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@bells17
Last active February 4, 2020 11:22
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fetch pod & node
package main
import (
"bytes"
"flag"
"fmt"
"html/template"
"os"
"path/filepath"
metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
"k8s.io/client-go/kubernetes"
"k8s.io/client-go/rest"
"k8s.io/client-go/tools/clientcmd"
)
func main() {
// creates the in-cluster config
config, err := rest.InClusterConfig()
if err != nil {
// creates the out-of-cluster config
var kubeconfig *string
if home := os.Getenv("HOME"); home != "" {
kubeconfig = flag.String("kubeconfig", filepath.Join(home, ".kube", "config"), "(optional) absolute path to the kubeconfig file")
} else {
kubeconfig = flag.String("kubeconfig", "", "absolute path to the kubeconfig file")
}
flag.Parse()
// use the current context in kubeconfig
config, err = clientcmd.BuildConfigFromFlags("", *kubeconfig)
if err != nil {
panic(err.Error())
}
}
// creates the clientset
clientset, err := kubernetes.NewForConfig(config)
if err != nil {
panic(err.Error())
}
output, err := outputPods(clientset, "docker-desktop", Tmpl)
if err != nil {
panic(err.Error())
}
fmt.Printf(output)
}
var Tmpl = `
{{range .Items}}Node Name: {{.Spec.NodeName}}
Pod Name: {{.ObjectMeta.Name}}
Pod Namespace: {{.ObjectMeta.Namespace}}
{{end}}
`
func outputPods(clientset *kubernetes.Clientset, nodeName string, tmpl string) (string, error) {
pods, err := clientset.CoreV1().Pods("default").List(metav1.ListOptions{
FieldSelector: "spec.nodeName=" + nodeName,
})
if err != nil {
return "", err
}
t, err := template.New("output").Parse(tmpl)
if err != nil {
return "", err
}
b := new(bytes.Buffer)
err = t.Execute(b, pods)
return b.String(), err
}
$ go run main.go
Node Name: docker-desktop
Pod Name: nginx-pod
Pod Namespace: default
Node Name: docker-desktop
Pod Name: nginx-pod2
Pod Namespace: default
@sravankumar777
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@bells17, I'm sorry to trouble you again.

Recently our team had changed the cluster configuration as insecure and while i'm doing InClusterConfig(), it would be make secure communication. So, i am not able retrieve pods.

However, i did try to make the TLSConfig as insecure: true.
I get error as specifying a root certificates file with the insecure flag is not allowed.

I even tried to make the null configuration of certificates in TLSConfig as below.

config.TLSClientConfig.Insecure = true
config.TLSClientConfig.CertFile = nil
config.TLSClientConfig.CertData = nil
config.TLSClientConfig.CAData = nil

Can you please help me out in this step?

@bells17
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Author

bells17 commented Feb 4, 2020

@sravankumar777

Recently our team had changed the cluster configuration as insecure

Sorry, I have never tried this setting.
Could you tell me about the details of this setting?

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