b/client/go/internal/cli/cmd/man_test.go
@@ -7,7 +7,7 @@ import (
 	"testing"
 
 	"github.com/stretchr/testify/assert"
-	"github.com/vespa-engine/vespa/client/go/internal/util"
+	"github.com/vespa-engine/vespa/client/go/internal/ioutil"
 )
 
 func TestMan(t *testing.T) {
@@ -15,5 +15,5 @@ func TestMan(t *testing.T) {
 	cli, stdout, _ := newTestCLI(t)
 	assert.Nil(t, cli.Run("man", tmpDir))
 	assert.Equal(t, fmt.Sprintf("Success: Man pages written to %s\n", tmpDir), stdout.String())
-	assert.True(t, util.PathExists(filepath.Join(tmpDir, "vespa.1")))
+	assert.True(t, ioutil.Exists(filepath.Join(tmpDir, "vespa.1")))
 }
diff --git a/client/go/internal/cli/cmd/prod.go b/client/go/internal/cli/cmd/prod.go
index ddf2995126a..0912ca31e25 100644
--- a/client/go/internal/cli/cmd/prod.go
+++ b/client/go/internal/cli/cmd/prod.go
@@ -15,7 +15,7 @@ import (
 
 	"github.com/fatih/color"
 	"github.com/spf13/cobra"
-	"github.com/vespa-engine/vespa/client/go/internal/util"
+	"github.com/vespa-engine/vespa/client/go/internal/ioutil"
 	"github.com/vespa-engine/vespa/client/go/internal/vespa"
 	"github.com/vespa-engine/vespa/client/go/internal/vespa/xml"
 )
@@ -187,7 +187,7 @@ $ vespa prod deploy`,
 
 func writeWithBackup(stdout io.Writer, pkg vespa.ApplicationPackage, filename, contents string) error {
 	dst := filepath.Join(pkg.Path, filename)
-	if util.PathExists(dst) {
+	if ioutil.Exists(dst) {
 		data, err := os.ReadFile(dst)
 		if err != nil {
 			return err
@@ -199,7 +199,7 @@ func writeWithBackup(stdout io.Writer, pkg vespa.ApplicationPackage, filename, c
 		renamed := false
 		for i := 1; i <= 1000; i++ {
 			bak := fmt.Sprintf("%s.%d.bak", dst, i)
-			if !util.PathExists(bak) {
+			if !ioutil.Exists(bak) {
 				fmt.Fprintf(stdout, "Backing up existing %s to %s\n", color.YellowString(filename), color.YellowString(bak))
 				if err := os.Rename(dst, bak); err != nil {
 					return err
diff --git a/client/go/internal/cli/cmd/prod_test.go b/client/go/internal/cli/cmd/prod_test.go
index 7f2836125d8..6d8a50124ac 100644
--- a/client/go/internal/cli/cmd/prod_test.go
+++ b/client/go/internal/cli/cmd/prod_test.go
@@ -10,8 +10,8 @@ import (
 	"testing"
 
 	"github.com/stretchr/testify/assert"
+	"github.com/vespa-engine/vespa/client/go/internal/ioutil"
 	"github.com/vespa-engine/vespa/client/go/internal/mock"
-	"github.com/vespa-engine/vespa/client/go/internal/util"
 	"github.com/vespa-engine/vespa/client/go/internal/vespa"
 )
 
@@ -76,8 +76,8 @@ func TestProdInit(t *testing.T) {
 	assert.Contains(t, servicesXML, contentFragment)
 
 	// Backups are created
-	assert.True(t, util.PathExists(deploymentPath+".1.bak"))
-	assert.True(t, util.PathExists(servicesPath+".1.bak"))
+	assert.True(t, ioutil.Exists(deploymentPath+".1.bak"))
+	assert.True(t, ioutil.Exists(servicesPath+".1.bak"))
 }
 
 func readFileString(t *testing.T, filename string) string {
diff --git a/client/go/internal/cli/cmd/query.go b/client/go/internal/cli/cmd/query.go
index bf2272ca981..3e5a60a15df 100644
--- a/client/go/internal/cli/cmd/query.go
+++ b/client/go/internal/cli/cmd/query.go
@@ -16,7 +16,7 @@ import (
 	"github.com/fatih/color"
 	"github.com/spf13/cobra"
 	"github.com/vespa-engine/vespa/client/go/internal/curl"
-	"github.com/vespa-engine/vespa/client/go/internal/util"
+	"github.com/vespa-engine/vespa/client/go/internal/ioutil"
 	"github.com/vespa-engine/vespa/client/go/internal/vespa"
 )
 
@@ -98,11 +98,11 @@ func query(cli *CLI, arguments []string, timeoutSecs, waitSecs int, curl bool) e
 	defer response.Body.Close()
 
 	if response.StatusCode == 200 {
-		log.Print(util.ReaderToJSON(response.Body))
+		log.Print(ioutil.ReaderToJSON(response.Body))
 	} else if response.StatusCode/100 == 4 {
-		return fmt.Errorf("invalid query: %s\n%s", response.Status, util.ReaderToJSON(response.Body))
+		return fmt.Errorf("invalid query: %s\n%s", response.Status, ioutil.ReaderToJSON(response.Body))
 	} else {
-		return fmt.Errorf("%s from container at %s\n%s", response.Status, color.CyanString(url.Host), util.ReaderToJSON(response.Body))
+		return fmt.Errorf("%s from container at %s\n%s", response.Status, color.CyanString(url.Host), ioutil.ReaderToJSON(response.Body))
 	}
 	return nil
 }
diff --git a/client/go/internal/util/operation_result.go b/client/go/internal/cli/cmd/result.go
index 7dc60f92e1d..65b7ec4ca63 100644
--- a/client/go/internal/util/operation_result.go
+++ b/client/go/internal/cli/cmd/result.go
@@ -1,8 +1,4 @@
-// Copyright Vespa.ai. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
-// A struct containing the result of an operation
-// Author: bratseth
-
-package util
+package cmd
 
 type OperationResult struct {
 	Success bool
diff --git a/client/go/internal/cli/cmd/root.go b/client/go/internal/cli/cmd/root.go
index 1f324658b69..383ce7dd28d 100644
--- a/client/go/internal/cli/cmd/root.go
+++ b/client/go/internal/cli/cmd/root.go
@@ -12,6 +12,7 @@ import (
 	"strings"
 	"time"
 
+	"github.com/briandowns/spinner"
 	"github.com/fatih/color"
 	"github.com/mattn/go-colorable"
 	"github.com/mattn/go-isatty"
@@ -20,7 +21,7 @@ import (
 	"github.com/vespa-engine/vespa/client/go/internal/build"
 	"github.com/vespa-engine/vespa/client/go/internal/cli/auth/auth0"
 	"github.com/vespa-engine/vespa/client/go/internal/cli/auth/zts"
-	"github.com/vespa-engine/vespa/client/go/internal/util"
+	"github.com/vespa-engine/vespa/client/go/internal/httputil"
 	"github.com/vespa-engine/vespa/client/go/internal/version"
 	"github.com/vespa-engine/vespa/client/go/internal/vespa"
 )
@@ -58,8 +59,8 @@ type CLI struct {
 	config  *Config
 	version version.Version
 
-	httpClient        util.HTTPClient
-	httpClientFactory func(timeout time.Duration) util.HTTPClient
+	httpClient        httputil.Client
+	httpClientFactory func(timeout time.Duration) httputil.Client
 	auth0Factory      auth0Factory
 	ztsFactory        ztsFactory
 }
@@ -102,9 +103,33 @@ func (c *execSubprocess) Run(name string, args ...string) ([]byte, error) {
 	return exec.Command(name, args...).Output()
 }
 
-type auth0Factory func(httpClient util.HTTPClient, options auth0.Options) (vespa.Authenticator, error)
+type auth0Factory func(httpClient httputil.Client, options auth0.Options) (vespa.Authenticator, error)
 
-type ztsFactory func(httpClient util.HTTPClient, domain, url string) (vespa.Authenticator, error)
+type ztsFactory func(httpClient httputil.Client, domain, url string) (vespa.Authenticator, error)
+
+// newSpinner writes message to writer w and executes function fn. While fn is running a spinning animation will be
+// displayed after message.
+func newSpinner(w io.Writer, message string, fn func() error) error {
+	s := spinner.New(spinner.CharSets[11], 100*time.Millisecond, spinner.WithWriter(w))
+	// Cursor is hidden by default. Hiding cursor requires Stop() to be called to restore cursor (i.e. if the process is
+	// interrupted), however we don't want to bother with a signal handler just for this
+	s.HideCursor = false
+	if err := s.Color("blue", "bold"); err != nil {
+		return err
+	}
+	if !strings.HasSuffix(message, " ") {
+		message += " "
+	}
+	s.Prefix = message
+	s.FinalMSG = "\r" + message + "done\n"
+	s.Start()
+	err := fn()
+	if err != nil {
+		s.FinalMSG = "\r" + message + "failed\n"
+	}
+	s.Stop()
+	return err
+}
 
 // New creates the Vespa CLI, writing output to stdout and stderr, and reading environment variables from environment.
 func New(stdout, stderr io.Writer, environment []string) (*CLI, error) {
@@ -136,7 +161,7 @@ For detailed description of flags and configuration, see 'vespa help config'.
 	if err != nil {
 		return nil, err
 	}
-	httpClientFactory := util.CreateClient
+	httpClientFactory := httputil.NewClient
 	cli := CLI{
 		Environment: env,
 		Stdin:       os.Stdin,
@@ -152,10 +177,10 @@ For detailed description of flags and configuration, see 'vespa help config'.
 
