Download: https://github.com/kubernetes/client-go
Official Use Document Reference: https://v1-16.docs.kubernetes.io/docs/reference/using-api/client-libraries/
Installation for kubernetes1.15.6 version of kubernetes use of cluster
go get -u -v k8s.io/[email protected]
In exemplary operation of an external cluster k8s
Create a clientSet
package main
import (
"flag"
"fmt"
apiv1 "k8s.io/api/core/v1"
metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
appv1 "k8s.io/api/apps/v1"
"k8s.io/client-go/kubernetes"
"k8s.io/client-go/rest"
"k8s.io/client-go/tools/clientcmd"
)
func main() {
where (
k8sconfig = flag.String ( "k8sconfig", "./admin.conf", "kubernetes auth config") // use kubeconfig cluster configuration file certification authority
config *rest.Config
err error
)
flag.Parse()
config, err = clientcmd.BuildConfigFromFlags("", *k8sconfig)
if err != nil {
fmt.Println(err)
return
}
// Create a new clientset from the specified config
clientset, err := kubernetes.NewForConfig(config)
if err != nil {
fmt.Println(err)
return
} else {
fmt.Println("connect kubernetes cluster success.")
}
Obtain information about the specified namespace in the pod
// Get a list pod to pod namespace level of resources required to specify the name space
pods, err := clientset.CoreV1().Pods("default").List(metav1.ListOptions{})
if err != nil {
panic(err)
}
// print circulation of information pod
for _,pod := range pods.Items {
fmt.Println(pod.ObjectMeta.Name,pod.Status.Phase)
}
Create a namespace
nsClient := clientset.CoreV1().Namespaces()
ns := &apiv1.Namespace{
ObjectMeta:metav1.ObjectMeta{
Name: "testzhangsan",
},
Status:apiv1.NamespaceStatus{
Phase:apiv1.NamespaceActive,
},
}
ns,err = nsClient.Create(ns)
if err != nil{
panic(err)
}
fmt.Println(ns.ObjectMeta.Name,ns.Status.Phase)
Gets the namespace information under svc
svclist,err := clientset.CoreV1().Services("kube-system").List(metav1.ListOptions{})
for _,svc := range svclist.Items {
fmt.Println(svc.Name,svc.Spec.ClusterIP,svc.Spec.Ports)
}
Create a deployment controller
Listing kubernetes resource controller, as shown below, it is necessary to create a controller according to the exemplary client library according to the list of resources
apiVersion: v1
kind: Pod
metadata:
name: test-pod
namespace: default
labels:
app: redis
spec:
containers:
- name: redis-app
Image: repeat
imagePullPolicy: IfNotPresent
ports:
- name: redis
containerPort: 6379
- name: busybox
image: busybox
command:
- "/bin/sh"
- "-c"
- "sleep 3600"
The format is as follows deployment controller structure, according to this structure need to create
// Deployment enables declarative updates for Pods and ReplicaSets.
type Deployment struct {
metav1.TypeMeta `json:",inline"`
// Standard object metadata.
// +optional
metav1.ObjectMeta `json:"metadata,omitempty" protobuf:"bytes,1,opt,name=metadata"`
// Specification of the desired behavior of the Deployment.
// +optional
Spec DeploymentSpec `json:"spec,omitempty" protobuf:"bytes,2,opt,name=spec"`
// Most recently observed status of the Deployment.
// +optional
Status DeploymentStatus `json:"status,omitempty" protobuf:"bytes,3,opt,name=status"`
}
Required metadata spec and two options
Therefore, we need to create two structures, metadate need only a simple name and label definitions can be
ObjectMeta:metav1.ObjectMeta{
Name: "testgolangclient",
},
spec defined for the attribute information and the number of copies of the pod. A format structure as complete deployment controller
type DeploymentSpec struct {
// Number of desired pods. This is a pointer to distinguish between explicit
// zero and not specified. Defaults to 1.
