Use kubeconfig pkg for parsing utils

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

cmd/kubectx/current.go

@@ -5,23 +5,22 @@ import (
 	"io"
 
 	"github.com/pkg/errors"
+
+	"github.com/ahmetb/kubectx/cmd/kubectx/kubeconfig"
 )
 
 // CurrentOp prints the current context
 type CurrentOp struct{}
 
 func (_op CurrentOp) Run(stdout, _ io.Writer) error {
-	cfgPath, err := kubeconfigPath()
+	kc := new(kubeconfig.Kubeconfig).WithLoader(defaultLoader)
+	defer kc.Close()
+	rootNode, err := kc.ParseRaw()
 	if err != nil {
-		return errors.Wrap(err, "failed to determine kubeconfig path")
+		return err
 	}
 
-	cfg, err := parseKubeconfig(cfgPath)
+	v := kubeconfig.GetCurrentContext(rootNode)
-	if err != nil {
-		return errors.Wrap(err, "failed to read kubeconfig file")
-	}
-
-	v := cfg.CurrentContext
 	if v == "" {
 		return errors.New("current-context is not set")
 	}

cmd/kubectx/delete.go

@@ -5,6 +5,8 @@ import (
 
 	"github.com/pkg/errors"
 	"gopkg.in/yaml.v3"
+
+	"github.com/ahmetb/kubectx/cmd/kubectx/kubeconfig"
 )
 
 // DeleteOp indicates intention to delete contexts.
@@ -33,13 +35,14 @@ 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) {
-	f, rootNode, err := openKubeconfig()
+	kc := new(kubeconfig.Kubeconfig).WithLoader(defaultLoader)
+	defer kc.Close()
+	rootNode, err := kc.ParseRaw()
 	if err != nil {
 		return "", false, err
 	}
-	defer f.Close()
 
-	cur := getCurrentContext(rootNode)
+	cur := kubeconfig.GetCurrentContext(rootNode)
 
 	// resolve "." to a real name
 	if name == "." {
@@ -54,7 +57,7 @@ func deleteContext(name string) (deleteName string, wasActiveContext bool, err e
 	if err := modifyDocToDeleteContext(rootNode, name); err != nil {
 		return "", false, errors.Wrap(err, "failed to modify yaml doc")
 	}
-	return name, wasActiveContext, errors.Wrap(saveKubeconfigRaw(f, rootNode), "failed to save kubeconfig file")
+	return name, wasActiveContext, errors.Wrap(kc.Save(), "failed to save kubeconfig file")
 }
 
 func modifyDocToDeleteContext(rootNode *yaml.Node, deleteName string) error {

cmd/kubectx/kubeconfig.go

@@ -10,7 +10,11 @@ import (
 	"github.com/ahmetb/kubectx/cmd/kubectx/kubeconfig"
 )
 
-type defaultKubeconfigLoader struct{}
+var (
+	defaultLoader kubeconfig.Loader = new(StandardKubeconfigLoader)
+)
+
+type StandardKubeconfigLoader struct{}
 
 type kubeconfigFile struct { *os.File }
 
@@ -22,7 +26,7 @@ func (kf *kubeconfigFile) Reset() error {
 	return errors.Wrap(err, "failed to seek in file")
 }
 
-func (defaultKubeconfigLoader) Load() (kubeconfig.ReadWriteResetCloser, error) {
+func (*StandardKubeconfigLoader) Load() (kubeconfig.ReadWriteResetCloser, error) {
 	cfgPath, err := kubeconfigPath()
 	if err != nil {
 		return nil, errors.Wrap(err, "cannot determine kubeconfig path")

cmd/kubectx/kubeconfig/helpers.go

@@ -0,0 +1,47 @@
+package kubeconfig
+
+import "gopkg.in/yaml.v3"
+
+func ContextNames(rootNode *yaml.Node) []string {
+	contexts := valueOf(rootNode, "contexts")
+	if contexts == nil {
+		return nil
+	}
+	if contexts.Kind != yaml.SequenceNode {
+		return nil
+	}
+
+	var ctxNames []string
+	for _, ctx := range contexts.Content {
+		nameVal := valueOf(ctx, "name")
+		if nameVal != nil {
+			ctxNames = append(ctxNames, nameVal.Value)
+		}
+	}
+	return ctxNames
+}
+
+// GetCurrentContext returns "current-context" value in given
+// kubeconfig object Node, or returns "" if not found.
+func GetCurrentContext(rootNode *yaml.Node) string {
+	if rootNode.Kind != yaml.MappingNode {
+		return ""
+	}
+	v := valueOf(rootNode, "current-context")
+	if v == nil {
+		return ""
+	}
+	return v.Value
+}
+
+func valueOf(mapNode *yaml.Node, key string) *yaml.Node {
+	if mapNode.Kind != yaml.MappingNode {
+		return nil
+	}
+	for i, ch := range mapNode.Content {
+		if i%2 == 0 && ch.Kind == yaml.ScalarNode && ch.Value == key {
+			return mapNode.Content[i+1]
+		}
+	}
+	return nil
+}

