more knecht

knecht/cmd/update.go

@@ -9,6 +9,8 @@ import (
 	"github.com/spf13/cobra"
 )
 
+var pruneEnvFlag bool
+
 var updateCmd = &cobra.Command{
 	Use:   "update <stack>",
 	Short: "Update an existing stack, preserving env vars",
@@ -43,7 +45,7 @@ var updateCmd = &cobra.Command{
 			return err
 		}
 
-		env, err := mergeEnvVars(name, remote.Env, exampleKeys)
+		env, err := mergeEnvVars(name, remote.Env, exampleKeys, pruneEnvFlag)
 		if err != nil {
 			return err
 		}
@@ -64,12 +66,26 @@ var updateCmd = &cobra.Command{
 // mergeEnvVars preserves existing Portainer env vars and prompts via TUI for
 // any keys present in .env.example but missing from Portainer.
 // Returns nil if the user cancelled the form.
-func mergeEnvVars(stackName string, existing []portainer.EnvVar, exampleKeys []string) ([]portainer.EnvVar, error) {
+func mergeEnvVars(stackName string, existing []portainer.EnvVar, exampleKeys []string, prune bool) ([]portainer.EnvVar, error) {
 	envMap := make(map[string]string, len(existing))
 	for _, e := range existing {
 		envMap[e.Name] = e.Value
 	}
 
+	// Remove keys not in .env.example when pruning
+	if prune && exampleKeys != nil {
+		allowed := make(map[string]bool, len(exampleKeys))
+		for _, k := range exampleKeys {
+			allowed[k] = true
+		}
+		for k := range envMap {
+			if !allowed[k] {
+				fmt.Printf("Removing unknown env var %q\n", k)
+				delete(envMap, k)
+			}
+		}
+	}
+
 	var missing []string
 	for _, key := range exampleKeys {
 		if _, ok := envMap[key]; !ok {
@@ -98,5 +114,6 @@ func mergeEnvVars(stackName string, existing []portainer.EnvVar, exampleKeys []s
 }
 
 func init() {
+	updateCmd.Flags().BoolVar(&pruneEnvFlag, "prune-env", false, "remove env vars not defined in .env.example")
 	rootCmd.AddCommand(updateCmd)
 }