feat(kubens): added force flag to switch namespaces even if it doesn'… (#416)

* feat(kubens): added force flag to switch namespaces even if it doesn't exist

* Merged lines

* fixed README.md and flags.go

* updated flags.go, flags_test.go

Author: idsulik

README.md

@@ -46,6 +46,15 @@ Active namespace is "kube-system".
 $ kubens -
 Context "test" set.
 Active namespace is "default".
+
+# change the active namespace even if it doesn't exist
+$ kubens not-found-namespace --force
+Context "test" set.
+Active namespace is "not-found-namespace".
+---
+$ kubens not-found-namespace -f
+Context "test" set.
+Active namespace is "not-found-namespace".
 ```
 
 If you have [`fzf`](https://github.com/junegunn/fzf) installed, you can also

cmd/kubens/flags.go

@@ -18,6 +18,7 @@ import (
 	"fmt"
 	"io"
 	"os"
+	"slices"
 	"strings"
 
 	"github.com/ahmetb/kubectx/internal/cmdutil"
@@ -33,28 +34,51 @@ func (op UnsupportedOp) Run(_, _ io.Writer) error {
 // parseArgs looks at flags (excl. executable name, i.e. argv[0])
 // and decides which operation should be taken.
 func parseArgs(argv []string) Op {
-	if len(argv) == 0 {
+	n := len(argv)
+
+	if n == 0 {
 		if cmdutil.IsInteractiveMode(os.Stdout) {
 			return InteractiveSwitchOp{SelfCmd: os.Args[0]}
 		}
 		return ListOp{}
 	}
 
-	if len(argv) == 1 {
+	if n == 1 {
 		v := argv[0]
-		if v == "--help" || v == "-h" {
+		switch v {
+		case "--help", "-h":
 			return HelpOp{}
-		}
-		if v == "--version" || v == "-V" {
+		case "--version", "-V":
 			return VersionOp{}
-		}
-		if v == "--current" || v == "-c" {
+		case "--current", "-c":
 			return CurrentOp{}
+		default:
+			return getSwitchOp(v, false)
 		}
-		if strings.HasPrefix(v, "-") && v != "-" {
-			return UnsupportedOp{Err: fmt.Errorf("unsupported option '%s'", v)}
+	} else if n == 2 {
+		// {namespace} -f|--force
+		name := argv[0]
+		force := slices.Contains([]string{"-f", "--force"}, argv[1])
+
+		if !force {
+			if !slices.Contains([]string{"-f", "--force"}, argv[0]) {
+				return UnsupportedOp{Err: fmt.Errorf("unsupported arguments %q", argv)}
+			}
+
+			// -f|--force {namespace}
+			force = true
+			name = argv[1]
 		}
-		return SwitchOp{Target: argv[0]}
+
+		return getSwitchOp(name, force)
 	}
+
 	return UnsupportedOp{Err: fmt.Errorf("too many arguments")}
 }
+
+func getSwitchOp(v string, force bool) Op {
+	if strings.HasPrefix(v, "-") && v != "-" {
+		return UnsupportedOp{Err: fmt.Errorf("unsupported option %q", v)}
+	}
+	return SwitchOp{Target: v, Force: force}
+}

cmd/kubens/flags_test.go

@@ -48,12 +48,30 @@ func Test_parseArgs_new(t *testing.T) {
 		{name: "switch by name",
 			args: []string{"foo"},
 			want: SwitchOp{Target: "foo"}},
+		{name: "switch by name force short flag",
+			args: []string{"foo", "-f"},
+			want: SwitchOp{Target: "foo", Force: true}},
+		{name: "switch by name force long flag",
+			args: []string{"foo", "--force"},
+			want: SwitchOp{Target: "foo", Force: true}},
+		{name: "switch by name force short flag before name",
+			args: []string{"-f", "foo"},
+			want: SwitchOp{Target: "foo", Force: true}},
+		{name: "switch by name force long flag before name",
+			args: []string{"--force", "foo"},
+			want: SwitchOp{Target: "foo", Force: true}},