 		httpClient:        httpClientFactory(time.Second * 10),
 		httpClientFactory: httpClientFactory,
-		auth0Factory: func(httpClient util.HTTPClient, options auth0.Options) (vespa.Authenticator, error) {
+		auth0Factory: func(httpClient httputil.Client, options auth0.Options) (vespa.Authenticator, error) {
 			return auth0.NewClient(httpClient, options)
 		},
-		ztsFactory: func(httpClient util.HTTPClient, domain, url string) (vespa.Authenticator, error) {
+		ztsFactory: func(httpClient httputil.Client, domain, url string) (vespa.Authenticator, error) {
 			return zts.NewClient(httpClient, domain, url)
 		},
 	}
@@ -239,7 +264,7 @@ func (c *CLI) configureSpinner() {
 			return fn()
 		}
 	} else {
-		c.spinner = util.Spinner
+		c.spinner = newSpinner
 	}
 }
 
diff --git a/client/go/internal/cli/cmd/test.go b/client/go/internal/cli/cmd/test.go
index 376611767d9..3bc78fc91c8 100644
--- a/client/go/internal/cli/cmd/test.go
+++ b/client/go/internal/cli/cmd/test.go
@@ -21,7 +21,8 @@ import (
 
 	"github.com/fatih/color"
 	"github.com/spf13/cobra"
-	"github.com/vespa-engine/vespa/client/go/internal/util"
+	"github.com/vespa-engine/vespa/client/go/internal/httputil"
+	"github.com/vespa-engine/vespa/client/go/internal/ioutil"
 	"github.com/vespa-engine/vespa/client/go/internal/vespa"
 )
 
@@ -277,7 +278,7 @@ func verify(step step, defaultCluster string, defaultParameters map[string]strin
 
 	var response *http.Response
 	if externalEndpoint {
-		util.ConfigureTLS(context.cli.httpClient, []tls.Certificate{}, nil, false)
+		httputil.ConfigureTLS(context.cli.httpClient, []tls.Certificate{}, nil, false)
 		response, err = context.cli.httpClient.Do(request, 60*time.Second)
 	} else {
 		response, err = service.Do(request, 600*time.Second) // Vespa should provide a response within the given request timeout
@@ -294,7 +295,7 @@ func verify(step step, defaultCluster string, defaultParameters map[string]strin
 				color.RedString(strconv.Itoa(response.StatusCode)),
 				color.CyanString(method),
 				color.CyanString(requestUrl.String()),
-				util.ReaderToJSON(response.Body)), nil
+				ioutil.ReaderToJSON(response.Body)), nil
 	}
 
 	if responseBodySpec == nil {
diff --git a/client/go/internal/cli/cmd/test_test.go b/client/go/internal/cli/cmd/test_test.go
index 1888db017d4..728e8c29691 100644
--- a/client/go/internal/cli/cmd/test_test.go
+++ b/client/go/internal/cli/cmd/test_test.go
@@ -15,8 +15,8 @@ import (
 
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
+	"github.com/vespa-engine/vespa/client/go/internal/ioutil"
 	"github.com/vespa-engine/vespa/client/go/internal/mock"
-	"github.com/vespa-engine/vespa/client/go/internal/util"
 	"github.com/vespa-engine/vespa/client/go/internal/vespa"
 )
 
@@ -205,6 +205,6 @@ func assertRequests(requests []*http.Request, client *mock.HTTPClient, t *testin
 		if actualBody == nil {
 			actualBody = io.NopCloser(strings.NewReader(""))
 		}
-		assert.Equal(t, util.ReaderToJSON(want.Body), util.ReaderToJSON(actualBody))
+		assert.Equal(t, ioutil.ReaderToJSON(want.Body), ioutil.ReaderToJSON(actualBody))
 	}
 }
diff --git a/client/go/internal/cli/cmd/testutil_test.go b/client/go/internal/cli/cmd/testutil_test.go
index 89f40035f6a..dbeb281a4a8 100644
--- a/client/go/internal/cli/cmd/testutil_test.go
+++ b/client/go/internal/cli/cmd/testutil_test.go
@@ -11,8 +11,8 @@ import (
 	"time"
 
 	"github.com/vespa-engine/vespa/client/go/internal/cli/auth/auth0"
+	"github.com/vespa-engine/vespa/client/go/internal/httputil"
 	"github.com/vespa-engine/vespa/client/go/internal/mock"
-	"github.com/vespa-engine/vespa/client/go/internal/util"
 	"github.com/vespa-engine/vespa/client/go/internal/vespa"
 )
 
@@ -31,13 +31,13 @@ func newTestCLI(t *testing.T, envVars ...string) (*CLI, *bytes.Buffer, *bytes.Bu
 		t.Fatal(err)
 	}
 	httpClient := &mock.HTTPClient{}
-	cli.httpClientFactory = func(timeout time.Duration) util.HTTPClient { return httpClient }
+	cli.httpClientFactory = func(timeout time.Duration) httputil.Client { return httpClient }
 	cli.httpClient = httpClient
 	cli.exec = &mock.Exec{}
-	cli.auth0Factory = func(httpClient util.HTTPClient, options auth0.Options) (vespa.Authenticator, error) {
+	cli.auth0Factory = func(httpClient httputil.Client, options auth0.Options) (vespa.Authenticator, error) {
 		return &mockAuthenticator{}, nil
 	}
-	cli.ztsFactory = func(httpClient util.HTTPClient, domain, url string) (vespa.Authenticator, error) {
+	cli.ztsFactory = func(httpClient httputil.Client, domain, url string) (vespa.Authenticator, error) {
 		return &mockAuthenticator{}, nil
 	}
 	return cli, &stdout, &stderr
diff --git a/client/go/internal/cli/cmd/visit.go b/client/go/internal/cli/cmd/visit.go
index f6e2f64e534..963833337c2 100644
--- a/client/go/internal/cli/cmd/visit.go
+++ b/client/go/internal/cli/cmd/visit.go
@@ -16,7 +16,7 @@ import (
 	"time"
 
 	"github.com/spf13/cobra"
-	"github.com/vespa-engine/vespa/client/go/internal/util"
+	"github.com/vespa-engine/vespa/client/go/internal/ioutil"
 	"github.com/vespa-engine/vespa/client/go/internal/vespa"
 )
 
@@ -157,26 +157,26 @@ func getEpoch(timeStamp string) (int64, error) {
 	return t, nil
 }
 
-func checkArguments(vArgs visitArgs) (res util.OperationResult) {
+func checkArguments(vArgs visitArgs) (res OperationResult) {
 	if vArgs.slices > 0 || vArgs.sliceId > -1 {
 		if !(vArgs.slices > 0 && vArgs.sliceId > -1) {
-			return util.Failure("Both 'slices' and 'slice-id' must be set")
+			return Failure("Both 'slices' and 'slice-id' must be set")
 		}
 		if vArgs.sliceId >= vArgs.slices {
-			return util.Failure("The 'slice-id' must be in range [0, slices)")
+			return Failure("The 'slice-id' must be in range [0, slices)")
 		}
 	}
 	// to and from will support RFC3339 format soon, add more validation then
 	if vArgs.from != "" {
 		_, err := getEpoch(vArgs.from)
 		if err != nil {
-			return util.Failure("Invalid 'from' argument: '" + vArgs.from + "': " + err.Error())
+			return Failure("Invalid 'from' argument: '" + vArgs.from + "': " + err.Error())
 		}
 	}
 	if vArgs.to != "" {
 		_, err := getEpoch(vArgs.to)
 		if err != nil {
-			return util.Failure("Invalid 'to' argument: '" + vArgs.to + "': " + err.Error())
+			return Failure("Invalid 'to' argument: '" + vArgs.to + "': " + err.Error())
 		}
 	}
 	for _, b := range vArgs.bucketSpaces {
@@ -186,10 +186,10 @@ func checkArguments(vArgs visitArgs) (res util.OperationResult) {
 			"global":
 			// Do nothing
 		default:
-			return util.Failure("Invalid 'bucket-space' argument '" + b + "', must be 'default' or 'global'")
+			return Failure("Invalid 'bucket-space' argument '" + b + "', must be 'default' or 'global'")
 		}
 	}
-	return util.Success("")
+	return Success("")
 }
 
 type HandlersInfo struct {
@@ -208,11 +208,11 @@ func parseHandlersOutput(r io.Reader) (*HandlersInfo, error) {
 	return &handlersInfo, err
 }
 
