本文详细讲解了k8s安装jenkins实验的几个步骤。
第一步，创建命名空间

kubectl create namespace jenkins

第二步，创建权限，因为 jenkins 后面需要能够动态创建 slave，因此它必须具备一些权限 jenkins-rbac.yaml

apiVersion: v1
kind: ServiceAccount
metadata:
  name: jenkins
  namespace: jenkins

---
kind: ClusterRole
apiVersion: rbac.authorization.k8s.io/v1beta1
metadata:
  name: jenkins
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","watch"]
  - apiGroups: [""]
    resources: ["pods/exec"]
    verbs: ["create","delete","get","list","patch","update","watch"]
  - apiGroups: [""]
    resources: ["pods/log"]
    verbs: ["get","list","watch"]
  - apiGroups: [""]
    resources: ["secrets"]
    verbs: ["get"]

---
apiVersion: rbac.authorization.k8s.io/v1beta1
kind: ClusterRoleBinding
metadata:
  name: jenkins
  namespace: jenkins
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: ClusterRole
  name: jenkins
subjects:
  - kind: ServiceAccount
    name: jenkins
    namespace: jenkins

kubectl apply -f jenkins-rbac.yaml
第三步，创建创建pv用于数剧挂载 pvc.yaml
该步骤使用的是NFS方式，NFS安装配置可以参考：https://www.jianshu.com/p/c36e06f9c9ed

apiVersion: v1
kind: PersistentVolume
metadata:
  name: jenkins-pv
spec:
  capacity:
    storage: 20Gi
  accessModes:
  - ReadWriteMany
  persistentVolumeReclaimPolicy: Delete
  nfs:
    server: 192.168.54.53
    path: /k8s_data/jenkins

---
kind: PersistentVolumeClaim
apiVersion: v1
metadata:
  name: jenkins-pvc
  namespace: jenkins
spec:
  accessModes:
    - ReadWriteMany
  resources:
    requests:
      storage: 20Gi

kubectl apply -f pvc.yaml
第四步，部署jenkins-deployment.yaml
这步如果部署不成功，可以尝试使用kuboard界面进行部署

---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: jenkins
  namespace: jenkins
spec:
  template:
    metadata:
      labels:
        app: jenkins
    spec:
      terminationGracePeriodSeconds: 10
      serviceAccount: jenkins
      containers:
      - name: jenkins
        image: jenkins/jenkins:lts
        imagePullPolicy: IfNotPresent
        ports:
        - containerPort: 8080
          name: web
          protocol: TCP
        - containerPort: 50000
          name: agent
          protocol: TCP
        resources:
          limits:
            cpu: 1000m
            memory: 1Gi
          requests:
            cpu: 500m
            memory: 512Mi
        livenessProbe:
          httpGet:
            path: /login
            port: 8080
          initialDelaySeconds: 60
          timeoutSeconds: 5
          failureThreshold: 12
        readinessProbe:
          httpGet:
            path: /login
            port: 8080
          initialDelaySeconds: 60
          timeoutSeconds: 5
          failureThreshold: 12
        volumeMounts:
        - name: jenkinshome
          subPath: jenkins
          mountPath: /var/jenkins_home
        env:
        - name: LIMITS_MEMORY
          valueFrom:
            resourceFieldRef:
              resource: limits.memory
              divisor: 1Mi
        - name: JAVA_OPTS
          value: -Xmx$(LIMITS_MEMORY)m -XshowSettings:vm -Dhudson.slaves.NodeProvisioner.initialDelay=0 -Dhudson.slaves.NodeProvisioner.MARGIN=50 -Dhudson.slaves.NodeProvisioner.MARGIN0=0.85 -Duser.timezone=Asia/Shanghai
      securityContext:
        fsGroup: 1000
      volumes:
      - name: jenkinshome
        persistentVolumeClaim:
          claimName: jenkins-pvc

---
apiVersion: v1
kind: Service
metadata:
  name: jenkins
  namespace: jenkins
  labels:
    app: jenkins
spec:
  selector:
    app: jenkins
  type: NodePort
  ports:
  - name: web
    port: 8080
    targetPort: web
    nodePort: 30002
  - name: agent
    port: 50000
    targetPort: agent

第一次登陆的密码在日志里面可以看见，然后就是安装他推荐的插件，安装完成后就是配置jenkins,在jenkins配置里面配置好你所需的配置，根据自己情况而定，比如我们项目使用grade我就要配置gradle等等。

排错信息

touch: cannot touch '/var/jenkins_home/copy_reference_file.log': Permission denied
Can not write to /var/jenkins_home/copy_reference_file.log. Wrong volume permissions?

很明显是nfs挂载文件没有权限，加权限就行，因为Jenkins默认的用户ID是1000，所以使用下面命令用1000给配置权限。这里可以在启动的时候指定ID为0（表示root） ,因该就不会有这个报错。

chown -R 1000 /opt/nfs/jenkins

重新执行第四步就可以。