Add config unset command

5 files changed, 64 insertions, 6 deletions

diff --git a/client/go/cmd/config.go b/client/go/cmd/config.go
index 4fa40d02433..b3a0c8133c1 100644
--- a/client/go/cmd/config.go
+++ b/client/go/cmd/config.go
@@ -153,6 +153,42 @@ $ vespa config set --local wait 600
 	return cmd
 }
 
+func newConfigUnsetCmd(cli *CLI) *cobra.Command {
+	var localArg bool
+	cmd := &cobra.Command{
+		Use:   "unset option-name",
+		Short: "Unset a configuration option.",
+		Long: `Unset a configuration option.
+
+Unsetting a configuration option will reset it to its default value, which may be empty.
+`,
+		Example: `# Reset target to its default value
+$ vespa config unset target
+
+# Stop overriding application option in local config
+$ vespa config unset --local application
+`,
+		DisableAutoGenTag: true,
+		SilenceUsage:      true,
+		Args:              cobra.ExactArgs(1),
+		RunE: func(cmd *cobra.Command, args []string) error {
+			config := cli.config
+			if localArg {
+				if _, err := cli.applicationPackageFrom(nil, false); err != nil {
+					return fmt.Errorf("failed to write local configuration: %w", err)
+				}
+				config = cli.config.local
+			}
+			if err := config.unset(args[0]); err != nil {
+				return err
+			}
+			return config.write()
+		},
+	}
+	cmd.Flags().BoolVarP(&localArg, "local", "l", false, "Unset option in local configuration, i.e. for the current application")
+	return cmd
+}
+
 func newConfigGetCmd(cli *CLI) *cobra.Command {
 	var localArg bool
 	cmd := &cobra.Command{
@@ -542,6 +578,14 @@ func (c *Config) set(option, value string) error {
 	return fmt.Errorf("invalid option or value: %s = %s", option, value)
 }
 
+func (c *Config) unset(option string) error {
+	if err := c.checkOption(option); err != nil {
+		return err
+	}
+	c.config.Del(option)
+	return nil
+}
+
 func (c *Config) checkOption(option string) error {
 	if _, ok := c.flags[option]; !ok {
 		return fmt.Errorf("invalid option: %s", option)
diff --git a/client/go/cmd/config_test.go b/client/go/cmd/config_test.go
index a3ce7ee959d..3a8766aae13 100644
--- a/client/go/cmd/config_test.go
+++ b/client/go/cmd/config_test.go
@@ -4,7 +4,6 @@ package cmd
 import (
 	"os"
 	"path/filepath"
-	"strings"
 	"testing"
 
 	"github.com/stretchr/testify/assert"
@@ -51,6 +50,8 @@ func TestConfig(t *testing.T) {
 	assertConfigCommandErr(t, configHome, "Error: invalid option or value: color = foo\n", "config", "set", "color", "foo")
 	assertConfigCommand(t, configHome, "", "config", "set", "color", "never")
 	assertConfigCommand(t, configHome, "color = never\n", "config", "get", "color")
+	assertConfigCommand(t, configHome, "", "config", "unset", "color")
+	assertConfigCommand(t, configHome, "color = auto\n", "config", "get", "color")
 
 	// quiet
 	assertConfigCommand(t, configHome, "", "config", "set", "quiet", "true")
@@ -60,11 +61,14 @@ func TestConfig(t *testing.T) {
 	assertConfigCommand(t, configHome, "", "config", "set", "zone", "dev.us-east-1")
 	assertConfigCommand(t, configHome, "zone = dev.us-east-1\n", "config", "get", "zone")
 
-	// Write empty value, which should be ignored. This is for compatibility with older config formats
+	// Write empty value to YAML config, which should be ignored. This is for compatibility with older config formats
 	configFile := filepath.Join(configHome, "config.yaml")
+	assertConfigCommand(t, configHome, "", "config", "unset", "zone")
 	data, err := os.ReadFile(configFile)
 	require.Nil(t, err)
-	config := strings.ReplaceAll(string(data), "dev.us-east-1", `""`)
+	yamlConfig := string(data)
+	assert.NotContains(t, yamlConfig, "zone:")
+	config := yamlConfig + "zone: \"\"\n"
 	require.Nil(t, os.WriteFile(configFile, []byte(config), 0600))
 	assertConfigCommand(t, configHome, "zone = <unset>\n", "config", "get", "zone")
 }
diff --git a/client/go/cmd/root.go b/client/go/cmd/root.go
index f5e4a3d6016..e88398a7fde 100644
--- a/client/go/cmd/root.go
+++ b/client/go/cmd/root.go
@@ -229,6 +229,7 @@ func (c *CLI) configureCommands() {
 	rootCmd.AddCommand(newCloneCmd(c))              // clone
 	configCmd.AddCommand(newConfigGetCmd(c))        // config get
 	configCmd.AddCommand(newConfigSetCmd(c))        // config set
+	configCmd.AddCommand(newConfigUnsetCmd(c))      // config unset
 	rootCmd.AddCommand(configCmd)                   // config
 	rootCmd.AddCommand(newCurlCmd(c))               // curl
 	rootCmd.AddCommand(newDeployCmd(c))             // deploy
diff --git a/client/go/config/config.go b/client/go/config/config.go
index 7e859d9908a..beffff6e257 100644
--- a/client/go/config/config.go
+++ b/client/go/config/config.go
@@ -46,6 +46,13 @@ func (c *Config) Set(key, value string) {
 	c.values[key] = value
 }
 
+// Del removes the value associated with key.
+func (c *Config) Del(key string) {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+	delete(c.values, key)
+}
+
 // Write writes config in YAML format to writer w.
 func (c *Config) Write(w io.Writer) error {
 	c.mu.RLock()
diff --git a/client/go/config/config_test.go b/client/go/config/config_test.go
index 8bc3835efae..1458771a5f5 100644
--- a/client/go/config/config_test.go
+++ b/client/go/config/config_test.go
@@ -15,12 +15,14 @@ func TestConfig(t *testing.T) {
 	config := New()
 	config.Set("key1", "value1")
 	config.Set("key2", "value2")
-	assert.Equal(t, []string{"key1", "key2"}, config.Keys())
+	config.Set("key3", "value3")
+	assert.Equal(t, []string{"key1", "key2", "key3"}, config.Keys())
 
-	v, ok := config.Get("key1")
+	v, ok := config.Get("key3")
 	assert.True(t, ok)
-	assert.Equal(t, "value1", v)
+	assert.Equal(t, "value3", v)
 
+	config.Del("key3")
 	_, ok = config.Get("key3")
 	assert.False(t, ok)