Disable alpha kustomize commands by default.

- enable alpha commands with env KUSTOMIZE_SHOW_ALPHA_COMMANDS=true

kustomize/go.mod

@@ -8,6 +8,7 @@ require (
 	github.com/spf13/pflag v1.0.5
 	sigs.k8s.io/kustomize/api v0.2.0
 	sigs.k8s.io/kustomize/cmd/config v0.0.0
+	sigs.k8s.io/kustomize/kyaml v0.0.0
 	sigs.k8s.io/yaml v1.1.0
 )
 

kustomize/internal/commands/config/config.go

@@ -11,6 +11,7 @@ import (
 	"sigs.k8s.io/kustomize/api/filesys"
 	"sigs.k8s.io/kustomize/api/konfig/builtinpluginconsts"
 	"sigs.k8s.io/kustomize/cmd/config/cmds"
+	"sigs.k8s.io/kustomize/kyaml/commandutil"
 )
 
 // NewCmdConfig returns an instance of 'config' subcommand.
@@ -50,7 +51,9 @@ func newCmdSave(fSys filesys.FileSystem) *cobra.Command {
 			}
 			return o.RunSave(fSys)
 		},
-		Hidden: true, // Don't display this command, but keep it for backwards compatibility.
+		// Alpha version of config is very different than the current version.
+		// If alpha is enabled, don't display this command, but keep it for backwards compatibility.
+		Hidden: commandutil.GetAlphaEnabled(),
 		Deprecated: `The save command is deprecated and will be removed in a future release.
 
 If you require this command file an issue at https://github.com/kubernetes-sigs/kustomize/issues