write more unit tests

18 files changed, 86 insertions, 32 deletions

diff --git a/client/go/jvm/mem_avail.go b/client/go/jvm/mem_avail.go
index 78627a9b7bb..579b5aa8049 100644
--- a/client/go/jvm/mem_avail.go
+++ b/client/go/jvm/mem_avail.go
@@ -38,26 +38,42 @@ func parentDir(dir string) string {
 	return dir[:lastSlash]
 }
 
-func vespa_cg2get(filename string) (output string, err error) {
-	_, err = os.Stat("/sys/fs/cgroup/cgroup.controllers")
+func readLineFrom(filename string) (string, error) {
+	content, err := os.ReadFile(filename)
+	s := string(content)
+	if err != nil {
+		return s, err
+	}
+	s = strings.TrimSuffix(s, "\n")
+	if strings.Contains(s, "\n") {
+		return s, fmt.Errorf("unexpected multiple lines in file %s", filename)
+	}
+	return s, nil
+}
+
+func vespa_cg2get(limitname string) (output string, err error) {
+	return vespa_cg2get_impl("", limitname)
+}
+func vespa_cg2get_impl(rootdir, limitname string) (output string, err error) {
+	_, err = os.Stat(rootdir + "/sys/fs/cgroup/cgroup.controllers")
 	if err != nil {
 		trace.Trace("no cgroups:", err)
 		return
 	}
-	cgroup_content, err := os.ReadFile("/proc/self/cgroup")
+	cgroup_content, err := readLineFrom(rootdir + "/proc/self/cgroup")
 	if err != nil {
 		trace.Trace("no cgroup for self:", err)
 		return
 	}
 	min_value := "max"
-	slice := strings.TrimPrefix(string(cgroup_content), "0::")
-	slice = strings.TrimSuffix(slice, "\n")
-	for strings.HasPrefix(slice, "/") {
-		path := fmt.Sprintf("/sys/fs/cgroup%s/%s", slice, filename)
-		fileContents, err := os.ReadFile(path)
+	path := rootdir + "/sys/fs/cgroup"
+	slice := strings.TrimPrefix(cgroup_content, "0::")
+	dirNames := strings.Split(slice, "/")
+	for _, dirName := range dirNames {
+		path = path + dirName + "/"
+		value, err := readLineFrom(path + limitname)
+		trace.Debug("read from", path+limitname, "=>", value)
 		if err == nil {
-			value := strings.TrimSuffix(string(fileContents), "\n")
-			trace.Debug("read from", path, "=>", value)
 			if value == "max" {
 				// nop
 			} else if min_value == "max" {
@@ -68,9 +84,8 @@ func vespa_cg2get(filename string) (output string, err error) {
 				min_value = value
 			}
 		}
-		slice = parentDir(slice)
 	}
-	trace.Trace("min_value:", min_value)
+	trace.Trace("min_value of", limitname, "for cgroups v2:", min_value)
 	return min_value, nil
 }
 
@@ -87,9 +102,7 @@ func getAvailableMemory() AmountOfMemory {
 	available_cgroup := KiloBytesOfMemory(1 << 31)
 	cggetOutput, err := backticks.Run("cgget", "-nv", "-r", "memory.limit_in_bytes", "/")
 	if err != nil {
-		if strings.Contains(cggetOutput, "Cgroup is not mounted") {
-			cggetOutput, err = vespa_cg2get("memory.max")
-		}
+		cggetOutput, err = vespa_cg2get("memory.max")
 	}
 	cggetOutput = strings.TrimSpace(cggetOutput)
 	if err != nil {
@@ -98,7 +111,7 @@ func getAvailableMemory() AmountOfMemory {
 	if err == nil && cggetOutput != "max" {
 		numBytes, err := strconv.ParseInt(cggetOutput, 10, 64)
 		if err == nil && numBytes > (1<<28) {
-			available_cgroup = AmountOfMemory{numBytes: numBytes}
+			available_cgroup = BytesOfMemory(numBytes)
 		} else {
 			trace.Warning("unexpected 'cgget' output:", cggetOutput)
 		}
diff --git a/client/go/jvm/mem_avail_test.go b/client/go/jvm/mem_avail_test.go
new file mode 100644
index 00000000000..34366759523
--- /dev/null
+++ b/client/go/jvm/mem_avail_test.go
@@ -0,0 +1,42 @@
+// Copyright Yahoo. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
+package jvm
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/vespa-engine/vespa/client/go/trace"
+)
+
+func TestCg2Get(t *testing.T) {
+	trace.AdjustVerbosity(2)
+	const MM = "memory.max"
+	res, err := vespa_cg2get(MM)
+
+	res, err = vespa_cg2get_impl("mock-cg2/a", MM)
+	assert.Nil(t, err)
+	assert.Equal(t, "123", res)
+
+	res, err = vespa_cg2get_impl("mock-cg2/b", MM)
+	assert.Nil(t, err)
+	assert.Equal(t, "67430985728", res)
+
+	res, err = vespa_cg2get_impl("mock-cg2/c", MM)
+	assert.Nil(t, err)
+	assert.Equal(t, "9663676416", res)
+}
+
+func TestParseFree(t *testing.T) {
+	res := parseFree(`
+              total        used        free      shared  buff/cache   available
+Mem:          19986         656        3157         218       16172       18832
+Swap:          2047         320        1727
+`)
+	assert.Equal(t, MegaBytesOfMemory(19986), res)
+}
+
+func TestGetAvail(t *testing.T) {
+	trace.AdjustVerbosity(0)
+	available := getAvailableMemory()
+	assert.True(t, available.ToMB() >= 0)
+}
diff --git a/client/go/jvm/mem_options_test.go b/client/go/jvm/mem_options_test.go
index d7bb05000ca..c15143d4758 100644
--- a/client/go/jvm/mem_options_test.go
+++ b/client/go/jvm/mem_options_test.go
@@ -5,7 +5,6 @@ import (
 	"testing"
 
