mirror of
https://github.com/ahmetb/kubectx.git
synced 2025-09-10 04:48:58 +00:00
cd1849d8df
More efficient ns switches with kubens by querying only the namespace (instead of listing all namespaces). Signed-off-by: Ahmet Alp Balkan <ahmetb@google.com>
98 lines
2.5 KiB
Go
98 lines
2.5 KiB
Go
package main
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import (
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"io"
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"os"
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"github.com/pkg/errors"
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errors2 "k8s.io/apimachinery/pkg/api/errors"
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metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
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"github.com/ahmetb/kubectx/internal/cmdutil"
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"github.com/ahmetb/kubectx/internal/kubeconfig"
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"github.com/ahmetb/kubectx/internal/printer"
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)
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type SwitchOp struct {
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Target string // '-' for back and forth, or NAME
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}
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func (s SwitchOp) Run(_, stderr io.Writer) error {
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kc := new(kubeconfig.Kubeconfig).WithLoader(cmdutil.DefaultLoader)
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defer kc.Close()
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if err := kc.Parse(); err != nil {
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return errors.Wrap(err, "kubeconfig error")
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}
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toNS, err := switchNamespace(kc, s.Target)
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if err != nil {
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return err
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}
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err = printer.Success(stderr, "Active namespace is %q", toNS)
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return err
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}
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func switchNamespace(kc *kubeconfig.Kubeconfig, ns string) (string, error) {
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ctx := kc.GetCurrentContext()
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if ctx == "" {
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return "", errors.New("current-context is not set")
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}
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curNS, err := kc.NamespaceOfContext(ctx)
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if ctx == "" {
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return "", errors.New("failed to get current namespace")
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}
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f := NewNSFile(ctx)
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prev, err := f.Load()
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if err != nil {
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return "", errors.Wrap(err, "failed to load previous namespace from file")
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}
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if ns == "-" {
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if prev == "" {
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return "", errors.Errorf("No previous namespace found for current context (%s)", ctx)
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}
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ns = prev
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}
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ok, err := namespaceExists(kc, ns)
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if err != nil {
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return "", errors.Wrap(err, "failed to query if namespace exists (is cluster accessible?)")
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}
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if !ok {
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return "", errors.Errorf("no namespace exists with name %q", ns)
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}
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if err := kc.SetNamespace(ctx, ns); err != nil {
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return "", errors.Wrapf(err, "failed to change to namespace %q", ns)
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}
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if err := kc.Save(); err != nil {
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return "", errors.Wrap(err, "failed to save kubeconfig file")
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}
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if curNS != ns {
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if err := f.Save(curNS); err != nil {
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return "", errors.Wrap(err, "failed to save the previous namespace to file")
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}
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}
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return ns, nil
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}
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func namespaceExists(kc *kubeconfig.Kubeconfig, ns string) (bool, error) {
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// for tests
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if os.Getenv("_MOCK_NAMESPACES") != "" {
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return ns == "ns1" || ns == "ns2", nil
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}
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clientset, err := newKubernetesClientSet(kc)
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if err != nil {
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return false, errors.Wrap(err, "failed to initialize k8s REST client")
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}
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namespace, err := clientset.CoreV1().Namespaces().Get(ns, metav1.GetOptions{})
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if errors2.IsNotFound(err) {
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return false, nil
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}
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return namespace != nil, errors.Wrapf(err, "failed to query "+
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"namespace %q from k8s API", ns)
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}
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