-func probeHandler(service *vespa.Service, cli *CLI) (res util.OperationResult) {
+func probeHandler(service *vespa.Service, cli *CLI) (res OperationResult) {
 	urlPath := service.BaseURL + "/"
 	url, urlParseError := url.Parse(urlPath)
 	if urlParseError != nil {
-		return util.Failure("Invalid request path: '" + urlPath + "': " + urlParseError.Error())
+		return Failure("Invalid request path: '" + urlPath + "': " + urlParseError.Error())
 	}
 	request := &http.Request{
 		URL:    url,
@@ -221,20 +221,20 @@ func probeHandler(service *vespa.Service, cli *CLI) (res util.OperationResult) {
 	timeout := time.Duration(90) * time.Second
 	response, err := service.Do(request, timeout)
 	if err != nil {
-		return util.Failure("Request failed: " + err.Error())
+		return Failure("Request failed: " + err.Error())
 	}
 	defer response.Body.Close()
 	if response.StatusCode == 200 {
 		handlersInfo, err := parseHandlersOutput(response.Body)
 		if err != nil || len(handlersInfo.Handlers) == 0 {
 			cli.printWarning("Could not parse JSON response from"+urlPath, err.Error())
-			return util.Failure("Bad endpoint")
+			return Failure("Bad endpoint")
 		}
 		for _, h := range handlersInfo.Handlers {
 			if strings.HasSuffix(h.HandlerClass, "DocumentV1ApiHandler") {
 				for _, binding := range h.ServerBindings {
 					if strings.Contains(binding, "/document/v1/") {
-						return util.Success("handler OK")
+						return Success("handler OK")
 					}
 				}
 				w := fmt.Sprintf("expected /document/v1/ binding, but got: %v", h.ServerBindings)
@@ -242,13 +242,13 @@ func probeHandler(service *vespa.Service, cli *CLI) (res util.OperationResult) {
 			}
 		}
 		cli.printWarning("Missing /document/v1/ API; add <document-api /> to the container cluster declaration in services.xml")
-		return util.Failure("Missing /document/v1 API")
+		return Failure("Missing /document/v1 API")
 	} else {
-		return util.FailureWithPayload(service.Description()+" at "+request.URL.Host+": "+response.Status, util.ReaderToJSON(response.Body))
+		return FailureWithPayload(service.Description()+" at "+request.URL.Host+": "+response.Status, ioutil.ReaderToJSON(response.Body))
 	}
 }
 
-func visitClusters(vArgs *visitArgs, service *vespa.Service) (res util.OperationResult) {
+func visitClusters(vArgs *visitArgs, service *vespa.Service) (res OperationResult) {
 	clusters := []string{
 		vArgs.contentCluster,
 	}
@@ -294,7 +294,7 @@ func probeVisit(vArgs *visitArgs, service *vespa.Service) []string {
 	return clusters
 }
 
-func runVisit(vArgs *visitArgs, service *vespa.Service) (res util.OperationResult) {
+func runVisit(vArgs *visitArgs, service *vespa.Service) (res OperationResult) {
 	vArgs.debugPrint(fmt.Sprintf("trying to visit: '%s'", vArgs.contentCluster))
 	var totalDocuments int = 0
 	var continuationToken string
@@ -340,7 +340,7 @@ func quoteArgForUrl(arg string) string {
 	return buf.String()
 }
 
-func runOneVisit(vArgs *visitArgs, service *vespa.Service, contToken string) (*VespaVisitOutput, util.OperationResult) {
+func runOneVisit(vArgs *visitArgs, service *vespa.Service, contToken string) (*VespaVisitOutput, OperationResult) {
 	urlPath := service.BaseURL + "/document/v1/?cluster=" + quoteArgForUrl(vArgs.contentCluster)
 	if vArgs.fieldSet != "" {
 		urlPath = urlPath + "&fieldSet=" + quoteArgForUrl(vArgs.fieldSet)
@@ -370,7 +370,7 @@ func runOneVisit(vArgs *visitArgs, service *vespa.Service, contToken string) (*V
 	}
 	url, urlParseError := url.Parse(urlPath)
 	if urlParseError != nil {
-		return nil, util.Failure("Invalid request path: '" + urlPath + "': " + urlParseError.Error())
+		return nil, Failure("Invalid request path: '" + urlPath + "': " + urlParseError.Error())
 	}
 	request := &http.Request{
 		URL:    url,
@@ -379,7 +379,7 @@ func runOneVisit(vArgs *visitArgs, service *vespa.Service, contToken string) (*V
 	timeout := time.Duration(900) * time.Second
 	response, err := service.Do(request, timeout)
 	if err != nil {
-		return nil, util.Failure("Request failed: " + err.Error())
+		return nil, Failure("Request failed: " + err.Error())
 	}
 	defer response.Body.Close()
 	vvo, err := parseVisitOutput(response.Body)
@@ -390,16 +390,16 @@ func runOneVisit(vArgs *visitArgs, service *vespa.Service, contToken string) (*V
 				vArgs.cli.printWarning(fmt.Sprintf("Inconsistent contents from: %v", url))
 				vArgs.cli.printWarning(fmt.Sprintf("claimed count: %d", vvo.DocumentCount))
 				vArgs.cli.printWarning(fmt.Sprintf("document blobs: %d", len(vvo.Documents)))
-				return nil, util.Failure("Inconsistent contents from document API")
+				return nil, Failure("Inconsistent contents from document API")
 			}
-			return vvo, util.Success("visited " + vArgs.contentCluster)
+			return vvo, Success("visited " + vArgs.contentCluster)
 		} else {
-			return nil, util.Failure("error reading response: " + err.Error())
+			return nil, Failure("error reading response: " + err.Error())
 		}
 	} else if response.StatusCode/100 == 4 {
-		return vvo, util.FailureWithPayload("Invalid document operation: "+response.Status, util.ReaderToJSON(response.Body))
+		return vvo, FailureWithPayload("Invalid document operation: "+response.Status, ioutil.ReaderToJSON(response.Body))
 	} else {
-		return vvo, util.FailureWithPayload(service.Description()+" at "+request.URL.Host+": "+response.Status, util.ReaderToJSON(response.Body))
+		return vvo, FailureWithPayload(service.Description()+" at "+request.URL.Host+": "+response.Status, ioutil.ReaderToJSON(response.Body))
 	}
 }
 
diff --git a/client/go/internal/util/http.go b/client/go/internal/httputil/httputil.go
index a7a9de5b8e4..e1e27de5523 100644
--- a/client/go/internal/util/http.go
+++ b/client/go/internal/httputil/httputil.go
@@ -1,5 +1,5 @@
 // Copyright Vespa.ai. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
-package util
+package httputil
 
 import (
 	"context"
@@ -14,15 +14,16 @@ import (
 	"golang.org/x/net/http2"
 )
 
-type HTTPClient interface {
+// Client represents a HTTP client usable by the Vespa CLI.
+type Client interface {
 	Do(request *http.Request, timeout time.Duration) (response *http.Response, error error)
 }
 
-type defaultHTTPClient struct {
+type defaultClient struct {
 	client *http.Client
 }
 
-func (c *defaultHTTPClient) Do(request *http.Request, timeout time.Duration) (response *http.Response, error error) {
+func (c *defaultClient) Do(request *http.Request, timeout time.Duration) (response *http.Response, error error) {
 	if c.client.Timeout != timeout { // Set wanted timeout
 		c.client.Timeout = timeout
 	}
@@ -33,8 +34,10 @@ func (c *defaultHTTPClient) Do(request *http.Request, timeout time.Duration) (re
 	return c.client.Do(request)
 }
 
-func ConfigureTLS(client HTTPClient, certificates []tls.Certificate, caCertificate []byte, trustAll bool) {
-	c, ok := client.(*defaultHTTPClient)
+// ConfigureTLS configures the given client with given certificates and caCertificate. If trustAll is true, the client
+// will skip verification of the certificate chain.
+func ConfigureTLS(client Client, certificates []tls.Certificate, caCertificate []byte, trustAll bool) {
+	c, ok := client.(*defaultClient)
 	if !ok {
 		return
 	}
@@ -60,8 +63,10 @@ func ConfigureTLS(client HTTPClient, certificates []tls.Certificate, caCertifica
 	}
 }
 
-func ForceHTTP2(client HTTPClient, certificates []tls.Certificate, caCertificate []byte, trustAll bool) {
-	c, ok := client.(*defaultHTTPClient)
+// ForceHTTP2 configures the given client exclusively with a HTTP/2 transport. The other options are passed to
+// ConfigureTLS. If certificates is nil, the client will be configured with H2C (HTTP/2 over clear-text).
+func ForceHTTP2(client Client, certificates []tls.Certificate, caCertificate []byte, trustAll bool) {
+	c, ok := client.(*defaultClient)
 	if !ok {
 		return
 	}
@@ -85,8 +90,9 @@ func ForceHTTP2(client HTTPClient, certificates []tls.Certificate, caCertificate
 	ConfigureTLS(client, certificates, caCertificate, trustAll)
 }
 
-func CreateClient(timeout time.Duration) HTTPClient {
-	return &defaultHTTPClient{
+// NewClients creates a new HTTP client the given default timeout.
+func NewClient(timeout time.Duration) Client {
+	return &defaultClient{
 		client: &http.Client{
 			Timeout:   timeout,
 			Transport: http.DefaultTransport,
diff --git a/client/go/internal/util/io.go b/client/go/internal/ioutil/ioutil.go
index 9e755737035..d3a33698d13 100644
--- a/client/go/internal/util/io.go
+++ b/client/go/internal/ioutil/ioutil.go
@@ -2,7 +2,7 @@
 // File utilities.
 // Author: bratseth
 
-package util
+package ioutil
 
 import (
 	"bytes"
@@ -14,26 +14,26 @@ import (
 	"strings"
 )
 
-// Returns true if the given path exists
-func PathExists(path string) bool {
+// Exists returns true if the given path exists.
+func Exists(path string) bool {
 	info, err := os.Stat(path)
 	return !errors.Is(err, os.ErrNotExist) && info != nil
 }
 
