Move kubeconfig loader utils to cmdutil pkg

Signed-off-by: Ahmet Alp Balkan <ahmetb@google.com>

cmd/kubectx/current.go

@@ -6,6 +6,7 @@ import (
 
 	"github.com/pkg/errors"
 
+	"github.com/ahmetb/kubectx/internal/cmdutil"
 	"github.com/ahmetb/kubectx/internal/kubeconfig"
 )
 
@@ -13,7 +14,7 @@ import (
 type CurrentOp struct{}
 
 func (_op CurrentOp) Run(stdout, _ io.Writer) error {
-	kc := new(kubeconfig.Kubeconfig).WithLoader(defaultLoader)
+	kc := new(kubeconfig.Kubeconfig).WithLoader(cmdutil.DefaultLoader)
 	defer kc.Close()
 	if err := kc.Parse(); err != nil {
 		return errors.Wrap(err, "kubeconfig error")

cmd/kubectx/delete.go

@@ -5,6 +5,7 @@ import (
 
 	"github.com/pkg/errors"
 
+	"github.com/ahmetb/kubectx/internal/cmdutil"
 	"github.com/ahmetb/kubectx/internal/kubeconfig"
 	"github.com/ahmetb/kubectx/internal/printer"
 )
@@ -35,7 +36,7 @@ func (op DeleteOp) Run(_, stderr io.Writer) error {
 // deleteContext deletes a context entry by NAME or current-context
 // indicated by ".".
 func deleteContext(name string) (deleteName string, wasActiveContext bool, err error) {
-	kc := new(kubeconfig.Kubeconfig).WithLoader(defaultLoader)
+	kc := new(kubeconfig.Kubeconfig).WithLoader(cmdutil.DefaultLoader)
 	defer kc.Close()
 	if err := kc.Parse(); err != nil {
 		return deleteName, false, errors.Wrap(err, "kubeconfig error")

cmd/kubectx/flags.go

@@ -20,7 +20,7 @@ func (op UnsupportedOp) Run(_, _ io.Writer) error {
 // and decides which operation should be taken.
 func parseArgs(argv []string) Op {
 	if len(argv) == 0 {
-		if env.IsInteractiveMode(os.Stdout) {
+		if cmdutil.IsInteractiveMode(os.Stdout) {
 			return InteractiveSwitchOp{SelfCmd: os.Args[0]}
 		}
 		return ListOp{}

cmd/kubectx/fzf.go

@@ -10,6 +10,7 @@ import (
 
 	"github.com/pkg/errors"
 
+	"github.com/ahmetb/kubectx/internal/cmdutil"
 	"github.com/ahmetb/kubectx/internal/env"
 	"github.com/ahmetb/kubectx/internal/kubeconfig"
 	"github.com/ahmetb/kubectx/internal/printer"
@@ -21,9 +22,9 @@ type InteractiveSwitchOp struct {
 
 func (op InteractiveSwitchOp) Run(_, stderr io.Writer) error {
 	// parse kubeconfig just to see if it can be loaded
-	kc := new(kubeconfig.Kubeconfig).WithLoader(defaultLoader)
+	kc := new(kubeconfig.Kubeconfig).WithLoader(cmdutil.DefaultLoader)
 	if err := kc.Parse(); err != nil {
-		if isENOENT(err) {
+		if cmdutil.IsNotFoundErr(err) {
 			printer.Warning(stderr, "kubeconfig file not found")
 			return nil
 		}

cmd/kubectx/list.go

@@ -3,12 +3,12 @@ package main
 import (
 	"fmt"
 	"io"
-	"os"
 
 	"facette.io/natsort"
 	"github.com/fatih/color"
 	"github.com/pkg/errors"
 
+	"github.com/ahmetb/kubectx/internal/cmdutil"
 	"github.com/ahmetb/kubectx/internal/kubeconfig"
 	"github.com/ahmetb/kubectx/internal/printer"
 )
@@ -17,10 +17,10 @@ import (
 type ListOp struct{}
 
 func (_ ListOp) Run(stdout, stderr io.Writer) error {
-	kc := new(kubeconfig.Kubeconfig).WithLoader(defaultLoader)
+	kc := new(kubeconfig.Kubeconfig).WithLoader(cmdutil.DefaultLoader)
 	defer kc.Close()
 	if err := kc.Parse(); err != nil {
-		if isENOENT(err) {
+		if cmdutil.IsNotFoundErr(err) {
 			printer.Warning(stderr, "kubeconfig file not found")
 			return nil
 		}
@@ -50,14 +50,3 @@ func (_ ListOp) Run(stdout, stderr io.Writer) error {
 	}
 	return nil
 }
-
-// isENOENT determines if the underlying error is os.IsNotExist. Right now
-// errors from github.com/pkg/errors doesn't work with os.IsNotExist.
-func isENOENT(err error) bool {
-	for e := err; e != nil; e = errors.Unwrap(e) {
-		if os.IsNotExist(e) {
-			return true
-		}
-	}
-	return false
-}

cmd/kubectx/rename.go

@@ -6,6 +6,7 @@ import (
 
 	"github.com/pkg/errors"
 
