mirror of
https://github.com/kubernetes/client-go.git
synced 2025-09-05 09:01:06 +00:00
Create-update-delete-deployment example using dynamic package
Kubernetes-commit: 103c71a2b576cf2557418df3f235744b1d7f1e4e
This commit is contained in:
Vladimir Vivien
committed by
Kubernetes Publisher
Kubernetes Publisher
parent
f1a699f1fd
commit
abf396d787
208
examples/dynamic-create-update-delete-deployment/main.go
Normal file
208
examples/dynamic-create-update-delete-deployment/main.go
Normal file
@@ -0,0 +1,208 @@
|
||||
/*
|
||||
Copyright 2019 The Kubernetes Authors.
|
||||
|
||||
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.
|
||||
*/
|
||||
|
||||
// Note: the example only works with the code within the same release/branch.
|
||||
package main
|
||||
|
||||
import (
|
||||
"bufio"
|
||||
"flag"
|
||||
"fmt"
|
||||
"os"
|
||||
"path/filepath"
|
||||
|
||||
apiv1 "k8s.io/api/core/v1"
|
||||
metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
|
||||
"k8s.io/apimachinery/pkg/apis/meta/v1/unstructured"
|
||||
"k8s.io/apimachinery/pkg/runtime/schema"
|
||||
"k8s.io/client-go/dynamic"
|
||||
"k8s.io/client-go/tools/clientcmd"
|
||||
"k8s.io/client-go/util/homedir"
|
||||
"k8s.io/client-go/util/retry"
|
||||
//
|
||||
// Uncomment to load all auth plugins
|
||||
// _ "k8s.io/client-go/plugin/pkg/client/auth
|
||||
//
|
||||
// Or uncomment to load specific auth plugins
|
||||
// _ "k8s.io/client-go/plugin/pkg/client/auth/azure"
|
||||
// _ "k8s.io/client-go/plugin/pkg/client/auth/gcp"
|
||||
// _ "k8s.io/client-go/plugin/pkg/client/auth/oidc"
|
||||
// _ "k8s.io/client-go/plugin/pkg/client/auth/openstack"
|
||||
)
|
||||
|
||||
func main() {
|
||||
var kubeconfig *string
|
||||
if home := homedir.HomeDir(); 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()
|
||||
|
||||
namespace := "default"
|
||||
|
||||
config, err := clientcmd.BuildConfigFromFlags("", *kubeconfig)
|
||||
if err != nil {
|
||||
panic(err)
|
||||
}
|
||||
client, err := dynamic.NewForConfig(config)
|
||||
if err != nil {
|
||||
panic(err)
|
||||
}
|
||||
|
||||
deploymentRes := schema.GroupVersionResource{Group: "apps", Version: "v1", Resource: "deployments"}
|
||||
|
||||
deployment := &unstructured.Unstructured{
|
||||
Object: map[string]interface{}{
|
||||
"apiVersion": "apps/v1",
|
||||
"kind": "Deployment",
|
||||
"metadata": map[string]interface{}{
|
||||
"name": "demo-deployment",
|
||||
},
|
||||
"spec": map[string]interface{}{
|
||||
"replicas": 2,
|
||||
"selector": map[string]interface{}{
|
||||
"matchLabels": map[string]interface{}{
|
||||
"app": "demo",
|
||||
},
|
||||
},
|
||||
"template": map[string]interface{}{
|
||||
"metadata": map[string]interface{}{
|
||||
"labels": map[string]interface{}{
|
||||
"app": "demo",
|
||||
},
|
||||
},
|
||||
|
||||
"spec": map[string]interface{}{
|
||||
"containers": []map[string]interface{}{
|
||||
{
|
||||
"name": "web",
|
||||
"image": "nginx:1.12",
|
||||
"ports": []map[string]interface{}{
|
||||
{
|
||||
"name": "http",
|
||||
"protocol": "TCP",
|
||||
"containerPort": 80,
|
||||
},
|
||||
},
|
||||
},
|
||||
},
|
||||
},
|
||||
},
|
||||
},
|
||||
},
|
||||
}
|
||||
|
||||
// Create Deployment
|
||||
fmt.Println("Creating deployment...")
|
||||
result, err := client.Resource(deploymentRes).Namespace(namespace).Create(deployment, metav1.CreateOptions{})
|
||||
if err != nil {
|
||||
panic(err)
|
||||
}
|
||||
fmt.Printf("Created deployment %q.\n", result.GetName())
|
||||
|
||||
// Update Deployment
|
||||
prompt()
|
||||
fmt.Println("Updating deployment...")