-// Returns true if the given path points to an existing directory
-func IsDirectory(path string) bool {
+// IsDir returns true if the given path points to an existing directory.
+func IsDir(path string) bool {
 	info, err := os.Stat(path)
 	return !errors.Is(err, os.ErrNotExist) && info != nil && info.IsDir()
 }
 
-// Returns true if the given path points to an existing file
-func IsRegularFile(path string) bool {
+// IsFile returns true if the given path points to an existing regular file.
+func IsFile(path string) bool {
 	info, err := os.Stat(path)
 	return !errors.Is(err, os.ErrNotExist) && info != nil && info.Mode().IsRegular()
 }
 
-// Returns true if the given path points to an executable
-func IsExecutableFile(path string) bool {
+// IsExecutable returns true if the given path points to an executable file.
+func IsExecutable(path string) bool {
 	info, err := os.Stat(path)
 	return !errors.Is(err, os.ErrNotExist) &&
 		info != nil &&
@@ -41,21 +41,21 @@ func IsExecutableFile(path string) bool {
 		((int(info.Mode()) & 0111) == 0111)
 }
 
-// Returns the content of a reader as a string
+// ReaderToString Returns the content of reader as a string. Read errors are ignored.
 func ReaderToString(reader io.Reader) string {
 	var buffer strings.Builder
 	io.Copy(&buffer, reader)
 	return buffer.String()
 }
 
-// Returns the content of a reader as a byte array
+// ReaderToBytes returns the content of a reader as a byte array. Read errors are ignored.
 func ReaderToBytes(reader io.Reader) []byte {
 	var buffer bytes.Buffer
 	buffer.ReadFrom(reader)
 	return buffer.Bytes()
 }
 
-// Returns the contents of reader as indented JSON
+// ReaderToJSON returns the contents of reader as indented JSON. Read errors are ignored.
 func ReaderToJSON(reader io.Reader) string {
 	bodyBytes, _ := io.ReadAll(reader)
 	var prettyJSON bytes.Buffer
diff --git a/client/go/internal/util/io_test.go b/client/go/internal/ioutil/ioutil_test.go
index 0b2ad0f081b..907132c9eaa 100644
--- a/client/go/internal/util/io_test.go
+++ b/client/go/internal/ioutil/ioutil_test.go
@@ -1,5 +1,5 @@
 // Copyright Vespa.ai. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
-package util
+package ioutil
 
 import (
 	"os"
@@ -9,46 +9,46 @@ import (
 )
 
 func TestPathExists(t *testing.T) {
-	assert.Equal(t, true, PathExists("io.go"))
-	assert.Equal(t, false, PathExists("nosuchthing.go"))
+	assert.Equal(t, true, Exists("ioutil.go"))
+	assert.Equal(t, false, Exists("nosuchthing.go"))
 
 	tmpDir := t.TempDir()
 	err := os.MkdirAll(tmpDir+"/no", 0755)
 	assert.Nil(t, err)
 	err = os.MkdirAll(tmpDir+"/no/such", 0)
 	assert.Nil(t, err)
-	assert.Equal(t, false, PathExists(tmpDir+"/no/such/thing.go"))
+	assert.Equal(t, false, Exists(tmpDir+"/no/such/thing.go"))
 }
 
 func TestIsDir(t *testing.T) {
 	tmpDir := t.TempDir()
 	err := os.MkdirAll(tmpDir+"/no", 0755)
 	assert.Nil(t, err)
-	assert.Equal(t, true, IsDirectory(tmpDir+"/no"))
+	assert.Equal(t, true, IsDir(tmpDir+"/no"))
 	err = os.MkdirAll(tmpDir+"/no/such", 0)
 	assert.Nil(t, err)
-	assert.Equal(t, true, IsDirectory(tmpDir+"/no/such"))
-	assert.Equal(t, false, IsDirectory(tmpDir+"/no/such/thing.go"))
+	assert.Equal(t, true, IsDir(tmpDir+"/no/such"))
+	assert.Equal(t, false, IsDir(tmpDir+"/no/such/thing.go"))
 }
 
 func TestIsRegularFile(t *testing.T) {
-	assert.Equal(t, true, IsRegularFile("io.go"))
-	assert.Equal(t, false, IsRegularFile("."))
+	assert.Equal(t, true, IsFile("ioutil.go"))
+	assert.Equal(t, false, IsFile("."))
 	tmpDir := t.TempDir()
 	err := os.MkdirAll(tmpDir+"/no", 0755)
 	assert.Nil(t, err)
 	err = os.MkdirAll(tmpDir+"/no/such", 0)
 	assert.Nil(t, err)
-	assert.Equal(t, false, IsRegularFile(tmpDir+"/no/such/thing.go"))
+	assert.Equal(t, false, IsFile(tmpDir+"/no/such/thing.go"))
 }
 
 func TestIsExecutableFile(t *testing.T) {
-	assert.Equal(t, false, IsExecutableFile("io.go"))
-	assert.Equal(t, false, IsExecutableFile("nosuchthing.go"))
+	assert.Equal(t, false, IsExecutable("io.go"))
+	assert.Equal(t, false, IsExecutable("nosuchthing.go"))
 	tmpDir := t.TempDir()
 	err := os.WriteFile(tmpDir+"/run.sh", []byte("#!/bin/sh\necho foo\n"), 0755)
 	assert.Nil(t, err)
-	assert.Equal(t, true, IsExecutableFile(tmpDir+"/run.sh"))
+	assert.Equal(t, true, IsExecutable(tmpDir+"/run.sh"))
 	/* unix only:
 	out, err := BackTicksWithStderr.Run(tmpDir + "/run.sh")
 	assert.Nil(t, err)
diff --git a/client/go/internal/util/array_list.go b/client/go/internal/list/array_list.go
index 0e768b5617f..07427074089 100644
--- a/client/go/internal/util/array_list.go
+++ b/client/go/internal/list/array_list.go
@@ -1,8 +1,7 @@
 // Copyright Vespa.ai. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
 // Author: arnej
 
-// generic utilities
-package util
+package list
 
 type ArrayList[E comparable] []E
 
diff --git a/client/go/internal/util/array_list_test.go b/client/go/internal/list/array_list_test.go
index d8a3fa88b5c..f31a94966c5 100644
--- a/client/go/internal/util/array_list_test.go
+++ b/client/go/internal/list/array_list_test.go
@@ -1,5 +1,6 @@
 // Copyright Vespa.ai. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
-package util
+
+package list
 
 import (
 	"testing"
diff --git a/client/go/internal/mock/http.go b/client/go/internal/mock/http.go
index c01811c4630..06e143ab80d 100644
--- a/client/go/internal/mock/http.go
+++ b/client/go/internal/mock/http.go
@@ -9,7 +9,7 @@ import (
 	"strconv"
 	"time"
 
-	"github.com/vespa-engine/vespa/client/go/internal/util"
+	"github.com/vespa-engine/vespa/client/go/internal/httputil"
 )
 
 type HTTPClient struct {
@@ -95,4 +95,4 @@ func (c *HTTPClient) Do(request *http.Request, timeout time.Duration) (*http.Res
 		nil
 }
 
-func (c *HTTPClient) Clone() util.HTTPClient { return c }
+func (c *HTTPClient) Clone() httputil.Client { return c }
diff --git a/client/go/internal/util/execvp.go b/client/go/internal/osutil/execvp.go
index 38514696365..331b8166428 100644
--- a/client/go/internal/util/execvp.go
+++ b/client/go/internal/osutil/execvp.go
@@ -3,7 +3,7 @@
 
 //go:build !windows
 
-package util
+package osutil
 
 import (
 	"fmt"
@@ -12,6 +12,7 @@ import (
 
 	"github.com/vespa-engine/vespa/client/go/internal/admin/envvars"
 	"github.com/vespa-engine/vespa/client/go/internal/admin/trace"
+	"github.com/vespa-engine/vespa/client/go/internal/ioutil"
 	"golang.org/x/sys/unix"
 )
 
@@ -22,7 +23,7 @@ func findInPath(prog string) string {
 	path := strings.Split(os.Getenv(envvars.PATH), ":")
 	for _, dir := range path {
 		fn := dir + "/" + prog
-		if IsExecutableFile(fn) {
+		if ioutil.IsExecutable(fn) {
 			return fn
 		}
 	}
diff --git a/client/go/internal/util/execvp_windows.go b/client/go/internal/osutil/execvp_windows.go
index d01eda589ff..0e8e7a4a673 100644
--- a/client/go/internal/util/execvp_windows.go
+++ b/client/go/internal/osutil/execvp_windows.go
@@ -3,7 +3,7 @@
 
 //go:build windows
 
-package util
+package osutil
 
 import (
 	"fmt"
diff --git a/client/go/internal/util/fix_fs.go b/client/go/internal/osutil/fix_fs.go
index 12d49462e07..837624cc05b 100644
--- a/client/go/internal/util/fix_fs.go
+++ b/client/go/internal/osutil/fix_fs.go
@@ -1,7 +1,7 @@
 // Copyright Vespa.ai. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
 // Author: arnej
 