+	"github.com/ahmetb/kubectx/internal/cmdutil"
 	"github.com/ahmetb/kubectx/internal/kubeconfig"
 	"github.com/ahmetb/kubectx/internal/printer"
 )
@@ -34,7 +35,7 @@ func parseRenameSyntax(v string) (string, string, bool) {
 // to the "new" value. If the old refers to the current-context,
 // current-context preference is also updated.
 func (op RenameOp) Run(_, stderr io.Writer) error {
-	kc := new(kubeconfig.Kubeconfig).WithLoader(defaultLoader)
+	kc := new(kubeconfig.Kubeconfig).WithLoader(cmdutil.DefaultLoader)
 	defer kc.Close()
 	if err := kc.Parse(); err != nil {
 		return errors.Wrap(err, "kubeconfig error")

cmd/kubectx/state.go

@@ -6,10 +6,12 @@ import (
 	"path/filepath"
 
 	"github.com/pkg/errors"
+
+	"github.com/ahmetb/kubectx/internal/cmdutil"
 )
 
 func kubectxPrevCtxFile() (string, error) {
-	home := homeDir()
+	home := cmdutil.HomeDir()
 	if home == "" {
 		return "", errors.New("HOME or USERPROFILE environment variable not set")
 	}

cmd/kubectx/state_test.go

@@ -5,6 +5,8 @@ import (
 	"os"
 	"path/filepath"
 	"testing"
+
+	"github.com/ahmetb/kubectx/internal/testutil"
 )
 
 func Test_readLastContext_nonExistingFile(t *testing.T) {
@@ -18,7 +20,7 @@ func Test_readLastContext_nonExistingFile(t *testing.T) {
 }
 
 func Test_readLastContext(t *testing.T) {
-	path, cleanup := testfile(t, "foo")
+	path, cleanup := testutil.TempFile(t, "foo")
 	defer cleanup()
 
 	s, err := readLastContext(path)
@@ -86,3 +88,4 @@ func Test_kubectxFilePath_error(t *testing.T) {
 		t.Fatal(err)
 	}
 }
+

cmd/kubectx/switch.go

@@ -5,6 +5,7 @@ import (
 
 	"github.com/pkg/errors"
 
+	"github.com/ahmetb/kubectx/internal/cmdutil"
 	"github.com/ahmetb/kubectx/internal/kubeconfig"
 	"github.com/ahmetb/kubectx/internal/printer"
 )
@@ -36,7 +37,7 @@ func switchContext(name string) (string, error) {
 		return "", errors.Wrap(err, "failed to determine state file")
 	}
 
-	kc := new(kubeconfig.Kubeconfig).WithLoader(defaultLoader)
+	kc := new(kubeconfig.Kubeconfig).WithLoader(cmdutil.DefaultLoader)
 	defer kc.Close()
 	if err := kc.Parse(); err != nil {
 		return "", errors.Wrap(err, "kubeconfig error")

cmd/kubectx/unset.go

@@ -5,6 +5,7 @@ import (
 
 	"github.com/pkg/errors"
 
+	"github.com/ahmetb/kubectx/internal/cmdutil"
 	"github.com/ahmetb/kubectx/internal/kubeconfig"
 	"github.com/ahmetb/kubectx/internal/printer"
 )
@@ -13,7 +14,7 @@ import (
 type UnsetOp struct{}
 
 func (_ UnsetOp) Run(_, stderr io.Writer) error {
-	kc := new(kubeconfig.Kubeconfig).WithLoader(defaultLoader)
+	kc := new(kubeconfig.Kubeconfig).WithLoader(cmdutil.DefaultLoader)
 	defer kc.Close()
 	if err := kc.Parse(); err != nil {
 		return errors.Wrap(err, "kubeconfig error")

cmd/kubens/current.go

@@ -1,9 +1,32 @@
 package main
 
-import "io"
+import (
+	"fmt"
+	"io"
+
+	"github.com/pkg/errors"
+
+	"github.com/ahmetb/kubectx/internal/cmdutil"
+	"github.com/ahmetb/kubectx/internal/kubeconfig"
+)
 