cmd/kubectx/kubeconfig/kubeconfig.go

@@ -25,8 +25,16 @@ type Kubeconfig struct {
 	rootNode *yaml.Node
 }
 
-func (k *Kubeconfig) WithLoader(l Loader) {
+func (k *Kubeconfig) WithLoader(l Loader) *Kubeconfig {
 	k.loader = l
+	return k
+}
+
+func (k *Kubeconfig) Close() error {
+	if k.f == nil {
+		return nil
+	}
+	return k.f.Close()
 }
 
 func (k *Kubeconfig) ParseRaw() (*yaml.Node, error) {

cmd/kubectx/kubeconfig_raw.go

@@ -1,50 +0,0 @@
-package main
-
-import (
-	"io"
-	"os"
-
-	"github.com/pkg/errors"
-	"gopkg.in/yaml.v3"
-)
-
-func parseKubeconfigRaw(r io.Reader) (*yaml.Node, error) {
-	// TODO DELETE
-	var v yaml.Node
-	if err := yaml.NewDecoder(r).Decode(&v); err != nil {
-		return nil, err
-	}
-	return v.Content[0], nil
-}
-
-func saveKubeconfigRaw(w io.Writer, rootNode *yaml.Node) error {
-	if f, ok := w.(*os.File); ok {
-		if err := f.Truncate(0); err != nil {
-			return errors.Wrap(err, "failed to truncate")
-		}
-		if _, err := f.Seek(0, 0); err != nil {
-			return errors.Wrap(err, "failed to seek")
-		}
-	}
-	enc := yaml.NewEncoder(w)
-	enc.SetIndent(2)
-	return enc.Encode(rootNode)
-}
-
-func openKubeconfig() (f *os.File, rootNode *yaml.Node, err error) {
-	cfgPath, err := kubeconfigPath()
-	if err != nil {
-		return nil, nil, errors.Wrap(err, "cannot determine kubeconfig path")
-	}
-	f, err = os.OpenFile(cfgPath, os.O_RDWR, 0)
-	if err != nil {
-		return nil, nil, errors.Wrap(err, "failed to open file")
-	}
-
-	kc, err := parseKubeconfigRaw(f)
-	if err != nil {
-		f.Close()
-		return nil, nil, errors.Wrap(err, "yaml parse error")
-	}
-	return f, kc, nil
-}

cmd/kubectx/list.go

@@ -6,7 +6,8 @@ import (
 
 	"facette.io/natsort"
 	"github.com/fatih/color"
-	"github.com/pkg/errors"
+
+	"github.com/ahmetb/kubectx/cmd/kubectx/kubeconfig"
 )
 
 type context struct {
@@ -22,30 +23,23 @@ type kubeconfigContents struct {
 // ListOp describes listing contexts.
 type ListOp struct{}
 
-func (_ ListOp) Run(stdout, stderr io.Writer) error {
+func (_ ListOp) Run(stdout, _ io.Writer) error {
-	// TODO extract printing and sorting into a function that's testable
+	kc := new(kubeconfig.Kubeconfig).WithLoader(defaultLoader)
-
+	defer kc.Close()
-	cfgPath, err := kubeconfigPath()
+	rootNode, err := kc.ParseRaw()
 	if err != nil {
-		return errors.Wrap(err, "failed to determine kubeconfig path")
+		return err
 	}
 
-	cfg, err := parseKubeconfig(cfgPath)
+	ctxs := kubeconfig.ContextNames(rootNode)
-	if err != nil {
-		return errors.Wrap(err, "failed to read kubeconfig file")
-	}
-
-	ctxs := make([]string, 0, len(cfg.Contexts))
-	for _, c := range cfg.Contexts {
-		ctxs = append(ctxs, c.Name)
-	}
 	natsort.Sort(ctxs)
 
 	// TODO support KUBECTX_CURRENT_FGCOLOR
 	// TODO support KUBECTX_CURRENT_BGCOLOR
+	cur :=  kubeconfig.GetCurrentContext(rootNode)
 	for _, c := range ctxs {
 		s := c
-		if c == cfg.CurrentContext {
+		if c == cur {
 			s = color.New(color.FgGreen, color.Bold).Sprint(c)
 		}
 		fmt.Fprintf(stdout, "%s\n", s)

cmd/kubectx/rename.go

@@ -6,6 +6,8 @@ import (
 
 	"github.com/pkg/errors"
 	"gopkg.in/yaml.v3"
+
+	"github.com/ahmetb/kubectx/cmd/kubectx/kubeconfig"
 )
 
 // RenameOp indicates intention to rename contexts.
@@ -32,13 +34,15 @@ 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 {
-	f, rootNode, err := openKubeconfig()
+	kc := new(kubeconfig.Kubeconfig).WithLoader(defaultLoader)
-	if err != nil {
+	defer kc.Close()
-		return nil
-	}
-	defer f.Close()
 
