DevOps系列文章-Kubernetes实现CI与CD配置

Kubernetes实现CI与CD配置

一、基本介绍

基于 Kubernetes 实现 CI/CD 配置，其实和往常那些 CI/CD 配置并没有太大区别。都是通过 提交代码，拉取代码，构建代码，发布代码来实现的。 只不过要是通过 K8s 来实现的话，则是需要将构建好的代码打包成镜像，通过镜像的方式来运行。

CI/CD 流程图：

开发将代码提交代码仓库后，我们便可以通过在 Jenkins 上配置脚本或是 Pipline 的方式来实现代码发布，其中发布有两种方式，一种是通过手动发布，另外一种可以通过 WebHook 插件来实现提交代码便自动发布（生产环境不建议自动发布）

脚本内容一般分为：克隆代码、编译代码、将编译好的代码打包成镜像、运行镜像几个步骤。

二、基于 Kubernetes 实现 CI/CD 配置

1.配置 GitLab

1）安装 Docker-Compose

[root@k8s-master01 ~]# wget "https://github.com/docker/compose/releases/download/v2.3.2/docker-compose-$(uname -s)-$(uname -m)" -O /usr/local/bin/docker-compose	
[root@k8s-master01 ~]# chmod +x /usr/local/bin/docker-compose
[root@k8s-master01 ~]# docker-compose --version

2）安装 GitLab

[root@k8s-master01 ~]# vim docker-compose.yml
version: '3'
services:
  web:
    image: 'gitlab/gitlab-ce:14.8.5-ce.0'
    restart: always
    hostname: 192.168.59.130
    environment:
      GITLAB_OMNIBUS_CONFIG: |
        external_url 'http://192.168.59.130'
    ports:
      - '1080:80'
      - '1443:443'
      - '1022:22'
    volumes:
      - '/app/gitlab/config:/etc/gitlab'
      - '/app/gitlab/logs:/var/log/gitlab'
      - '/app/gitlab/data:/var/opt/gitlab'
[root@k8s-master01 ~]# docker-compose up -d

2.配置 Jenkins

1）安装 NFS 存储，并配置共享目录

[root@k8s-master01 ~]# yum -y install nfs-utils rpcbind
[root@k8s-master01 ~]# echo "/app/jenkins *(rw,sync,no_root_squash)" > /etc/exports
[root@k8s-master01 ~]# mkdir /app/jenkins
[root@k8s-master01 ~]# systemctl start rpcbind nfs

2）创建 PV 和 PVC

[root@k8s-master01 ~]# vim jenkins-pv.yaml
apiVersion: v1
kind: PersistentVolume
metadata:
  name: jenkins-pv
spec:
  capacity:
    storage: 10Gi
  accessModes:
    - ReadWriteMany
  nfs:
    server: 192.168.59.130
    path: /app/jenkins
---
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: jenkins-pvc
spec:
  resources:
    requests:
      storage: 10Gi
  accessModes:
    - ReadWriteMany   
[root@k8s-master01 ~]# kubectl create -f jenkins-pv.yaml

3）创建 RBAC 授权

[root@k8s-master01 ~]# vim jenkins-sa.yaml
apiVersion: v1
kind: ServiceAccount
metadata:
  name: jenkins-sa
---
apiVersion: rbac.authorization.k8s.io/v1beta1
kind: ClusterRole
metadata:
  name: jenkins-cr
rules:
  - apiGroups: ["extensions","apps"]
    resources: ["deployments"]
    verbs: ["create","delete","get","list","watch","patch","update"]
  - apiGroups: [""]
    resources: ["services"]
    verbs: ["create","delete","get","list","watch","patch","update"]
  - apiGroups: [""]
    resources: ["pods"]
    verbs: ["create","delete","get","list","patch","update"]
  - apiGroups: [""]
    resources: ["pods/exec"]
    verbs: ["create","delete","get","list","patch","update"]
  - apiGroups: [""]
    resources: ["pods/log"]
    verbs: ["get","list","update"]
  - apiGroups: [""]
    resources: ["secrets"]
    verbs: ["get"]
---
apiVersion: rbac.authorization.k8s.io/v1beta1
kind: ClusterRoleBinding
metadata:
  name: jenkins-crb
roleRef:
  kind: ClusterRole
  name: jenkins-cr
  apiGroup: rbac.authorization.k8s.io
subjects:
- kind: ServiceAccount
  name: jenkins-sa
  namespace: default
[root@k8s-master01 ~]# kubectl create -f jenkins-sa.yaml

