client-go gin的简单整合一（list列表相关操作

Posted 2022-05-06 saynaihe

背景：

完成了client-go连接kubernetes集群-delete相关操作，稍微看过一些B站go圈里最会写js的奇淼 的go 与gin的视频，还有沈叔的一些课程：https://www.jtthink.com/。一般都是习惯先动手的，自己动手操作，有问题就看沈叔的视频与解决思路！

1. client-go gin的简单整合一

注：以下操作环境可能有些许区别（在家写东西用的windows，公司的办公环境个人安装了一台rocky linux）。一下所有路径为相对路径在k8s-demo1项目目录下！

1. go get 安装gin依赖

PS C:\\Users\\zhangpeng\\GolandProjects\\k8s-demo1> go get github.com/gin-gonic/gin
go get: added github.com/gin-contrib/sse v0.1.0
go get: added github.com/gin-gonic/gin v1.7.7
go get: added github.com/go-playground/locales v0.13.0
go get: added github.com/go-playground/universal-translator v0.17.0
go get: added github.com/go-playground/validator/v10 v10.4.1
go get: added github.com/leodido/go-urn v1.2.0
go get: added github.com/mattn/go-isatty v0.0.12
go get: added github.com/ugorji/go/codec v1.1.7

注：linux环境操作省略…如报错缺少其他依赖go get自行按照提示获取安装！

2. 将连接客户端单独封装成一个方法文件

将前面测试环境写的单独的文件拆分。把客户端单独封装成一个单独文件：
src/lib/K8sClient.go

package lib

import (
	"flag"
	"k8s.io/client-go/kubernetes"
	"k8s.io/client-go/tools/clientcmd"
	"k8s.io/client-go/util/homedir"
	"path/filepath"
)

var K8sClient *kubernetes.Clientset

func init() 
	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()
	config, err := clientcmd.BuildConfigFromFlags("", *kubeconfig)
	if err != nil 
		panic(err.Error())
	

	// create the clientset
	c, err := kubernetes.NewForConfig(config)
	if err != nil 
		panic(err.Error())
	
	K8sClient = c

3. 创建service目录创建namespace deployment service对应service文件

以namespace deployment service为例：

src/service/Namespace.go

package service

import (
	"context"
	"github.com/gin-gonic/gin"
	. "k8s-demo1/src/lib"
	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
)

func ListNamespace(g *gin.Context) 
	ns, err := K8sClient.CoreV1().Namespaces().List(context.Background(), metav1.ListOptions)
	if err != nil 
		g.Error(err)
		return
	
	g.JSON(200, ns)

src/service/Deployment.go

package service

import (
	"context"
	"github.com/gin-gonic/gin"
	. "k8s-demo1/src/lib"
	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
)

func ListDeployment(g *gin.Context) 
	ns := g.Query("ns")

	dps, err := K8sClient.AppsV1().Deployments(ns).List(context.Background(), metav1.ListOptions)
	if err != nil 
		g.Error(err)
	
	g.JSON(200, dps)
	return

src/service/Service.go

package service

import (
	"context"
	"github.com/gin-gonic/gin"
	. "k8s-demo1/src/lib"
	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
)

func ListService(g *gin.Context) 
	ns := g.Query("ns")
	svc, err := K8sClient.CoreV1().Services(ns).List(context.Background(), metav1.ListOptions)
	if err != nil 
		g.Error(err)
		return
	
	g.JSON(200, svc)

注：正常的应该是lib.K8sClient引用，import设置为了 . “k8s-demo1/src/lib”！

4.编辑main.go 设置路由

main.go

package main

import (
	"github.com/gin-gonic/gin"
	"k8s-demo1/src/service"
)

func main() 
	r := gin.Default()
	r.GET("/", func(context *gin.Context) 
		context.JSON(200, "hello")
	)
	r.GET("/namespaces", service.ListNamespace)
	r.GET("/deployments", service.ListDeployment)
	r.GET("/service", service.ListService)
	r.Run()

5. 运行main.go,浏览器访问是否正常返回

可以命令行控制台go run main.go 也可以goland直接run main.go

注：此集群非前面的ack集群，为本地内网一个测试集群！故namespace等相关信息输出并不与前面部分对应

1. namespace:

http://127.0.0.1:8080/namespaces

2. deployment

http://127.0.0.1:8080/deployments

http://127.0.0.1:8080/deployments?ns=default 指定命名空间

3. service

http://127.0.0.1:8080/service

http://127.0.0.1:8080/service?ns=default 指定命名空间

基本实现了个人的目的。但是输出的内容太多了，很多东西不需要，想要进一步优化输出自己先要的信息！

2. 更进一步的-定制化输出需要的内容

1.关于namespace

namespace我只想输出空间name! 创建一个struct,并make创建一个切片：
src/service/Namespace.go

package service

import (
	"context"
	"github.com/gin-gonic/gin"
	. "k8s-demo1/src/lib"
	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
)

type Namespace struct 
	Name string


func ListNamespace(g *gin.Context) 
	ns, err := K8sClient.CoreV1().Namespaces().List(context.Background(), metav1.ListOptions)
	if err != nil 
		g.Error(err)
		return
	
	ret := make([]*Namespace, 0)
	for _, item := range ns.Items 
		ret = append(ret, &Namespace
			Name: item.Name,
		)

	
	g.JSON(200, ret)
	return

浏览器访问http://127.0.0.1:8080/namespaces，如下：

2. 关于deployment

参照namespace设置src/service/Deployment.go

package service

import (
	"context"
	"github.com/gin-gonic/gin"
	. "k8s-demo1/src/lib"
	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
)

type Deployment struct 
	Name string


func ListDeployment(g *gin.Context) 
	ns := g.Query("ns")

	dps, err := K8sClient.AppsV1().Deployments(ns).List(context.Background(), metav1.ListOptions)
	if err != nil 
		g.Error(err)
	
	ret := make([]*Deployment, 0)
	for _, item := range dps.Items 
		ret = append(ret, &Deployment
			Name: item.Name,
		)

	
	g.JSON(200, ret)
	return

运行main.go 访问http://127.0.0.1:8080/deployments http://127.0.0.1:8080/deployments?ns=default

3. 关于service

src/service/Service.go如下

package service

import (
	"context"
	"github.com/gin-gonic/gin"
	. "k8s-demo1/src/lib"
	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
)

type Service struct 
	Name string


func ListService(g *gin.Context) 
	ns := g.Query("ns")
	svc, err := K8sClient.CoreV1().Services(ns).List(context.Background(), metav1.ListOptions)
	if err != nil 
		g.Error(err)
		return
	
	ret := make([]*Service, 0)
	for _, item := range svc.Items 
		ret = append(ret, &Service
			Name: item.Name,
		)

	
	g.JSON(200, ret)
	return

运行main.go 访问http://127.0.0.1:8080/service http://127.0.0.1:8080/service?ns=default

反思：

1.切片的使用，指针的使用…
2.定制化输出更多的相关配置？比如deployments中镜像，副本数。namespace中label？创建时间？
3.gin.Context该让我怎么去理解…