-	cur := getCurrentContext(rootNode)
+	rootNode, err := kc.ParseRaw()
+	if err != nil {
+		return err
+	}
+
+	cur := kubeconfig.GetCurrentContext(rootNode)
 	if op.Old == "." {
 		op.Old = cur
 	}
@@ -62,7 +66,7 @@ func (op RenameOp) Run(_, stderr io.Writer) error {
 			return errors.Wrap(err, "failed to set current-context to new name")
 		}
 	}
-	if err := saveKubeconfigRaw(f, rootNode); err != nil {
+	if err := kc.Save(); err != nil {
 		return errors.Wrap(err, "failed to save modified kubeconfig")
 	}
 	printSuccess(stderr, "Context %q renamed to %q.", op.Old, op.New)

cmd/kubectx/switch.go

@@ -5,6 +5,8 @@ import (
 
 	"github.com/pkg/errors"
 	"gopkg.in/yaml.v3"
+
+	"github.com/ahmetb/kubectx/cmd/kubectx/kubeconfig"
 )
 
 // SwitchOp indicates intention to switch contexts.
@@ -33,20 +35,23 @@ func switchContext(name string) (string, error) {
 	if err != nil {
 		return "", errors.Wrap(err, "failed to determine state file")
 	}
-	f, kc, err := openKubeconfig()
+
+	kc := new(kubeconfig.Kubeconfig).WithLoader(defaultLoader)
+	defer kc.Close()
+
+	rootNode, err := kc.ParseRaw()
 	if err != nil {
 		return "", err
 	}
-	defer f.Close()
 
-	prev := getCurrentContext(kc)
+	prev := kubeconfig.GetCurrentContext(rootNode)
-	if !checkContextExists(kc, name) {
+	if !checkContextExists(rootNode, name) {
 		return "", errors.Errorf("no context exists with the name: %q", name)
 	}
-	if err := modifyCurrentContext(kc, name); err != nil {
+	if err := modifyCurrentContext(rootNode, name); err != nil {
 		return "", err
 	}
-	if err := saveKubeconfigRaw(f, kc); err != nil {
+	if err := kc.Save(); err != nil {
 		return "", errors.Wrap(err, "failed to save kubeconfig")
 	}
 
@@ -77,22 +82,7 @@ func swapContext() (string, error) {
 
 
 func checkContextExists(rootNode *yaml.Node, name string) bool {
-	contexts := valueOf(rootNode, "contexts")
+	ctxNames := kubeconfig.ContextNames(rootNode)
-	if contexts == nil {
-		return false
-	}
-	if contexts.Kind != yaml.SequenceNode {
-		return false
-	}
-
-	var ctxNames []string
-	for _, ctx := range contexts.Content {
-		nameVal := valueOf(ctx, "name")
-		if nameVal != nil {
-			ctxNames = append(ctxNames, nameVal.Value)
-		}
-	}
-
 	for _, v := range ctxNames {
 		if v == name {
 			return true
@@ -101,6 +91,7 @@ func checkContextExists(rootNode *yaml.Node, name string) bool {
 	return false
 }
 
+// TODO delete
 func valueOf(mapNode *yaml.Node, key string) *yaml.Node {
 	if mapNode.Kind != yaml.MappingNode {
 		return nil
@@ -113,18 +104,7 @@ func valueOf(mapNode *yaml.Node, key string) *yaml.Node {
 	return nil
 }
 
-// getCurrentContext returns "current-context" value in given
+
-// kubeconfig object Node, or returns "" if not found.
-func getCurrentContext(rootNode *yaml.Node) string {
-	if rootNode.Kind != yaml.MappingNode {
-		return ""
-	}
-	v := valueOf(rootNode, "current-context")
-	if v == nil {
-		return ""
-	}
-	return v.Value
-}
 
 func modifyCurrentContext(rootNode *yaml.Node, name string) error {
 	if rootNode.Kind != yaml.MappingNode {

cmd/kubectx/unset.go

@@ -6,22 +6,26 @@ import (
 
 	"github.com/pkg/errors"
 	"gopkg.in/yaml.v3"
+
+	"github.com/ahmetb/kubectx/cmd/kubectx/kubeconfig"
 )
 
 // UnsetOp indicates intention to remove current-context preference.
 type UnsetOp struct{}
 
 func (_ UnsetOp) Run(_, stderr io.Writer) error {
-	f, rootNode, err := openKubeconfig()
+	kc := new(kubeconfig.Kubeconfig).WithLoader(defaultLoader)
+	defer kc.Close()
+
+	rootNode, err := kc.ParseRaw()
 	if err != nil {
 		return err
 	}
-	defer f.Close()
 
 	if err := modifyDocToUnsetContext(rootNode); err != nil {
 		return errors.Wrap(err, "error while modifying current-context")
 	}
-	if err := saveKubeconfigRaw(f, rootNode); err != nil {
+	if err := kc.Save(); err != nil {
 		return errors.Wrap(err, "failed to save kubeconfig file after modification")
 	}