4）创建 StatefulSet

[root@k8s-master01 ~]# vim jenkins-statefulset.yaml
apiVersion: apps/v1
kind: StatefulSet
metadata:
  name: jenkins
spec:
  serviceName: jenkins
  replicas: 1
  selector:
    matchLabels:
      app: jenkins
  template:
    metadata:
      name: "jenkins"
      labels:
        app: jenkins
    spec:
      serviceAccountName: jenkins-sa
      containers:
      - name: jenkins
        image: jenkins/jenkins:lts
        imagePullPolicy: IfNotPresent
        ports:
        - containerPort: 8080
        - containerPort: 50000
        volumeMounts:
        - name: jenkins
          mountPath: /var/jenkins_home
      volumes:
      - name: jenkins
        persistentVolumeClaim:
          claimName: jenkins-pvc          
[root@k8s-master01 ~]# chown -R 1000 /app/jenkins
[root@k8s-master01 ~]# kubectl create -f jenkins-statefulset.yaml

5）创建 Service

[root@k8s-master01 ~]# vim jenkins-svc.yaml
apiVersion: v1
kind: Service
metadata:
  name: jenkins
spec:
  type: NodePort
  ports:
  - name: http
    port: 8080
    targetPort: 8080
    nodePort: 30080
  - name: agent
    port: 50000
    targetPort: 50000
    nodePort: 30090
  selector:
    app: jenkins
[root@k8s-master01 ~]# kubectl create -f jenkins-svc.yaml

6）配置 Jenkins

[root@k8s-master01 ~]# cat /app/jenkins/secrets/initialAdminPassword 
a303d66e915e4ee5b26648a64fdff4be

http://192.168.59.131:30080/

我们这里安装推荐的插件即可，后面有需求可以再进行安装

3.实现 CI/CD 配置

1）在 Jenkins 宿主机上创建 SSH 密钥

[root@k8s-master01 ~]# ssh-keygen -t rsa							
[root@k8s-master01 ~]# cat ~/.ssh/id_rsa.pub							

将生成的公钥 私钥 移动到 nfs的jenkins的挂载目录下

或者 直接进入jenkins容器内生成ssh密钥

最终都是保存在/app/jenkins/.ssh文件夹 下面

2）将公钥上传到 Gitee上

3）将仓库克隆到本地

[root@k8s-master01 ~]#   git clone git@gitee.com:JavaBigDataStudy/go-devops.git

4）编写 Go 代码

[root@k8s-master01 ~]# cd go-devops
[root@k8s-master01 test]# vim main.go
package main
import (
	"fmt"
	"net/http"
)
func HelloHandler(w http.ResponseWriter, r *http.Request) {
	fmt.Fprintf(w, "Hello World")
}
func main() {
	http.HandleFunc("/", HelloHandler)
	http.ListenAndServe(":8080", nil)
}

5）编写 Dockerfile

[root@k8s-master01 go-devops]# vim Dockerfile
FROM golang:1.16 as builder
ENV GO111MODULE=on \
    GOPROXY=https://goproxy.cn,direct
WORKDIR /app
COPY . .
RUN CGO_ENABLED=0 GOOS=linux GOARCH=amd64 go build -ldflags="-w -s" -o main main.go
FROM busybox:1.28.4
WORKDIR /app
COPY --from=builder /app/ .
EXPOSE 8080
CMD ["./main"]
[root@k8s-master01 go-devops]# docker build -t test-web-server:devops-$(date +%Y-%m-%d-%H-%M-%S) .

