When I'm running a Golang application in a Kubernetes, I want to get the annotations of the pod where it's running.

Is there any library can help me to do that?

CodePudding user response：

You are looking for the library

https://github.com/kubernetes/apimachinery. It has methods like below which can be usefull for your usecase.

func (meta *ObjectMeta) SetAnnotations(annotations map[string]string)
func HasAnnotation(obj ObjectMeta, ann string) bool

Ref:

1. https://pkg.go.dev/k8s.io/[email protected]/pkg/apis/meta/v1#HasAnnotation
2. https://pkg.go.dev/k8s.io/[email protected]/pkg/apis/meta/v1#ObjectMeta.SetAnnotations

CodePudding user response：

Assuming you know the name of the pod of which you want to retrieve the annotations, using example pod nginx-6799fc88d8-mzmcj below:

package main

import (
    "context"
    "fmt"
    metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
    "k8s.io/client-go/kubernetes"
    "k8s.io/client-go/rest"
)

func main() {
    config, _ := rest.InClusterConfig()
    clientset, _ := kubernetes.NewForConfig(config)
    pod, _ := clientset.CoreV1().Pods("default").Get(context.TODO(), "nginx-6799fc88d8-mzmcj", metav1.GetOptions{})
    for annotation_name, annotation_value := range pod.GetAnnotations(){
        fmt.Println(annotation_name, annotation_value)
    }
}

and the result:

$ kubectl logs incluster-app-6dc44ddcf5-dxj8p
cni.projectcalico.org/containerID 7a63f9befd1174d68384adc05735fbcb1482dfe0d312839736531e90fa9fe790
cni.projectcalico.org/podIP 10.0.124.193/32
cni.projectcalico.org/podIPs 10.0.124.193/32