+		{name: "switch by name unknown arguments",
+			args: []string{"foo", "-x"},
+			want: UnsupportedOp{Err: fmt.Errorf("unsupported arguments %q", []string{"foo", "-x"})}},
+		{name: "switch by name unknown arguments",
+			args: []string{"-x", "foo"},
+			want: UnsupportedOp{Err: fmt.Errorf("unsupported arguments %q", []string{"-x", "foo"})}},
 		{name: "switch by swap",
 			args: []string{"-"},
 			want: SwitchOp{Target: "-"}},
 		{name: "unrecognized flag",
 			args: []string{"-x"},
-			want: UnsupportedOp{Err: fmt.Errorf("unsupported option '-x'")}},
+			want: UnsupportedOp{Err: fmt.Errorf("unsupported option %q", "-x")}},
 		{name: "too many args",
 			args: []string{"a", "b", "c"},
 			want: UnsupportedOp{Err: fmt.Errorf("too many arguments")}},

cmd/kubens/fzf.go

@@ -65,7 +65,7 @@ func (op InteractiveSwitchOp) Run(_, stderr io.Writer) error {
 	if choice == "" {
 		return errors.New("you did not choose any of the options")
 	}
-	name, err := switchNamespace(kc, choice)
+	name, err := switchNamespace(kc, choice, false)
 	if err != nil {
 		return errors.Wrap(err, "failed to switch namespace")
 	}

cmd/kubens/help.go

@@ -35,6 +35,7 @@ func printUsage(out io.Writer) error {
 	help := `USAGE:
   %PROG%                    : list the namespaces in the current context
   %PROG% <NAME>             : change the active namespace of current context
+  %PROG% <NAME> --force/-f  : force change the active namespace of current context (even if it doesn't exist)
   %PROG% -                  : switch to the previous namespace in this context
   %PROG% -c, --current      : show the current namespace
   %PROG% -h,--help          : show this message

cmd/kubens/switch.go

@@ -29,6 +29,7 @@ import (
 
 type SwitchOp struct {
 	Target string // '-' for back and forth, or NAME
+	Force  bool   // force switch even if the namespace doesn't exist
 }
 
 func (s SwitchOp) Run(_, stderr io.Writer) error {
@@ -38,15 +39,15 @@ func (s SwitchOp) Run(_, stderr io.Writer) error {
 		return errors.Wrap(err, "kubeconfig error")
 	}
 
-	toNS, err := switchNamespace(kc, s.Target)
+	toNS, err := switchNamespace(kc, s.Target, s.Force)
 	if err != nil {
 		return err
 	}
 	err = printer.Success(stderr, "Active namespace is \"%s\"", printer.SuccessColor.Sprint(toNS))
 	return err
 }
 
-func switchNamespace(kc *kubeconfig.Kubeconfig, ns string) (string, error) {
+func switchNamespace(kc *kubeconfig.Kubeconfig, ns string, force bool) (string, error) {
 	ctx := kc.GetCurrentContext()
 	if ctx == "" {
 		return "", errors.New("current-context is not set")
@@ -69,12 +70,14 @@ func switchNamespace(kc *kubeconfig.Kubeconfig, ns string) (string, error) {
 		ns = prev
 	}
 
-	ok, err := namespaceExists(kc, ns)
-	if err != nil {
-		return "", errors.Wrap(err, "failed to query if namespace exists (is cluster accessible?)")
-	}
-	if !ok {
-		return "", errors.Errorf("no namespace exists with name \"%s\"", ns)
+	if !force {
+		ok, err := namespaceExists(kc, ns)
+		if err != nil {
+			return "", errors.Wrap(err, "failed to query if namespace exists (is cluster accessible?)")
+		}
+		if !ok {
+			return "", errors.Errorf("no namespace exists with name \"%s\"", ns)
+		}
 	}
 
 	if err := kc.SetNamespace(ctx, ns); err != nil {