Kubernetes （K8s） 是一个开源系统，用于自动化部署、扩展、 以及容器化应用程序的管理。

在 Kubernetes 上部署Jenkins

1. 创建命名空间

2. 创建具有 Kubernetes 管理员权限的服务帐户。

3. 在 Pod 重新启动时为持久 Jenkins 数据创建本地持久卷

4. 创建部署YAML并进行部署。

5. 创建服务YAML并部署它。

---

1.安装git软件

[root@k8smaster ~]# yum install git -y

2.下载相关的yaml文件

[root@k8smaster ~]# git clone https://github.com/scriptcamp/kubernetes-jenkins
[root@k8smaster ~]# cd kubernetes-jenkins/
[root@k8smaster kubernetes-jenkins]# ls
deployment.yaml  namespace.yaml  serviceAccount.yaml  service.yaml  volume.yaml

3.创建命名空间

[root@k8smaster kubernetes-jenkins]# cat namespace.yaml 
apiVersion: v1
kind: Namespace
metadata:
  name: devops-tools
[root@k8smaster kubernetes-jenkins]# kubectl apply -f namespace.yaml 
namespace/devops-tools created
[root@k8smaster kubernetes-jenkins]# kubectl get ns
NAME              STATUS   AGE
default           Active   13d
devops-tools      Active   6s
ingress-nginx     Active   2d4h
kube-node-lease   Active   13d
kube-public       Active   13d
kube-system       Active   13d

4.创建服务账号，集群角色，绑定

[root@k8smaster kubernetes-jenkins]# cat serviceAccount.yaml 
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRole
metadata:
  name: jenkins-admin
rules:
  - apiGroups: [""]
    resources: ["*"]
    verbs: ["*"]

---
apiVersion: v1
kind: ServiceAccount
metadata:
  name: jenkins-admin
  namespace: devops-tools

---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
  name: jenkins-admin
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: ClusterRole
  name: jenkins-admin
subjects:
- kind: ServiceAccount
  name: jenkins-admin
[root@k8smaster kubernetes-jenkins]# kubectl apply -f serviceAccount.yaml 
clusterrole.rbac.authorization.k8s.io/jenkins-admin created
serviceaccount/jenkins-admin created
clusterrolebinding.rbac.authorization.k8s.io/jenkins-admin created

5.创建卷，用来存放数据
 

[root@k8smaster kubernetes-jenkins]# cat volume.yaml 
kind: StorageClass
apiVersion: storage.k8s.io/v1
metadata:
  name: local-storage
provisioner: kubernetes.io/no-provisioner
volumeBindingMode: WaitForFirstConsumer

---
apiVersion: v1
kind: PersistentVolume
metadata:
  name: jenkins-pv-volume
  labels:
    type: local
spec:
  storageClassName: local-storage
  claimRef:
    name: jenkins-pv-claim
    namespace: devops-tools
  capacity:
    storage: 10Gi
  accessModes:
    - ReadWriteOnce
  local:
    path: /mnt
  nodeAffinity:
    required:
      nodeSelectorTerms:
      - matchExpressions:
        - key: kubernetes.io/hostname
          operator: In
          values:
          - k8snode1   # 需要修改为k8s里的node节点的名字

---
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: jenkins-pv-claim
  namespace: devops-tools
spec:
  storageClassName: local-storage
  accessModes:
    - ReadWriteOnce
  resources:
    requests:
      storage: 3Gi
[root@k8smaster kubernetes-jenkins]# kubectl apply -f volume.yaml 
storageclass.storage.k8s.io/local-storage unchanged
persistentvolume/jenkins-pv-volume unchanged
persistentvolumeclaim/jenkins-pv-claim unchanged
[root@k8snode1 mnt]# kubectl get pv
NAME                CAPACITY   ACCESS MODES   RECLAIM POLICY   STATUS   CLAIM                           STORAGECLASS    REASON   AGE
jenkins-pv-volume   10Gi       RWO            Retain           Bound    devops-tools/jenkins-pv-claim   local-storage            3d1h
sc-nginx-pv         10Gi       RWX            Retain           Bound    default/sc-nginx-pvc            nfs                      5d16h
task-pv-volume      10Gi       RWO            Retain           Bound    default/task-pv-claim           manual                   5d17h
[root@k8snode1 mnt]# kubectl describe pv jenkins-pv-volume
Name:              jenkins-pv-volume
Labels:            type=local
Annotations:       <none>
Finalizers:        [kubernetes.io/pv-protection]
StorageClass:      local-storage
Status:            Bound
Claim:             devops-tools/jenkins-pv-claim
Reclaim Policy:    Retain
Access Modes:      RWO
VolumeMode:        Filesystem
Capacity:          10Gi
Node Affinity:     
  Required Terms:  
    Term 0:        kubernetes.io/hostname in [k8snode1]
Message:           
Source:
    Type:  LocalVolume (a persistent volume backed by local storage on a node)
    Path:  /mnt
Events:    <none>

