kubectx/cmd/kubens/list.go
2021-02-02 15:38:27 -08:00

110 lines
2.7 KiB
Go

// Copyright 2021 Google LLC
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package main
import (
"context"
"fmt"
"io"
"os"
"github.com/pkg/errors"
metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
"k8s.io/client-go/kubernetes"
_ "k8s.io/client-go/plugin/pkg/client/auth"
"k8s.io/client-go/tools/clientcmd"
"github.com/ahmetb/kubectx/internal/kubeconfig"
"github.com/ahmetb/kubectx/internal/printer"
)
type ListOp struct{}
func (op ListOp) Run(stdout, stderr io.Writer) error {
kc := new(kubeconfig.Kubeconfig).WithLoader(kubeconfig.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")
}
curNs, err := kc.NamespaceOfContext(ctx)
if err != nil {
return errors.Wrap(err, "cannot read current namespace")
}
ns, err := queryNamespaces(kc)
if err != nil {
return errors.Wrap(err, "could not list namespaces (is the cluster accessible?)")
}
for _, c := range ns {
s := c
if c == curNs {
s = printer.ActiveItemColor.Sprint(c)
}
fmt.Fprintf(stdout, "%s\n", s)
}
return nil
}
func queryNamespaces(kc *kubeconfig.Kubeconfig) ([]string, error) {
if os.Getenv("_MOCK_NAMESPACES") != "" {
return []string{"ns1", "ns2"}, nil
}
clientset, err := newKubernetesClientSet(kc)
if err != nil {
return nil, errors.Wrap(err, "failed to initialize k8s REST client")
}
var out []string
var next string
for {
list, err := clientset.CoreV1().Namespaces().List(
context.Background(),
metav1.ListOptions{
Limit: 500,
Continue: next,
})
if err != nil {
return nil, errors.Wrap(err, "failed to list namespaces from k8s API")
}
next = list.Continue
for _, it := range list.Items {
out = append(out, it.Name)
}
if next == "" {
break
}
}
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)
}