 	"github.com/stretchr/testify/assert"
-	"github.com/vespa-engine/vespa/client/go/trace"
 )
 
 func TestAdjustment(t *testing.T) {
@@ -18,18 +17,3 @@ func TestAdjustment(t *testing.T) {
 	adj := adjustAvailableMemory(MegaBytesOfMemory(31024)).ToMB()
 	assert.Equal(t, 30000, int(adj))
 }
-
-func TestParseFree(t *testing.T) {
-	res := parseFree(`
-              total        used        free      shared  buff/cache   available
-Mem:          19986         656        3157         218       16172       18832
-Swap:          2047         320        1727
-`)
-	assert.Equal(t, MegaBytesOfMemory(19986), res)
-}
-
-func TestGetAvail(t *testing.T) {
-	trace.AdjustVerbosity(0)
-	available := getAvailableMemory()
-	assert.True(t, available.ToMB() >= 0)
-}
diff --git a/client/go/jvm/mock-cg2/a/proc/self/cgroup b/client/go/jvm/mock-cg2/a/proc/self/cgroup
new file mode 100644
index 00000000000..2cc2de315da
--- /dev/null
+++ b/client/go/jvm/mock-cg2/a/proc/self/cgroup
@@ -0,0 +1 @@
+0::/system.slice/sshd.service
diff --git a/client/go/jvm/mock-cg2/a/sys/fs/cgroup/cgroup.controllers b/client/go/jvm/mock-cg2/a/sys/fs/cgroup/cgroup.controllers
new file mode 100644
index 00000000000..acb4d263e65
--- /dev/null
+++ b/client/go/jvm/mock-cg2/a/sys/fs/cgroup/cgroup.controllers
@@ -0,0 +1 @@
+cpuset cpu io memory hugetlb pids rdma
diff --git a/client/go/jvm/mock-cg2/a/sys/fs/cgroup/memory.max b/client/go/jvm/mock-cg2/a/sys/fs/cgroup/memory.max
new file mode 100644
index 00000000000..355295a05af
--- /dev/null
+++ b/client/go/jvm/mock-cg2/a/sys/fs/cgroup/memory.max
@@ -0,0 +1 @@
+max
diff --git a/client/go/jvm/mock-cg2/a/sys/fs/cgroup/system.slice/memory.max b/client/go/jvm/mock-cg2/a/sys/fs/cgroup/system.slice/memory.max
new file mode 100644
index 00000000000..190a18037c6
--- /dev/null
+++ b/client/go/jvm/mock-cg2/a/sys/fs/cgroup/system.slice/memory.max
@@ -0,0 +1 @@
+123
diff --git a/client/go/jvm/mock-cg2/a/sys/fs/cgroup/system.slice/sshd.service/memory.max b/client/go/jvm/mock-cg2/a/sys/fs/cgroup/system.slice/sshd.service/memory.max
new file mode 100644
index 00000000000..355295a05af
--- /dev/null
+++ b/client/go/jvm/mock-cg2/a/sys/fs/cgroup/system.slice/sshd.service/memory.max
@@ -0,0 +1 @@
+max
diff --git a/client/go/jvm/mock-cg2/b/proc/self/cgroup b/client/go/jvm/mock-cg2/b/proc/self/cgroup
new file mode 100644
index 00000000000..8dc7ddcf52f
--- /dev/null
+++ b/client/go/jvm/mock-cg2/b/proc/self/cgroup
@@ -0,0 +1 @@
+0::/init.scope
diff --git a/client/go/jvm/mock-cg2/b/sys/fs/cgroup/cgroup.controllers b/client/go/jvm/mock-cg2/b/sys/fs/cgroup/cgroup.controllers
