From b22ee71258dc877dc6f2fa2aaff28cb36753ca37 Mon Sep 17 00:00:00 2001
From: Morteza <mortezaho.1376@gmail.com>
Date: Sat, 2 May 2020 05:14:14 +0430
Subject: [PATCH] kubens: add force option for ns switch

---
 cmd/kubens/flags.go      | 19 +++++++++++++++----
 cmd/kubens/flags_test.go | 10 ++++++++--
 cmd/kubens/fzf.go        |  2 +-
 cmd/kubens/switch.go     | 21 ++++++++++++---------
 4 files changed, 36 insertions(+), 16 deletions(-)

diff --git a/cmd/kubens/flags.go b/cmd/kubens/flags.go
index 8e0ad3dc..d796a1e0 100644
--- a/cmd/kubens/flags.go
+++ b/cmd/kubens/flags.go
@@ -25,8 +25,10 @@ func parseArgs(argv []string) Op {
 		}
 		return ListOp{}
 	}
-
-	if len(argv) == 1 {
+	var isForceSwitch bool
+	isForceSwitch = false
+	ArgsLen := len(argv)
+	if ArgsLen == 1 || ArgsLen == 2 {
 		v := argv[0]
 		if v == "--help" || v == "-h" {
 			return HelpOp{}
@@ -34,10 +36,19 @@ func parseArgs(argv []string) Op {
 		if v == "--current" || v == "-c" {
 			return CurrentOp{}
 		}
-		if strings.HasPrefix(v, "-") && v != "-" {
+		if v == "--force" || v == "-f" {
+			isForceSwitch = true
+		}
+		if strings.HasPrefix(v, "-") && v != "-" && !isForceSwitch {
 			return UnsupportedOp{Err: fmt.Errorf("unsupported option '%s'", v)}
 		}
-		return SwitchOp{Target: argv[0]}
+		if isForceSwitch {
+			if ArgsLen == 1 {
+				return UnsupportedOp{Err: fmt.Errorf("force option needs namespace name")}
+			}
+			return SwitchOp{Target: argv[1], IsForce: isForceSwitch}
+		}
+		return SwitchOp{Target: argv[0], IsForce: isForceSwitch}
 	}
 	return UnsupportedOp{Err: fmt.Errorf("too many arguments")}
 }
diff --git a/cmd/kubens/flags_test.go b/cmd/kubens/flags_test.go
index 5b75d55c..13c4dc0d 100644
--- a/cmd/kubens/flags_test.go
+++ b/cmd/kubens/flags_test.go
@@ -33,10 +33,16 @@ func Test_parseArgs_new(t *testing.T) {
 			want: CurrentOp{}},
 		{name: "switch by name",
 			args: []string{"foo"},
-			want: SwitchOp{Target: "foo"}},
+			want: SwitchOp{Target: "foo", IsForce: false}},
 		{name: "switch by swap",
 			args: []string{"-"},
-			want: SwitchOp{Target: "-"}},
+			want: SwitchOp{Target: "-", IsForce: false}},
+		{name: "switch by name force",
+			args: []string{"-f", "foo"},
+			want: SwitchOp{Target: "foo", IsForce: true}},
+		{name: "switch by name force long form",
+			args: []string{"--force", "foo"},
+			want: SwitchOp{Target: "foo", IsForce: true}},
 		{name: "unrecognized flag",
 			args: []string{"-x"},
 			want: UnsupportedOp{Err: fmt.Errorf("unsupported option '-x'")}},
diff --git a/cmd/kubens/fzf.go b/cmd/kubens/fzf.go
index 8446c627..7c051181 100644
--- a/cmd/kubens/fzf.go
+++ b/cmd/kubens/fzf.go
@@ -51,7 +51,7 @@ 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")
 	}
diff --git a/cmd/kubens/switch.go b/cmd/kubens/switch.go
index 71bf729d..23dba3b5 100644
--- a/cmd/kubens/switch.go
+++ b/cmd/kubens/switch.go
@@ -11,7 +11,8 @@ import (
 )
 
 type SwitchOp struct {
-	Target string // '-' for back and forth, or NAME
+	Target  string // '-' for back and forth, or NAME
+	IsForce bool
 }
 
 func (s SwitchOp) Run(_, stderr io.Writer) error {
@@ -21,7 +22,7 @@ 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.IsForce)
 	if err != nil {
 		return err
 	}
@@ -29,7 +30,7 @@ func (s SwitchOp) Run(_, stderr io.Writer) error {
 	return err
 }
 
-func switchNamespace(kc *kubeconfig.Kubeconfig, ns string) (string, error) {
+func switchNamespace(kc *kubeconfig.Kubeconfig, ns string, isForce bool) (string, error) {
 	ctx := kc.GetCurrentContext()
 	if ctx == "" {
 		return "", errors.New("current-context is not set")
@@ -52,12 +53,14 @@ 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 %q", ns)
+	if !isForce {
+		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 %q", ns)
+		}
 	}
 
 	if err := kc.SetNamespace(ctx, ns); err != nil {