 type CurrentOp struct{}
 
-func (c CurrentOp) Run(stdout, stderr io.Writer) error {
+func (c CurrentOp) Run(stdout, _ io.Writer) error {
-	panic("implement me")
+	kc := new(kubeconfig.Kubeconfig).WithLoader(cmdutil.DefaultLoader)
+	defer kc.Close()
+	if err := kc.Parse(); err != nil {
+		return errors.Wrap(err, "kubeconfig error")
+	}
+
+	ctx := kc.GetCurrentContext()
+	if ctx == "" {
+		return errors.New("current-context is not set")
+	}
+	ns, err := kc.NamespaceOfContext(ctx)
+	if err != nil {
+		return errors.Wrapf(err, "failed to read namespace of %q", ctx)
+	}
+	_, err = fmt.Fprintln(stdout, ns)
+	return errors.Wrap(err, "write error")
 }

internal/cmdutil/interactive.go

@@ -1,4 +1,4 @@
-package env
+package cmdutil
 
 import (
 	"os"

internal/cmdutil/kubeconfigloader.go

@@ -1,4 +1,4 @@
-package main
+package cmdutil
 
 import (
 	"os"
@@ -10,21 +10,13 @@ import (
 )
 
 var (
-	defaultLoader kubeconfig.Loader = new(StandardKubeconfigLoader)
+	DefaultLoader kubeconfig.Loader = new(StandardKubeconfigLoader)
 )
 
 type StandardKubeconfigLoader struct{}
 
 type kubeconfigFile struct{ *os.File }
 
-func (kf *kubeconfigFile) Reset() error {
-	if err := kf.Truncate(0); err != nil {
-		return errors.Wrap(err, "failed to truncate file")
-	}
-	_, err := kf.Seek(0, 0)
-	return errors.Wrap(err, "failed to seek in file")
-}
-
 func (*StandardKubeconfigLoader) Load() (kubeconfig.ReadWriteResetCloser, error) {
 	cfgPath, err := kubeconfigPath()
 	if err != nil {
@@ -40,6 +32,14 @@ func (*StandardKubeconfigLoader) Load() (kubeconfig.ReadWriteResetCloser, error)
 	return &kubeconfigFile{f}, nil
 }
 
+func (kf *kubeconfigFile) Reset() error {
+	if err := kf.Truncate(0); err != nil {
+		return errors.Wrap(err, "failed to truncate file")
+	}
+	_, err := kf.Seek(0, 0)
+	return errors.Wrap(err, "failed to seek in file")
+}
+
 func kubeconfigPath() (string, error) {
 	// KUBECONFIG env var
 	if v := os.Getenv("KUBECONFIG"); v != "" {
@@ -52,14 +52,14 @@ func kubeconfigPath() (string, error) {
 	}
 
 	// default path
-	home := homeDir()
+	home := HomeDir()
 	if home == "" {
 		return "", errors.New("HOME or USERPROFILE environment variable not set")
 	}
 	return filepath.Join(home, ".kube", "config"), nil
 }
 
-func homeDir() string {
+func HomeDir() string {
 	if v := os.Getenv("XDG_CACHE_HOME"); v != "" {
 		return v
 	}
@@ -69,3 +69,14 @@ func homeDir() string {
 	}
 	return home
 }
+
+// IsNotFoundErr determines if the underlying error is os.IsNotExist. Right now
+// errors from github.com/pkg/errors doesn't work with os.IsNotExist.
+func IsNotFoundErr(err error) bool {
+	for e := err; e != nil; e = errors.Unwrap(e) {
+		if os.IsNotExist(e) {
+			return true
+		}
+	}
+	return false
+}

internal/cmdutil/kubeconfigloader_test.go

@@ -1,7 +1,6 @@
-package main
+package cmdutil
 
 import (
-	"io/ioutil"
 	"os"
 	"path/filepath"
 	"strings"
@@ -61,7 +60,7 @@ func Test_homeDir(t *testing.T) {
 				unsets = append(unsets, testutil.WithEnvVar(e.k, e.v))
 			}
 
-			got := homeDir()
+			got := HomeDir()
 			if got != c.want {
 				t.Errorf("expected:%q got:%q", c.want, got)
 			}
@@ -120,30 +119,12 @@ func Test_kubeconfigPath_envOvverideDoesNotSupportPathSeparator(t *testing.T) {
 
 func TestStandardKubeconfigLoader_returnsNotFoundErr(t *testing.T) {
 	defer testutil.WithEnvVar("KUBECONFIG", "foo")()
-	kc := new(kubeconfig.Kubeconfig).WithLoader(defaultLoader)
+	kc := new(kubeconfig.Kubeconfig).WithLoader(DefaultLoader)
 	err := kc.Parse()
 	if err == nil {
 		t.Fatal("expected err")
 	}
-	if !isENOENT(err) {
+	if !IsNotFoundErr(err) {
 		t.Fatalf("expected ENOENT error; got=%v", err)
 	}
 }
-
-func testfile(t *testing.T, contents string) (path string, cleanup func()) {
-	t.Helper()
-
-	f, err := ioutil.TempFile(os.TempDir(), "test-file")
-	if err != nil {
-		t.Fatalf("failed to create test file: %v", err)
-	}
-	path = f.Name()
-	if _, err := f.Write([]byte(contents)); err != nil {
-		t.Fatalf("failed to write to test file: %v", err)
-	}
-
-	return path, func() {
-		f.Close()
-		os.Remove(path)
-	}
-}