new file mode 100644
index 00000000000..acb4d263e65
--- /dev/null
+++ b/client/go/jvm/mock-cg2/b/sys/fs/cgroup/cgroup.controllers
@@ -0,0 +1 @@
+cpuset cpu io memory hugetlb pids rdma
diff --git a/client/go/jvm/mock-cg2/b/sys/fs/cgroup/init.scope/memory.max b/client/go/jvm/mock-cg2/b/sys/fs/cgroup/init.scope/memory.max
new file mode 100644
index 00000000000..355295a05af
--- /dev/null
+++ b/client/go/jvm/mock-cg2/b/sys/fs/cgroup/init.scope/memory.max
@@ -0,0 +1 @@
+max
diff --git a/client/go/jvm/mock-cg2/b/sys/fs/cgroup/init.scope/sshd.service/memory.max b/client/go/jvm/mock-cg2/b/sys/fs/cgroup/init.scope/sshd.service/memory.max
new file mode 100644
index 00000000000..355295a05af
--- /dev/null
+++ b/client/go/jvm/mock-cg2/b/sys/fs/cgroup/init.scope/sshd.service/memory.max
@@ -0,0 +1 @@
+max
diff --git a/client/go/jvm/mock-cg2/b/sys/fs/cgroup/memory.max b/client/go/jvm/mock-cg2/b/sys/fs/cgroup/memory.max
new file mode 100644
index 00000000000..ca65b2abde1
--- /dev/null
+++ b/client/go/jvm/mock-cg2/b/sys/fs/cgroup/memory.max
@@ -0,0 +1 @@
+67430985728
diff --git a/client/go/jvm/mock-cg2/c/proc/self/cgroup b/client/go/jvm/mock-cg2/c/proc/self/cgroup
new file mode 100644
index 00000000000..c76235307d0
--- /dev/null
+++ b/client/go/jvm/mock-cg2/c/proc/self/cgroup
@@ -0,0 +1 @@
+0::/system.slice/vespa.service
diff --git a/client/go/jvm/mock-cg2/c/sys/fs/cgroup/cgroup.controllers b/client/go/jvm/mock-cg2/c/sys/fs/cgroup/cgroup.controllers
new file mode 100644
index 00000000000..acb4d263e65
--- /dev/null
+++ b/client/go/jvm/mock-cg2/c/sys/fs/cgroup/cgroup.controllers
@@ -0,0 +1 @@
+cpuset cpu io memory hugetlb pids rdma
diff --git a/client/go/jvm/mock-cg2/c/sys/fs/cgroup/memory.max b/client/go/jvm/mock-cg2/c/sys/fs/cgroup/memory.max
new file mode 100644
index 00000000000..ca65b2abde1
--- /dev/null
+++ b/client/go/jvm/mock-cg2/c/sys/fs/cgroup/memory.max
@@ -0,0 +1 @@
+67430985728
diff --git a/client/go/jvm/mock-cg2/c/sys/fs/cgroup/system.slice/memory.max b/client/go/jvm/mock-cg2/c/sys/fs/cgroup/system.slice/memory.max
new file mode 100644
index 00000000000..355295a05af
--- /dev/null
+++ b/client/go/jvm/mock-cg2/c/sys/fs/cgroup/system.slice/memory.max
@@ -0,0 +1 @@
+max
diff --git a/client/go/jvm/mock-cg2/c/sys/fs/cgroup/system.slice/vespa.service/memory.max b/client/go/jvm/mock-cg2/c/sys/fs/cgroup/system.slice/vespa.service/memory.max
new file mode 100644
index 00000000000..8061635036a
--- /dev/null
+++ b/client/go/jvm/mock-cg2/c/sys/fs/cgroup/system.slice/vespa.service/memory.max
@@ -0,0 +1 @@
+9663676416