-package util
+package osutil
 
 import (
 	"errors"
@@ -149,5 +149,5 @@ func (spec *FixSpec) complainAndExit(got error, fn string, wanted os.FileMode) {
 	out, _ := BackTicksWithStderr.Run("stat", "--", fn)
 	trace.Warning(out)
 	trace.Warning("this is a fatal error!")
-	JustExitWith(got)
+	ExitErr(got)
 }
diff --git a/client/go/internal/util/fix_fs_test.go b/client/go/internal/osutil/fix_fs_test.go
index 0ecf2e06535..792986d7996 100644
--- a/client/go/internal/util/fix_fs_test.go
+++ b/client/go/internal/osutil/fix_fs_test.go
@@ -1,5 +1,5 @@
 // Copyright Vespa.ai. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
-package util
+package osutil
 
 import (
 	"os"
@@ -10,6 +10,7 @@ import (
 
 	"github.com/stretchr/testify/assert"
 	"github.com/vespa-engine/vespa/client/go/internal/admin/trace"
+	"github.com/vespa-engine/vespa/client/go/internal/ioutil"
 )
 
 func setup(t *testing.T) string {
@@ -36,15 +37,15 @@ func testFixSpec(t *testing.T, spec FixSpec) {
 	spec.FixFile(tmpDir + "/a/f3")
 	spec.FixFile(tmpDir + "/b/f4")
 	spec.FixFile(tmpDir + "/a/bad/f5")
-	assert.Equal(t, true, IsDirectory(tmpDir+"/a"))
-	assert.Equal(t, true, IsDirectory(tmpDir+"/b"))
-	assert.Equal(t, true, IsDirectory(tmpDir+"/a/bad"))
-	assert.Equal(t, true, IsDirectory(tmpDir+"/a/bad/ok"))
-	assert.Equal(t, true, IsRegularFile(tmpDir+"/a/f1"))
-	assert.Equal(t, true, IsRegularFile(tmpDir+"/a/f2"))
-	assert.Equal(t, false, IsRegularFile(tmpDir+"/a/f3"))
-	assert.Equal(t, false, IsRegularFile(tmpDir+"/b/f4"))
-	assert.Equal(t, false, IsRegularFile(tmpDir+"/a/bad/f5"))
+	assert.Equal(t, true, ioutil.IsDir(tmpDir+"/a"))
+	assert.Equal(t, true, ioutil.IsDir(tmpDir+"/b"))
+	assert.Equal(t, true, ioutil.IsDir(tmpDir+"/a/bad"))
+	assert.Equal(t, true, ioutil.IsDir(tmpDir+"/a/bad/ok"))
+	assert.Equal(t, true, ioutil.IsFile(tmpDir+"/a/f1"))
+	assert.Equal(t, true, ioutil.IsFile(tmpDir+"/a/f2"))
+	assert.Equal(t, false, ioutil.IsFile(tmpDir+"/a/f3"))
+	assert.Equal(t, false, ioutil.IsFile(tmpDir+"/b/f4"))
+	assert.Equal(t, false, ioutil.IsFile(tmpDir+"/a/bad/f5"))
 
 	info, err := os.Stat(tmpDir + "/a")
 	assert.Nil(t, err)
@@ -118,7 +119,7 @@ func TestSuperUserOnly(t *testing.T) {
 
 func expectSimplePanic() {
 	if r := recover(); r != nil {
-		if jee, ok := r.(*JustExitError); ok {
+		if jee, ok := r.(*ExitError); ok {
 			trace.Trace("got as expected:", jee)
 			return
 		}
diff --git a/client/go/internal/util/just_exit.go b/client/go/internal/osutil/just_exit.go
index ad07f451c9c..5ad85ec9ceb 100644
--- a/client/go/internal/util/just_exit.go
+++ b/client/go/internal/osutil/just_exit.go
@@ -1,7 +1,7 @@
 // Copyright Vespa.ai. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
 // Author: arnej
 
-package util
+package osutil
 
 import (
 	"fmt"
@@ -9,12 +9,12 @@ import (
 	"github.com/vespa-engine/vespa/client/go/internal/admin/trace"
 )
 
-type JustExitError struct {
+type ExitError struct {
 	err error
 	msg string
 }
 
-func (j *JustExitError) String() string {
+func (j *ExitError) String() string {
 	if j.err != nil {
 		if j.msg == "" {
 			return j.err.Error()
@@ -27,22 +27,22 @@ func (j *JustExitError) String() string {
 	return j.msg
 }
 
-func (j *JustExitError) Error() string {
+func (j *ExitError) Error() string {
 	return j.String()
 }
 
-func JustExitMsg(message string) {
+func ExitMsg(message string) {
 	trace.Trace("just exit with message")
-	j := JustExitError{
+	j := ExitError{
 		err: nil,
 		msg: message,
 	}
 	panic(&j)
 }
 
-func JustExitWith(e error) {
+func ExitErr(e error) {
 	trace.Trace("just exit with error")
-	j := JustExitError{
+	j := ExitError{
 		err: e,
 		msg: "",
 	}
diff --git a/client/go/internal/util/run_cmd.go b/client/go/internal/osutil/run_cmd.go
index cc40f86154c..ca0d621f9f9 100644
--- a/client/go/internal/util/run_cmd.go
+++ b/client/go/internal/osutil/run_cmd.go
@@ -1,7 +1,7 @@
 // Copyright Vespa.ai. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
 // Author: arnej
 
-package util
+package osutil
 
 import (
 	"bytes"
diff --git a/client/go/internal/util/setrlimit.go b/client/go/internal/osutil/setrlimit.go
index 1a96d260fcb..6bc6d68af3e 100644
--- a/client/go/internal/util/setrlimit.go
+++ b/client/go/internal/osutil/setrlimit.go
@@ -2,7 +2,7 @@
 
 //go:build !windows
 
-package util
+package osutil
 
 import (
 	"os"
diff --git a/client/go/internal/util/setrlimit_windows.go b/client/go/internal/osutil/setrlimit_windows.go
index f2993c7af13..e61233ba9e6 100644
--- a/client/go/internal/util/setrlimit_windows.go
+++ b/client/go/internal/osutil/setrlimit_windows.go
@@ -2,7 +2,7 @@
 
 //go:build windows
 
-package util
+package osutil
 
 type ResourceId int
 
diff --git a/client/go/internal/util/tune_logctl.go b/client/go/internal/osutil/tune_logctl.go
index b66c14c2d65..f68259170c7 100644
--- a/client/go/internal/util/tune_logctl.go
+++ b/client/go/internal/osutil/tune_logctl.go
@@ -1,7 +1,7 @@
 // Copyright Vespa.ai. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
 // Author: arnej
 
-package util
+package osutil
 
 func TuneLogging(serviceName, component, settings string) bool {
 	arg := serviceName
diff --git a/client/go/internal/util/tuning.go b/client/go/internal/osutil/tuning.go
index cca314247ab..8e9b894e8ae 100644
--- a/client/go/internal/util/tuning.go
+++ b/client/go/internal/osutil/tuning.go
@@ -1,7 +1,7 @@
 // Copyright Vespa.ai. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
 // Author: arnej
 
-package util
+package osutil
 
 import (
 	"os"
diff --git a/client/go/internal/util/md5.go b/client/go/internal/util/md5.go
deleted file mode 100644
index 6a98b49c472..00000000000
--- a/client/go/internal/util/md5.go
+++ /dev/null
@@ -1,17 +0,0 @@
-// Copyright Vespa.ai. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
-// Author: arnej
-
-package util
-
-import (
-	"crypto/md5"
-	"fmt"
-	"io"
-)
-
-func Md5Hex(text string) string {
-	hasher := md5.New()
-	io.WriteString(hasher, text)
-	hash := hasher.Sum(nil)
-	return fmt.Sprintf("%x", hash)
-}
diff --git a/client/go/internal/util/spinner.go b/client/go/internal/util/spinner.go
deleted file mode 100644
index 323a5fffe12..00000000000
--- a/client/go/internal/util/spinner.go
+++ /dev/null
@@ -1,35 +0,0 @@
-// Copyright Vespa.ai. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
-
-package util
-
-import (
-	"io"
-	"strings"
-	"time"
-
-	"github.com/briandowns/spinner"
-)
-
-// Spinner writes message to writer w and executes function fn. While fn is running a spinning animation will be
-// displayed after message.
-func Spinner(w io.Writer, message string, fn func() error) error {
-	s := spinner.New(spinner.CharSets[11], 100*time.Millisecond, spinner.WithWriter(w))
-	// Cursor is hidden by default. Hiding cursor requires Stop() to be called to restore cursor (i.e. if the process is
-	// interrupted), however we don't want to bother with a signal handler just for this
-	s.HideCursor = false
-	if err := s.Color("blue", "bold"); err != nil {
-		return err
-	}
-	if !strings.HasSuffix(message, " ") {
-		message += " "
-	}
-	s.Prefix = message
-	s.FinalMSG = "\r" + message + "done\n"
-	s.Start()
-	err := fn()
-	if err != nil {
-		s.FinalMSG = "\r" + message + "failed\n"
-	}
-	s.Stop()
-	return err
-}
diff --git a/client/go/internal/version/version.go b/client/go/internal/version/version.go
index 1b27d01ea83..513c808a582 100644
--- a/client/go/internal/version/version.go
+++ b/client/go/internal/version/version.go
@@ -5,8 +5,6 @@ import (
 	"fmt"
 	"strconv"
 	"strings"
-
-	"github.com/vespa-engine/vespa/client/go/internal/util"
 )
 