// +optional
Replicas *int32 `json:"replicas,omitempty" protobuf:"varint,1,opt,name=replicas"`
// Label selector for pods. Existing ReplicaSets whose pods are
// selected by this will be the ones affected by this deployment.
// It must match the pod template's labels.
Selector *metav1.LabelSelector `json:"selector" protobuf:"bytes,2,opt,name=selector"`
// Template describes the pods that will be created.
Template v1.PodTemplateSpec `json:"template" protobuf:"bytes,3,opt,name=template"`
// The deployment strategy to use to replace existing pods with new ones.
// +optional
// +patchStrategy=retainKeys
Strategy DeploymentStrategy `json:"strategy,omitempty" patchStrategy:"retainKeys" protobuf:"bytes,4,opt,name=strategy"`
// Minimum number of seconds for which a newly created pod should be ready
// without any of its container crashing, for it to be considered available.
// Defaults to 0 (pod will be considered available as soon as it is ready)
// +optional
MinReadySeconds int32 `json:"minReadySeconds,omitempty" protobuf:"varint,5,opt,name=minReadySeconds"`
// The number of old ReplicaSets to retain to allow rollback.
// This is a pointer to distinguish between explicit zero and not specified.
// Defaults to 10.
// +optional
RevisionHistoryLimit *int32 `json:"revisionHistoryLimit,omitempty" protobuf:"varint,6,opt,name=revisionHistoryLimit"`
// Indicates that the deployment is paused.
// +optional
Paused bool `json:"paused,omitempty" protobuf:"varint,7,opt,name=paused"`
// The maximum time in seconds for a deployment to make progress before it
// is considered to be failed. The deployment controller will continue to
// process failed deployments and a condition with a ProgressDeadlineExceeded
// reason will be surfaced in the deployment status. Note that progress will
// not be estimated during the time a deployment is paused. Defaults to 600s.
ProgressDeadlineSeconds *int32 `json:"progressDeadlineSeconds,omitempty" protobuf:"varint,9,opt,name=progressDeadlineSeconds"`
}
Here is simple to create a deployment controller, it is simply the number of copies selector template can be.
The structure is as follows spec properties in the resource list
type PodTemplateSpec struct {
// Standard object's metadata.
// More info: https://git.k8s.io/community/contributors/devel/sig-architecture/api-conventions.md#metadata
// +optional
metav1.ObjectMeta `json:"metadata,omitempty" protobuf:"bytes,1,opt,name=metadata"`
// Specification of the desired behavior of the pod.
// More info: https://git.k8s.io/community/contributors/devel/sig-architecture/api-conventions.md#spec-and-status
// +optional
Spec PodSpec `json:"spec,omitempty" protobuf:"bytes,2,opt,name=spec"`
}
Here it is necessary to define the number of copies, a selector, podspec, and the number of copies of a digital type int32, the tag selector a map [string] string array
It is defined as follows
repl: = int32 (1) // number of copies
match: = make (map [string] string) // tag selector
match["app"] = "nginx"
var podSpec = apiv1.Container {
Name: "golang-client",
Picture: "repeat"
ImagePullPolicy:"IfNotPresent",
}
containers := []apiv1.Container{podSpec}
var templateSpec = apiv1.PodTemplateSpec {
ObjectMeta:metav1.ObjectMeta{
Name:"testpod",
Labels:match,
},
Spec: apiv1.PodSpec{
Containers:containers,
},
}
Define deployment controller format
selecter := metav1.LabelSelector{
MatchLabels: match,
}
deploy := appv1.Deployment{
ObjectMeta:metav1.ObjectMeta{
Name: "testgolangclient",
},
Spec: appv1.DeploymentSpec{
Replicas: &repl,
Selector:&selecter,
Template:templateSpec,
},
}
Created deplyment controller
podsClient,err := clientset.AppsV1().Deployments("default" /* 名称空间 */).Create(&deploy)
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