6）提交代码

[root@k8s-master01 go-devops]# git add .														# 提交到暂存区
[root@k8s-master01 go-devops]# git config --global user.email "dukng-jker@163.com"		# 配置用户邮箱
[root@k8s-master01 go-devops]# git commit -m "This is test CI/CD"							# 提交到本地仓库
[root@k8s-master01 go-devops]# git push														# 推送到远程仓库

7）创建 Deployment 和 Service

[root@k8s-master01 ~]# vim test-web-server.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
  name: test-web-server
spec:
  replicas: 1
  selector:
    matchLabels:
      app: test-web-server
  template:
    metadata:
      labels:
        app: test-web-server
    spec:
      containers:
      - name: test-web-server
        image: test-web-server:devops-2023-05-20-15-18-13
        imagePullPolicy: IfNotPresent
        ports:
        - containerPort: 8080
---
apiVersion: v1
kind: Service
metadata:
  name: test-web-server
spec:
  type: NodePort
  ports:
  - name: test-web-server
    port: 8080
    targetPort: 8080
    nodePort: 30188
  selector:
    app: test-web-server
[root@k8s-master01 ~]# kubectl create -f test-web-server.yaml

8）编写 Jenkins 发版脚本

[root@k8s-master01 ~]# vim jenkins-test.sh
#!/bin/bash
# 固定时间格式
Second=$(date +%Y-%m-%d-%H-%M-%S)
# 备份旧的镜像
Image=$(kubectl -s https://192.168.59.131:6443 describe pod | grep Image: | awk '{print $2}' | grep test)
echo $Image > /opt/test-image-$Second
# 克隆代码
cd /home/shell
if [ -d go-devops ];
then
  mv go-devops  /opt/test-devops-$Second
  git clone git@gitee.com:JavaBigDataStudy/go-devops.git
else
  git clone git@gitee.com:JavaBigDataStudy/go-devops.git
fi
# 发布新的镜像
cd /home/shell/go-devops && docker build -t test-web-server:devops-$Second .
# 上传到镜像仓库
if [ $? -eq 0 ];
then
  docker tag test-web-server:devops-$Second 192.168.59.130:5000/test-web-server:devops-$Second
  docker push 192.168.59.130:5000/test-web-server:devops-$Second
else
  exit 1			# 退出 (防止运行下面命令)
fi
# 替换镜像
sed -i 's/image:.*/image: 192.168.59.130:5000\/test-web-server:devops-'$Second'/g' /home/shell/test-web-server.yaml
# 重启应用
kubectl delete -f /home/shell/test-web-server.yaml
kubectl create -f /home/shell/test-web-server.yaml

[root@k8s-master01 ~]# chmod +x  jenkins-test.sh

上面这个脚本有两步需要注意：

上传到镜像仓库： 如果你们没有自己的镜像仓库，可以选择调整脚本, 提前安装registry镜像仓库

替换镜像： 我们上面配置的脚本是针对单个模块的，多个模块可以根据 for 循环来实现。

4.验证

1）在 Jenkins 上安装 SSH 插件

安装 SSH 插件的原因是因为，我们这个 Jenkins 是容器安装的，而脚本是在宿主机写的，所以通过远程到宿主机来运行脚本。

2）配置远程主机的用户名和密码

3）创建 Jenkins 私钥凭证（类型选择：SSH Username with private key）

4）配置 Jenkins 流水线

5）修改代码

6）在 Jenkins 上发布

访问应用服务

总结：

通过上面的操作，实现了从git提交代码到发布K8S应用服务的整个CICD流程文章来源地址https://www.toymoban.com/news/detail-453135.html

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