 // Version represents a semantic version number.
@@ -74,7 +72,7 @@ func (v1 Version) Less(v2 Version) bool { return v1.Compare(v2) < 0 }
 func MustParse(s string) Version {
 	v, err := Parse(s)
 	if err != nil {
-		util.JustExitWith(err)
+		panic(err)
 	}
 	return v
 }
diff --git a/client/go/internal/vespa/application.go b/client/go/internal/vespa/application.go
index 6d28b24100f..5d1ab610e38 100644
--- a/client/go/internal/vespa/application.go
+++ b/client/go/internal/vespa/application.go
@@ -10,7 +10,7 @@ import (
 	"path/filepath"
 	"strings"
 
-	"github.com/vespa-engine/vespa/client/go/internal/util"
+	"github.com/vespa-engine/vespa/client/go/internal/ioutil"
 )
 
 type ApplicationPackage struct {
@@ -24,7 +24,7 @@ func (ap *ApplicationPackage) HasDeploymentSpec() bool { return ap.hasFile("depl
 
 func (ap *ApplicationPackage) hasFile(pathSegment ...string) bool {
 	if !ap.IsZip() {
-		return util.PathExists(filepath.Join(append([]string{ap.Path}, pathSegment...)...))
+		return ioutil.Exists(filepath.Join(append([]string{ap.Path}, pathSegment...)...))
 	}
 	zipName := filepath.Join(pathSegment...)
 	return ap.hasZipEntry(func(name string) bool { return zipName == name })
@@ -50,7 +50,7 @@ func (ap *ApplicationPackage) IsJava() bool {
 	if ap.IsZip() {
 		return ap.hasZipEntry(func(name string) bool { return filepath.Ext(name) == ".jar" })
 	}
-	return util.PathExists(filepath.Join(ap.Path, "pom.xml"))
+	return ioutil.Exists(filepath.Join(ap.Path, "pom.xml"))
 }
 
 func (ap *ApplicationPackage) Validate() error {
@@ -74,11 +74,11 @@ func (ap *ApplicationPackage) Validate() error {
 func isZip(filename string) bool { return filepath.Ext(filename) == ".zip" }
 
 func zipDir(dir string, destination string) error {
-	if !util.PathExists(dir) {
+	if !ioutil.Exists(dir) {
 		message := "'" + dir + "' should be an application package zip or dir, but does not exist"
 		return errors.New(message)
 	}
-	if !util.IsDirectory(dir) {
+	if !ioutil.IsDir(dir) {
 		message := "'" + dir + "' should be an application package dir, but is a (non-zip) file"
 		return errors.New(message)
 	}
@@ -267,10 +267,10 @@ func findApplicationPackage(zipOrDir string, options PackageOptions) (Applicatio
 	}
 	// Pre-packaged application. We prefer the uncompressed application because this allows us to add
 	// security/clients.pem to the package on-demand
-	hasPOM := util.PathExists(filepath.Join(zipOrDir, "pom.xml"))
+	hasPOM := ioutil.Exists(filepath.Join(zipOrDir, "pom.xml"))
 	if hasPOM && !options.SourceOnly {
 		path := filepath.Join(zipOrDir, "target", "application")
-		if util.PathExists(path) {
+		if ioutil.Exists(path) {
 			testPath := existingPath(filepath.Join(zipOrDir, "target", "application-test"))
 			return ApplicationPackage{Path: path, TestPath: testPath}, nil
 		}
@@ -279,14 +279,14 @@ func findApplicationPackage(zipOrDir string, options PackageOptions) (Applicatio
 		}
 	}
 	// Application with Maven directory structure, but with no POM or no hard requirement on packaging
-	if path := filepath.Join(zipOrDir, "src", "main", "application"); util.PathExists(path) {
+	if path := filepath.Join(zipOrDir, "src", "main", "application"); ioutil.Exists(path) {
 		testPath := existingPath(filepath.Join(zipOrDir, "src", "test", "application"))
 		return ApplicationPackage{Path: path, TestPath: testPath}, nil
 	}
 	// Application without Java components
-	if util.PathExists(filepath.Join(zipOrDir, "services.xml")) {
+	if ioutil.Exists(filepath.Join(zipOrDir, "services.xml")) {
 		testPath := ""
-		if util.PathExists(filepath.Join(zipOrDir, "tests")) {
+		if ioutil.Exists(filepath.Join(zipOrDir, "tests")) {
 			testPath = zipOrDir
 		}
 		return ApplicationPackage{Path: zipOrDir, TestPath: testPath}, nil
@@ -295,7 +295,7 @@ func findApplicationPackage(zipOrDir string, options PackageOptions) (Applicatio
 }
 
 func existingPath(path string) string {
-	if util.PathExists(path) {
+	if ioutil.Exists(path) {
 		return path
 	}
 	return ""
diff --git a/client/go/internal/vespa/crypto.go b/client/go/internal/vespa/crypto.go
index 13d3ac570cc..9b4d776d97d 100644
--- a/client/go/internal/vespa/crypto.go
+++ b/client/go/internal/vespa/crypto.go
@@ -20,7 +20,7 @@ import (
 	"strings"
 	"time"
 
-	"github.com/vespa-engine/vespa/client/go/internal/util"
+	"github.com/vespa-engine/vespa/client/go/internal/ioutil"
 )
 
 const (
@@ -36,18 +36,18 @@ type PemKeyPair struct {
 
 // WriteCertificateFile writes the certificate contained in this key pair to certificateFile.
 func (kp *PemKeyPair) WriteCertificateFile(certificateFile string, overwrite bool) error {
-	if util.PathExists(certificateFile) && !overwrite {
+	if ioutil.Exists(certificateFile) && !overwrite {
 		return fmt.Errorf("cannot overwrite existing file: %s", certificateFile)
 	}
-	return util.AtomicWriteFile(certificateFile, kp.Certificate)
+	return ioutil.AtomicWriteFile(certificateFile, kp.Certificate)
 }
 
 // WritePrivateKeyFile writes the private key contained in this key pair to privateKeyFile.
 func (kp *PemKeyPair) WritePrivateKeyFile(privateKeyFile string, overwrite bool) error {
-	if util.PathExists(privateKeyFile) && !overwrite {
+	if ioutil.Exists(privateKeyFile) && !overwrite {
 		return fmt.Errorf("cannot overwrite existing file: %s", privateKeyFile)
 	}
-	return util.AtomicWriteFile(privateKeyFile, kp.PrivateKey)
+	return ioutil.AtomicWriteFile(privateKeyFile, kp.PrivateKey)
 }
 
 // CreateKeyPair creates a key pair containing a private key and self-signed X509 certificate.
diff --git a/client/go/internal/vespa/deploy.go b/client/go/internal/vespa/deploy.go
index 35fd523f15a..10ddb321e19 100644
--- a/client/go/internal/vespa/deploy.go
+++ b/client/go/internal/vespa/deploy.go
@@ -18,7 +18,7 @@ import (
 	"strings"
 	"time"
 
-	"github.com/vespa-engine/vespa/client/go/internal/util"
+	"github.com/vespa-engine/vespa/client/go/internal/ioutil"
 	"github.com/vespa-engine/vespa/client/go/internal/version"
 )
 
@@ -120,10 +120,10 @@ func ZoneFromString(s string) (ZoneID, error) {
 }
 
 func Fetch(deployment DeploymentOptions, path string) (string, error) {
-	if util.IsDirectory(path) {
+	if ioutil.IsDir(path) {
 		path = filepath.Join(path, "application.zip")
 	}
-	if util.PathExists(path) {
+	if ioutil.Exists(path) {
 		return "", fmt.Errorf("%s already exists", path)
 	}
 	if deployment.Target.IsCloud() {
@@ -540,7 +540,7 @@ func checkResponse(req *http.Request, response *http.Response) error {
 	if response.StatusCode/100 == 4 {
 		return fmt.Errorf("invalid application package (%s)\n%s", response.Status, extractError(response.Body))
 	} else if response.StatusCode != 200 {
-		return fmt.Errorf("error from deploy API at %s (%s):\n%s", req.URL.Host, response.Status, util.ReaderToJSON(response.Body))
+		return fmt.Errorf("error from deploy API at %s (%s):\n%s", req.URL.Host, response.Status, ioutil.ReaderToJSON(response.Body))
 	}
 	return nil
 }
diff --git a/client/go/internal/vespa/deploy_test.go b/client/go/internal/vespa/deploy_test.go
index 516a21e7786..4c2fb912224 100644
--- a/client/go/internal/vespa/deploy_test.go
+++ b/client/go/internal/vespa/deploy_test.go
@@ -14,8 +14,8 @@ import (
 
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
+	"github.com/vespa-engine/vespa/client/go/internal/ioutil"
 	"github.com/vespa-engine/vespa/client/go/internal/mock"
-	"github.com/vespa-engine/vespa/client/go/internal/util"
 	"github.com/vespa-engine/vespa/client/go/internal/version"
 )
 