|
||||
// You have two options to Update() this Deployment:
|
||||
//
|
||||
// 1. Modify the "deployment" variable and call: Update(deployment).
|
||||
// This works like the "kubectl replace" command and it overwrites/loses changes
|
||||
// made by other clients between you Create() and Update() the object.
|
||||
// 2. Modify the "result" returned by Get() and retry Update(result) until
|
||||
// you no longer get a conflict error. This way, you can preserve changes made
|
||||
// by other clients between Create() and Update(). This is implemented below
|
||||
// using the retry utility package included with client-go. (RECOMMENDED)
|
||||
//
|
||||
// More Info:
|
||||
// https://git.k8s.io/community/contributors/devel/sig-architecture/api-conventions.md#concurrency-control-and-consistency
|
||||
|
||||
retryErr := retry.RetryOnConflict(retry.DefaultRetry, func() error {
|
||||
// Retrieve the latest version of Deployment before attempting update
|
||||
// RetryOnConflict uses exponential backoff to avoid exhausting the apiserver
|
||||
result, getErr := client.Resource(deploymentRes).Namespace(namespace).Get("demo-deployment", metav1.GetOptions{})
|
||||
if getErr != nil {
|
||||
panic(fmt.Errorf("Failed to get latest version of Deployment: %v", getErr))
|
||||
}
|
||||
|
||||
// update replicas to 1
|
||||
if err := unstructured.SetNestedField(result.Object, int64(1), "spec", "replicas"); err != nil {
|
||||
panic(fmt.Errorf("Failed to set replica value: %v", err))
|
||||
}
|
||||
|
||||
// extract spec containers
|
||||
containers, found, err := unstructured.NestedSlice(result.Object, "spec", "template", "spec", "containers")
|
||||
if err != nil || !found || containers == nil {
|
||||
panic(fmt.Errorf("Deployment containers not found or error in spec: %v", err))
|
||||
}
|
||||
|
||||
// update container[0] image
|
||||
if err := unstructured.SetNestedField(containers[0].(map[string]interface{}), "nginx:1.13", "image"); err != nil {
|
||||
panic(err)
|
||||
}
|
||||
if err := unstructured.SetNestedField(result.Object, containers, "spec", "template", "spec", "containers"); err != nil {
|
||||
panic(err)
|
||||
}
|
||||
|
||||
_, updateErr := client.Resource(deploymentRes).Namespace(namespace).Update(result, metav1.UpdateOptions{})
|
||||
return updateErr
|
||||
})
|
||||
if retryErr != nil {
|
||||
panic(fmt.Errorf("Update failed: %v", retryErr))
|
||||
}
|
||||
fmt.Println("Updated deployment...")
|
||||
|
||||
// List Deployments
|
||||
prompt()
|
||||
fmt.Printf("Listing deployments in namespace %q:\n", apiv1.NamespaceDefault)
|
||||
list, err := client.Resource(deploymentRes).Namespace(namespace).List(metav1.ListOptions{})
|
||||
if err != nil {
|
||||
panic(err)
|
||||
}
|
||||
for _, d := range list.Items {
|
||||
replicas, found, err := unstructured.NestedInt64(d.Object, "spec", "replicas")
|
||||
if err != nil || !found {
|
||||
fmt.Printf("Replicas not found for deployment %s: error=%s", d.GetName(), err)
|
||||
continue
|
||||
}
|
||||
fmt.Printf(" * %s (%d replicas)\n", d.GetName(), replicas)
|
||||
}
|
||||
|
||||
// Delete Deployment
|
||||
prompt()
|
||||
fmt.Println("Deleting deployment...")
|
||||
deletePolicy := metav1.DeletePropagationForeground
|
||||
deleteOptions := &metav1.DeleteOptions{
|
||||
PropagationPolicy: &deletePolicy,
|
||||
}
|
||||
if err := client.Resource(deploymentRes).Namespace(namespace).Delete("demo-deployment", deleteOptions); err != nil {
|
||||
panic(err)
|
||||
}
|
||||
|
||||
fmt.Println("Deleted deployment.")
|
||||
}
|
||||
|
||||
func prompt() {
|
||||
fmt.Printf("-> Press Return key to continue.")
|
||||
scanner := bufio.NewScanner(os.Stdin)
|
||||
for scanner.Scan() {
|
||||
break
|
||||
}
|
||||
if err := scanner.Err(); err != nil {
|
||||
panic(err)
|
||||
}
|
||||
fmt.Println()
|
||||
}
|
||||
Reference in New Issue
Block a user