基于jenkins+k8s实现devops

1、背景

由于jenkins运行在k8s上能够更好的利用动态agent进行构建。所以写了个部署教程，亲测无坑

2、部署

1、创建ns
kubectl create namespace devops

2、kubectl apply -f jenkins.yml

apiVersion: v1
kind: ServiceAccount
metadata:
  name: jenkins
  namespace: devops
---
kind: ClusterRole
apiVersion: rbac.authorization.k8s.io/v1
metadata:
  name: jenkins
rules:
  - apiGroups: ["extensions", "apps"]
    resources: ["deployments", "ingresses"]
    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", "watch"]
  - apiGroups: [""]
    resources: ["pods/exec"]
    verbs: ["create", "delete", "get", "list", "patch", "update", "watch"]
  - apiGroups: [""]
    resources: ["pods/log", "events"]
    verbs: ["get", "list", "watch"]
  - apiGroups: [""]
    resources: ["secrets"]
    verbs: ["get"]
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
  name: jenkins
  namespace: devops
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: ClusterRole
  name: jenkins
subjects:
  - kind: ServiceAccount
    name: jenkins
    namespace: devops
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: jenkins
  namespace: devops
spec:
  selector:
    matchLabels:
      app: jenkins
  template:
    metadata:
      labels:
        app: jenkins
    spec:
      serviceAccount: jenkins
      initContainers:
        - name: fix-permissions
          image: busybox:1.35.0
          command: ["sh", "-c", "chown -R 1000:1000 /var/jenkins_home"]
          securityContext:
            privileged: true
          volumeMounts:
            - name: jenkinshome
              mountPath: /var/jenkins_home
      containers:
        - name: jenkins
          image: jenkins/jenkins:2.414.1-lts-jdk11
          imagePullPolicy: IfNotPresent
          env:
            - name: JAVA_OPTS
              value: -Dhudson.model.DownloadService.noSignatureCheck=true
          ports:
            - containerPort: 8080
              name: web
              protocol: TCP
            - containerPort: 50000
              name: agent
              protocol: TCP
          readinessProbe:
            httpGet:
              path: /login
              port: 8080
            initialDelaySeconds: 60
            timeoutSeconds: 5
            failureThreshold: 12
          volumeMounts:
            - name: jenkinshome
              mountPath: /var/jenkins_home
            - name: localtime
              mountPath: /etc/localtime  
      volumes:
        - name: jenkinshome
          hostPath:
            path: /opt/jenkins/jenkins_data
        - name: localtime
          hostPath:
            path: /etc/localtime
---
apiVersion: v1
kind: Service
metadata:
  name: jenkins
  namespace: devops
  labels:
    app: jenkins
spec:
  selector:
    app: jenkins
  ports:
    - name: web
      port: 8080
      targetPort: web
    - name: agent
      port: 50000
      targetPort: agent
---
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: jenkins
  namespace: devops
spec:
  ingressClassName: nginx
  rules:
    - host: jenkins.k8s.com
      http:
        paths:
          - path: /
            pathType: Prefix
            backend:
              service:
                name: jenkins
                port:
                  name: web

注意：镜像建议使用最新版本，因为jenkin平台默认提供了最新的插件，且无法选择版本，所以如果jenkins版本过低会导致插件不兼容问题

3、本地电脑配置host解析后，就可以用域名访问

4、查看pod日志获取初始化密码，也可以查看/opt/jenkins/jenkins_data/secrets/initialAdminPassword

5、安装必要插件
中文插件： Localization: Chinese
pipeline插件：Pipeline
k8s插件： Kubernetes
代码库管理插件：Git

6、配置k8s连接信息

填写 以下内容 ，然后点击测试。
k8s地址 ：https://kubernetes.default.svc.cluster.local
命名空间：devops
jenkins地址：http://jenkins.devops.svc.cluster.local:8080

由于之前部署的时候已经给jenkins用户访问k8s 的devops命名空间的权限，所以这里不需要配置kubeconfig认证也可直接访问

3、编写一条pipeline

这里用一个java项目的ci过程作为案例

def createVersion() {
    // 定义一个版本号作为当次构建的版本，输出结果 20191210175842_69
    return new Date().format('yyyyMMddHHmmss') + "_${env.BUILD_ID}"
}

pipeline{
    agent{
        kubernetes{
          defaultContainer 'maven'
          yaml '''
apiVersion: v1
kind: Pod
spec:
  containers:
    - name: maven
      image: maven:3.8.1-jdk-8
      command: ["sleep"]
      args: ["99d"]
    - name: docker
      image: docker
      command: ["sleep"]
      args: ["99d"]
      volumeMounts:
        - mountPath: /var/run/docker.sock
          name: docker-socket
  volumes:
    - name: docker-socket
      hostPath:
        path: /var/run/docker.sock
'''
        }
    }
    environment {
        tag = createVersion()
    }
    stages{
        stage("pull code"){
          steps{
            script{
              git 'https://gitee.com/uuei/java-devops-demo.git'
            }
          }
        }
        stage("mvn"){
          steps{
            script{
              sh 'mvn clean package'
            }
            container('docker') {
              script {
              sh 'docker build -t java-demo:${tag} .'
            }
        }
          }
        }
    }
}