@@ -235,7 +235,7 @@ func TestFetch(t *testing.T) {
 	dir := t.TempDir()
 	dst, err := Fetch(opts, dir)
 	require.Nil(t, err)
-	assert.True(t, util.PathExists(dst))
+	assert.True(t, ioutil.Exists(dst))
 
 	f, err := os.Open(dst)
 	require.Nil(t, err)
@@ -264,7 +264,7 @@ func TestFetchCloud(t *testing.T) {
 	dir := t.TempDir()
 	dst, err := Fetch(opts, dir)
 	require.Nil(t, err)
-	assert.True(t, util.PathExists(dst))
+	assert.True(t, ioutil.Exists(dst))
 }
 
 type pkgFixture struct {
diff --git a/client/go/internal/vespa/detect_hostname.go b/client/go/internal/vespa/detect_hostname.go
index e6b2d113ec1..062d83d66a4 100644
--- a/client/go/internal/vespa/detect_hostname.go
+++ b/client/go/internal/vespa/detect_hostname.go
@@ -11,7 +11,7 @@ import (
 
 	"github.com/vespa-engine/vespa/client/go/internal/admin/envvars"
 	"github.com/vespa-engine/vespa/client/go/internal/admin/trace"
-	"github.com/vespa-engine/vespa/client/go/internal/util"
+	"github.com/vespa-engine/vespa/client/go/internal/osutil"
 )
 
 // detect if this host is IPv6-only, in which case we want to pass
@@ -109,7 +109,7 @@ func findOurHostnameFrom(name string) (string, error) {
 	if good {
 		return trimmed, nil
 	}
-	backticks := util.BackTicksIgnoreStderr
+	backticks := osutil.BackTicksIgnoreStderr
 	out, err := backticks.Run("vespa-detect-hostname")
 	if err != nil {
 		out, err = backticks.Run("hostname", "-f")
diff --git a/client/go/internal/vespa/document/http.go b/client/go/internal/vespa/document/http.go
index f878938d6fc..3871ab19edd 100644
--- a/client/go/internal/vespa/document/http.go
+++ b/client/go/internal/vespa/document/http.go
@@ -18,7 +18,7 @@ import (
 	"github.com/go-json-experiment/json"
 	"github.com/klauspost/compress/gzip"
 
-	"github.com/vespa-engine/vespa/client/go/internal/util"
+	"github.com/vespa-engine/vespa/client/go/internal/httputil"
 )
 
 type Compression int
@@ -52,7 +52,7 @@ type ClientOptions struct {
 }
 
 type countingHTTPClient struct {
-	client   util.HTTPClient
+	client   httputil.Client
 	inflight atomic.Int64
 }
 
@@ -70,7 +70,7 @@ type pendingDocument struct {
 	err     error
 }
 
-func NewClient(options ClientOptions, httpClients []util.HTTPClient) (*Client, error) {
+func NewClient(options ClientOptions, httpClients []httputil.Client) (*Client, error) {
 	if len(httpClients) < 1 {
 		return nil, fmt.Errorf("need at least one HTTP client")
 	}
diff --git a/client/go/internal/vespa/document/http_test.go b/client/go/internal/vespa/document/http_test.go
index b2c1139f95f..89e9e96064b 100644
--- a/client/go/internal/vespa/document/http_test.go
+++ b/client/go/internal/vespa/document/http_test.go
@@ -10,8 +10,8 @@ import (
 	"testing"
 	"time"
 
+	"github.com/vespa-engine/vespa/client/go/internal/httputil"
 	"github.com/vespa-engine/vespa/client/go/internal/mock"
-	"github.com/vespa-engine/vespa/client/go/internal/util"
 )
 
 type manualClock struct {
@@ -33,7 +33,7 @@ type mockHTTPClient struct {
 
 func TestLeastBusyClient(t *testing.T) {
 	httpClient := mock.HTTPClient{}
-	var httpClients []util.HTTPClient
+	var httpClients []httputil.Client
 	for i := 0; i < 4; i++ {
 		httpClients = append(httpClients, &mockHTTPClient{i, &httpClient})
 	}
@@ -83,7 +83,7 @@ func TestClientSend(t *testing.T) {
 	client, _ := NewClient(ClientOptions{
 		BaseURL: "https://example.com:1337",
 		Timeout: time.Duration(5 * time.Second),
-	}, []util.HTTPClient{&httpClient})
+	}, []httputil.Client{&httpClient})
 	clock := manualClock{t: time.Now(), tick: time.Second}
 	client.now = clock.now
 	var stats Stats
@@ -164,7 +164,7 @@ func TestClientGet(t *testing.T) {
 	client, _ := NewClient(ClientOptions{
 		BaseURL: "https://example.com:1337",
 		Timeout: time.Duration(5 * time.Second),
-	}, []util.HTTPClient{&httpClient})
+	}, []httputil.Client{&httpClient})
 	clock := manualClock{t: time.Now(), tick: time.Second}
 	client.now = clock.now
 	doc := `{
@@ -196,7 +196,7 @@ func TestClientSendCompressed(t *testing.T) {
 	client, _ := NewClient(ClientOptions{
 		BaseURL: "https://example.com:1337",
 		Timeout: time.Duration(5 * time.Second),
-	}, []util.HTTPClient{httpClient})
+	}, []httputil.Client{httpClient})
 
 	bigBody := fmt.Sprintf(`{"fields": {"foo": "%s"}}`, strings.Repeat("s", 512+1))
 	bigDoc := Document{Create: true, Id: mustParseId("id:ns:type::doc1"), Operation: OperationUpdate, Body: []byte(bigBody)}
@@ -313,7 +313,7 @@ func TestClientMethodAndURL(t *testing.T) {
 	httpClient := mock.HTTPClient{}
 	client, _ := NewClient(ClientOptions{
 		BaseURL: "https://example.com/",
-	}, []util.HTTPClient{&httpClient})
+	}, []httputil.Client{&httpClient})
 	for i, tt := range tests {
 		client.options.Timeout = tt.options.Timeout
 		client.options.Route = tt.options.Route
@@ -333,7 +333,7 @@ func benchmarkClientSend(b *testing.B, compression Compression, document Documen
 		Compression: compression,
 		BaseURL:     "https://example.com:1337",
 		Timeout:     time.Duration(5 * time.Second),
-	}, []util.HTTPClient{&httpClient})
+	}, []httputil.Client{&httpClient})
 	b.ResetTimer() // ignore setup
 	for n := 0; n < b.N; n++ {
 		client.Send(document)
diff --git a/client/go/internal/vespa/find_home.go b/client/go/internal/vespa/find_home.go
index 46dcdedd71c..3545ce6a8c7 100644
--- a/client/go/internal/vespa/find_home.go
+++ b/client/go/internal/vespa/find_home.go
@@ -11,7 +11,8 @@ import (
 
 	"github.com/vespa-engine/vespa/client/go/internal/admin/envvars"
 	"github.com/vespa-engine/vespa/client/go/internal/admin/trace"
-	"github.com/vespa-engine/vespa/client/go/internal/util"
+	"github.com/vespa-engine/vespa/client/go/internal/ioutil"
+	"github.com/vespa-engine/vespa/client/go/internal/osutil"
 )
 
 const (
@@ -46,7 +47,7 @@ func FindHome() string {
 		}
 		for _, dir := range strings.Split(os.Getenv(envvars.PATH), ":") {
 			fn := fmt.Sprintf("%s/%s", dir, myProgName)
-			if util.IsRegularFile(fn) {
+			if ioutil.IsFile(fn) {
 				trace.Debug("findPath", myProgName, "=>", dir)
 				return dir
 			}
@@ -56,7 +57,7 @@ func FindHome() string {
 	// detect path from argv[0]
 	for path := findPath(); path != ""; path = dirName(path) {
 		mySelf := fmt.Sprintf("%s/%s", path, scriptUtilsFilename)
-		if util.IsRegularFile(mySelf) {
+		if ioutil.IsFile(mySelf) {
 			trace.Debug("found", mySelf, "VH =>", path)
 			os.Setenv(envvars.VESPA_HOME, path)
 			return path
@@ -82,9 +83,9 @@ func HasFileUnderVespaHome(fn string) (bool, string) {
 func FindAndVerifyVespaHome() string {
 	vespaHome := FindHome()
 	myself := fmt.Sprintf("%s/%s", vespaHome, scriptUtilsFilename)
-	if !util.IsExecutableFile(myself) {
+	if !ioutil.IsExecutable(myself) {
 		trace.Warning("missing or bad file:", myself)
-		util.JustExitMsg("Not a valid VESPA_HOME: " + vespaHome)
+		osutil.ExitMsg("Not a valid VESPA_HOME: " + vespaHome)
 	}
 	return vespaHome
 }
diff --git a/client/go/internal/vespa/load_env.go b/client/go/internal/vespa/load_env.go
index 24e1b1cdefa..a799cbf4f9a 100644
--- a/client/go/internal/vespa/load_env.go
+++ b/client/go/internal/vespa/load_env.go
@@ -14,7 +14,8 @@ import (
 
 	"github.com/vespa-engine/vespa/client/go/internal/admin/envvars"
 	"github.com/vespa-engine/vespa/client/go/internal/admin/trace"
-	"github.com/vespa-engine/vespa/client/go/internal/util"
+	"github.com/vespa-engine/vespa/client/go/internal/ioutil"
+	"github.com/vespa-engine/vespa/client/go/internal/osutil"
 )
 
 const (
@@ -248,7 +249,7 @@ func shellQuote(s string) string {
 	}
 	if i != l {
 		err := fmt.Errorf("expected length %d but was %d", l, i)
-		util.JustExitWith(err)
+		osutil.ExitErr(err)
 	}
 	return string(res)
 }
@@ -276,7 +277,7 @@ func (builder *pathBuilder) applyTo(receiver loadEnvReceiver) {
 }
 
 func (builder *pathBuilder) appendPath(p string) {
-	if !util.IsDirectory(p) {
+	if !ioutil.IsDir(p) {
 		return
 	}
 	for _, elem := range builder.curPath {
diff --git a/client/go/internal/vespa/prestart.go b/client/go/internal/vespa/prestart.go
index 5b29915bcb2..e6932e951ad 100644
--- a/client/go/internal/vespa/prestart.go
+++ b/client/go/internal/vespa/prestart.go
@@ -8,7 +8,7 @@ import (
 	"os"
 