internal/kubeconfig/helpers_test.go

@@ -1 +0,0 @@
-package kubeconfig

internal/kubeconfig/namespace.go

@@ -0,0 +1,39 @@
+package kubeconfig
+
+import (
+	"github.com/pkg/errors"
+	"gopkg.in/yaml.v3"
+)
+
+const (
+	defaultNamespace = "default"
+)
+
+func (k *Kubeconfig) contextNode(name string) (*yaml.Node, error) {
+	contexts := valueOf(k.rootNode, "contexts")
+	if contexts == nil {
+		return nil, errors.New("\"contexts\" entry is nil")
+	} else if contexts.Kind != yaml.SequenceNode {
+		return nil, errors.New("\"contexts\" is not a sequence node")
+	}
+
+	for _, contextNode := range contexts.Content {
+		nameNode := valueOf(contextNode, "name")
+		if nameNode.Kind == yaml.ScalarNode && nameNode.Value == name {
+			return contextNode, nil
+		}
+	}
+	return nil, errors.Errorf("context with name %q not found", name)
+}
+
+func (k *Kubeconfig) NamespaceOfContext(contextName string) (string, error) {
+	ctx, err := k.contextNode(contextName)
+	if err != nil {
+		return "", err
+	}
+	ns := valueOf(ctx, "namespace")
+	if ns == nil || ns.Value == "" {
+		return defaultNamespace, nil
+	}
+	return ns.Value, nil
+}

internal/kubeconfig/namespace_test.go

@@ -0,0 +1,46 @@
+package kubeconfig
+
+import (
+	"testing"
+
+	"github.com/ahmetb/kubectx/internal/testutil"
+)
+
+func TestKubeconfig_NamespaceOfContext_ctxNotFound(t *testing.T) {
+	kc := new(Kubeconfig).WithLoader(WithMockKubeconfigLoader(testutil.KC().
+		WithCtxs(testutil.Ctx("c1")).ToYAML(t)))
+	if err := kc.Parse(); err != nil {
+		t.Fatal(err)
+	}
+
+	_, err := kc.NamespaceOfContext("c2")
+	if err == nil {
+		t.Fatal("expected err")
+	}
+}
+
+func TestKubeconfig_NamespaceOfContext(t *testing.T) {
+	kc := new(Kubeconfig).WithLoader(WithMockKubeconfigLoader(testutil.KC().
+		WithCtxs(
+			testutil.Ctx("c1"),
+			testutil.Ctx("c2").Ns("c2n1")).ToYAML(t)))
+	if err := kc.Parse(); err != nil {
+		t.Fatal(err)
+	}
+
+	v1, err := kc.NamespaceOfContext("c1")
+	if err != nil {
+		t.Fatal("expected err")
+	}
+	if expected := `default`; v1 != expected {
+		t.Fatalf("c1: expected=%q got=%q", expected, v1)
+	}
+
+	v2, err := kc.NamespaceOfContext("c2")
+	if err != nil {
+		t.Fatal("expected err")
+	}
+	if expected := `c2n1`; v2 != expected {
+		t.Fatalf("c2: expected=%q got=%q", expected, v2)
+	}
+}

internal/testutil/kubeconfigbuilder.go

@@ -12,7 +12,8 @@ type Context struct {
 	Namespace string `yaml:"namespace,omitempty"`
 }
 
-func Ctx(name string) *Context { return &Context{Name: name} }
+func Ctx(name string) *Context           { return &Context{Name: name} }
+func (c *Context) Ns(ns string) *Context { c.Namespace = ns; return c }
 
 type Kubeconfig map[string]interface{}
 

internal/testutil/tempfile.go

@@ -0,0 +1,26 @@
+package testutil
+
+import (
+	"io/ioutil"
+	"os"
+	"testing"
+)
+
+func TempFile(t *testing.T, contents string) (path string, cleanup func()) {
+	// TODO consider removing, used only in one place.
+	t.Helper()
+
+	f, err := ioutil.TempFile(os.TempDir(), "test-file")
+	if err != nil {
+		t.Fatalf("failed to create test file: %v", err)
+	}
+	path = f.Name()
+	if _, err := f.Write([]byte(contents)); err != nil {
+		t.Fatalf("failed to write to test file: %v", err)
+	}
+
+	return path, func() {
+		f.Close()
+		os.Remove(path)
+	}
+}