query namespace exists with GET Namespace (#236)

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>
This commit is contained in:
Ahmet Alp Balkan 2020-05-31 15:32:44 -07:00 committed by GitHub
parent 0141ee19d2
commit 170233bffd
No known key found for this signature in database
GPG Key ID: 4AEE18F83AFDEB23
2 changed files with 29 additions and 16 deletions

View File

@ -54,15 +54,7 @@ func queryNamespaces(kc *kubeconfig.Kubeconfig) ([]string, error) {
return []string{"ns1", "ns2"}, nil
}
b, err := kc.Bytes()
if err != nil {
return nil, errors.Wrap(err, "failed to convert in-memory kubeconfig to yaml")
}
cfg, err := clientcmd.RESTConfigFromKubeConfig(b)
if err != nil {
return nil, errors.Wrap(err, "failed to initialize config")
}
clientset, err := kubernetes.NewForConfig(cfg)
clientset, err := newKubernetesClientSet(kc)
if err != nil {
return nil, errors.Wrap(err, "failed to initialize k8s REST client")
}
@ -87,3 +79,15 @@ func queryNamespaces(kc *kubeconfig.Kubeconfig) ([]string, error) {
}
return out, nil
}
func newKubernetesClientSet(kc *kubeconfig.Kubeconfig) (*kubernetes.Clientset, error) {
b, err := kc.Bytes()
if err != nil {
return nil, errors.Wrap(err, "failed to convert in-memory kubeconfig to yaml")
}
cfg, err := clientcmd.RESTConfigFromKubeConfig(b)
if err != nil {
return nil, errors.Wrap(err, "failed to initialize config")
}
return kubernetes.NewForConfig(cfg)
}

View File

@ -2,8 +2,11 @@ package main
import (
"io"
"os"
"github.com/pkg/errors"
errors2 "k8s.io/apimachinery/pkg/api/errors"
metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
"github.com/ahmetb/kubectx/internal/cmdutil"
"github.com/ahmetb/kubectx/internal/kubeconfig"
@ -75,14 +78,20 @@ func switchNamespace(kc *kubeconfig.Kubeconfig, ns string) (string, error) {
}
func namespaceExists(kc *kubeconfig.Kubeconfig, ns string) (bool, error) {
nses, err := queryNamespaces(kc)
// for tests
if os.Getenv("_MOCK_NAMESPACES") != "" {
return ns == "ns1" || ns == "ns2", nil
}
clientset, err := newKubernetesClientSet(kc)
if err != nil {
return false, err
return false, errors.Wrap(err, "failed to initialize k8s REST client")
}
for _, v := range nses {
if v == ns {
return true, nil
}
namespace, err := clientset.CoreV1().Namespaces().Get(ns, metav1.GetOptions{})
if errors2.IsNotFound(err) {
return false, nil
}
return false, nil
return namespace != nil, errors.Wrapf(err, "failed to query "+
"namespace %q from k8s API", ns)
}