 	"github.com/vespa-engine/vespa/client/go/internal/admin/trace"
-	"github.com/vespa-engine/vespa/client/go/internal/util"
+	"github.com/vespa-engine/vespa/client/go/internal/osutil"
 )
 
 func RunPreStart() error {
@@ -23,7 +23,7 @@ func RunPreStart() error {
 		return err
 	}
 	vespaUid, vespaGid := FindVespaUidAndGid()
-	fixSpec := util.FixSpec{
+	fixSpec := osutil.FixSpec{
 		UserId:   vespaUid,
 		GroupId:  vespaGid,
 		DirMode:  0755,
@@ -57,7 +57,7 @@ func RunPreStart() error {
 	// fix wrong ownerships within directories:
 	var fixer fs.WalkDirFunc = func(path string, d fs.DirEntry, err error) error {
 		if err != nil {
-			util.JustExitWith(err)
+			osutil.ExitErr(err)
 		}
 		if d.IsDir() {
 			fixSpec.FixDir(path)
diff --git a/client/go/internal/vespa/switch_user.go b/client/go/internal/vespa/switch_user.go
index c84da567224..bce59b96f32 100644
--- a/client/go/internal/vespa/switch_user.go
+++ b/client/go/internal/vespa/switch_user.go
@@ -11,7 +11,7 @@ import (
 
 	"github.com/vespa-engine/vespa/client/go/internal/admin/envvars"
 	"github.com/vespa-engine/vespa/client/go/internal/admin/trace"
-	"github.com/vespa-engine/vespa/client/go/internal/util"
+	"github.com/vespa-engine/vespa/client/go/internal/osutil"
 )
 
 const ENV_CHECK = envvars.VESPA_ALREADY_SWITCHED_USER_TO
@@ -55,7 +55,7 @@ func CheckCorrectUser() {
 	if err2 != nil {
 		trace.Warning("note: user.Lookup(", vespaUser, ") failed:", err2)
 	}
-	util.JustExitMsg("running as wrong user. Check your VESPA_USER setting")
+	osutil.ExitMsg("running as wrong user. Check your VESPA_USER setting")
 }
 
 // re-execute a vespa-wrapper action after switching to the vespa user
@@ -87,7 +87,7 @@ func MaybeSwitchUser(action string) error {
 		mySelf := fmt.Sprintf("%s/%s", vespaHome, scriptUtilsFilename)
 		os.Setenv(ENV_CHECK, wantUser.Username)
 		args := []string{SU_PROG, mySelf, action}
-		return util.Execvp(SU_PROG, args)
+		return osutil.Execvp(SU_PROG, args)
 	}
 	return nil
 }
diff --git a/client/go/internal/vespa/target.go b/client/go/internal/vespa/target.go
index 3a76eac0292..543ce2f4a29 100644
--- a/client/go/internal/vespa/target.go
+++ b/client/go/internal/vespa/target.go
@@ -12,7 +12,7 @@ import (
 	"time"
 
 	"github.com/vespa-engine/vespa/client/go/internal/curl"
-	"github.com/vespa-engine/vespa/client/go/internal/util"
+	"github.com/vespa-engine/vespa/client/go/internal/httputil"
 	"github.com/vespa-engine/vespa/client/go/internal/version"
 )
 
@@ -84,7 +84,7 @@ type Service struct {
 
 	deployAPI     bool
 	auth          Authenticator
-	httpClient    util.HTTPClient
+	httpClient    httputil.Client
 	customClient  bool
 	retryInterval time.Duration
 }
@@ -143,7 +143,7 @@ type LogOptions struct {
 func (s *Service) Do(request *http.Request, timeout time.Duration) (*http.Response, error) {
 	if !s.customClient {
 		// Do not override TLS config if a custom client has been configured
-		util.ConfigureTLS(s.httpClient, s.TLSOptions.KeyPair, s.TLSOptions.CACertificate, s.TLSOptions.TrustAll)
+		httputil.ConfigureTLS(s.httpClient, s.TLSOptions.KeyPair, s.TLSOptions.CACertificate, s.TLSOptions.TrustAll)
 	}
 	if s.auth != nil {
 		if err := s.auth.Authenticate(request); err != nil {
@@ -157,7 +157,7 @@ func (s *Service) Do(request *http.Request, timeout time.Duration) (*http.Respon
 }
 
 // SetClient sets a custom HTTP client that this service should use.
-func (s *Service) SetClient(client util.HTTPClient) {
+func (s *Service) SetClient(client httputil.Client) {
 	s.httpClient = client
 	s.customClient = true
 }
diff --git a/client/go/internal/vespa/target_cloud.go b/client/go/internal/vespa/target_cloud.go
index 708810061d2..c063b99edef 100644
--- a/client/go/internal/vespa/target_cloud.go
+++ b/client/go/internal/vespa/target_cloud.go
@@ -12,7 +12,7 @@ import (
 	"strconv"
 	"time"
 
-	"github.com/vespa-engine/vespa/client/go/internal/util"
+	"github.com/vespa-engine/vespa/client/go/internal/httputil"
 	"github.com/vespa-engine/vespa/client/go/internal/version"
 )
 
@@ -35,7 +35,7 @@ type cloudTarget struct {
 	apiOptions        APIOptions
 	deploymentOptions CloudDeploymentOptions
 	logOptions        LogOptions
-	httpClient        util.HTTPClient
+	httpClient        httputil.Client
 	apiAuth           Authenticator
 	deploymentAuth    Authenticator
 	retryInterval     time.Duration
@@ -74,7 +74,7 @@ type logMessage struct {
 }
 
 // CloudTarget creates a Target for the Vespa Cloud or hosted Vespa platform.
-func CloudTarget(httpClient util.HTTPClient, apiAuth Authenticator, deploymentAuth Authenticator,
+func CloudTarget(httpClient httputil.Client, apiAuth Authenticator, deploymentAuth Authenticator,
 	apiOptions APIOptions, deploymentOptions CloudDeploymentOptions,
 	logOptions LogOptions, retryInterval time.Duration) (Target, error) {
 	return &cloudTarget{
diff --git a/client/go/internal/vespa/target_custom.go b/client/go/internal/vespa/target_custom.go
index 0f3817e8c13..9d62f7dc297 100644
--- a/client/go/internal/vespa/target_custom.go
+++ b/client/go/internal/vespa/target_custom.go
@@ -11,14 +11,14 @@ import (
 	"strconv"
 	"time"
 
-	"github.com/vespa-engine/vespa/client/go/internal/util"
+	"github.com/vespa-engine/vespa/client/go/internal/httputil"
 	"github.com/vespa-engine/vespa/client/go/internal/version"
 )
 
 type customTarget struct {
 	targetType    string
 	baseURL       string
-	httpClient    util.HTTPClient
+	httpClient    httputil.Client
 	tlsOptions    TLSOptions
 	retryInterval time.Duration
 }
@@ -36,7 +36,7 @@ type serviceInfo struct {
 }
 
 // LocalTarget creates a target for a Vespa platform running locally.
-func LocalTarget(httpClient util.HTTPClient, tlsOptions TLSOptions, retryInterval time.Duration) Target {
+func LocalTarget(httpClient httputil.Client, tlsOptions TLSOptions, retryInterval time.Duration) Target {
 	return &customTarget{
 		targetType:    TargetLocal,
 		baseURL:       "http://127.0.0.1",
@@ -47,7 +47,7 @@ func LocalTarget(httpClient util.HTTPClient, tlsOptions TLSOptions, retryInterva
 }
 
 // CustomTarget creates a Target for a Vespa platform running at baseURL.
-func CustomTarget(httpClient util.HTTPClient, baseURL string, tlsOptions TLSOptions, retryInterval time.Duration) Target {
+func CustomTarget(httpClient httputil.Client, baseURL string, tlsOptions TLSOptions, retryInterval time.Duration) Target {
 	return &customTarget{
 		targetType:    TargetCustom,
 		baseURL:       baseURL,
diff --git a/client/go/internal/vespa/xml/config.go b/client/go/internal/vespa/xml/config.go
index 05d73474ffc..d1c16b01652 100644
--- a/client/go/internal/vespa/xml/config.go
+++ b/client/go/internal/vespa/xml/config.go
@@ -11,7 +11,6 @@ import (
 	"strconv"
 	"strings"
 
-	"github.com/vespa-engine/vespa/client/go/internal/util"
 	"github.com/vespa-engine/vespa/client/go/internal/vespa"
 )
 
@@ -25,7 +24,7 @@ func init() {
 </deployment>`
 	d, err := ReadDeployment(strings.NewReader(defaultDeploymentRaw))
 	if err != nil {
-		util.JustExitWith(err)
+		panic(err)
 	}
 	DefaultDeployment = d
 }