6.部署Jenkins

[root@k8smaster kubernetes-jenkins]# cat deployment.yaml 
apiVersion: apps/v1
kind: Deployment
metadata:
  name: jenkins
  namespace: devops-tools
spec:
  replicas: 1
  selector:
    matchLabels:
      app: jenkins-server
  template:
    metadata:
      labels:
        app: jenkins-server
    spec:
      securityContext:
            fsGroup: 1000 
            runAsUser: 1000
      serviceAccountName: jenkins-admin
      containers:
        - name: jenkins
          image: jenkins/jenkins:lts
          imagePullPolicy: IfNotPresent
          resources:
            limits:
              memory: "2Gi"
              cpu: "1000m"
            requests:
              memory: "500Mi"
              cpu: "500m"
          ports:
            - name: httpport
              containerPort: 8080
            - name: jnlpport
              containerPort: 50000
          livenessProbe:
            httpGet:
              path: "/login"
              port: 8080
            initialDelaySeconds: 90
            periodSeconds: 10
            timeoutSeconds: 5
            failureThreshold: 5
          readinessProbe:
            httpGet:
              path: "/login"
              port: 8080
            initialDelaySeconds: 60
            periodSeconds: 10
            timeoutSeconds: 5
            failureThreshold: 3
          volumeMounts:
            - name: jenkins-data
              mountPath: /var/jenkins_home         
      volumes:
        - name: jenkins-data
          persistentVolumeClaim:
              claimName: jenkins-pv-claim

建议删除之前使用docker容器安装的Jenkins
[root@k8snode1 ~]# docker stop sc-jenkins-1
sc-jenkins-1

[root@k8smaster kubernetes-jenkins]# kubectl apply -f deployment.yaml 
deployment.apps/jenkins configured
[root@k8smaster kubernetes-jenkins]# kubectl get deploy -n devops-tools
NAME      READY   UP-TO-DATE   AVAILABLE   AGE
jenkins   1/1     1            1           3d1h
[root@k8smaster kubernetes-jenkins]# kubectl get pod -n devops-tools
NAME                       READY   STATUS    RESTARTS   AGE
jenkins-85fcfbb869-zlvvz   1/1     Running   2          3d1h

7.启动服务发布Jenkins的pod

[root@k8smaster kubernetes-jenkins]# cat service.yaml 
apiVersion: v1
kind: Service
metadata:
  name: jenkins-service
  namespace: devops-tools
  annotations:
      prometheus.io/scrape: 'true'
      prometheus.io/path:   /
      prometheus.io/port:   '8080'
spec:
  selector: 
    app: jenkins-server
  type: NodePort  
  ports:
    - port: 8080
      targetPort: 8080
      nodePort: 32000
[root@k8smaster kubernetes-jenkins]# kubectl apply -f service.yaml 
[root@k8smaster kubernetes-jenkins]# kubectl get svc -n devops-tools
NAME              TYPE       CLUSTER-IP      EXTERNAL-IP   PORT(S)          AGE
jenkins-service   NodePort   10.108.132.26   <none>        8080:32000/TCP   3d1h

8.在Windows机器上访问Jenkins，宿主机ip+端口号

http://192.168.102.136:32000/login?from=%2F

9.进入pod里获取登录的密码

[root@k8smaster kubernetes-jenkins]# kubectl exec -it -n devops-tools jenkins-85fcfbb869-zlvvz -- bash
jenkins@jenkins-85fcfbb869-zlvvz:/$ cat /var/jenkins_home/secrets/initialAdminPassword
160a061f20f247f29512a85fbb8815af