Kubernetes CI／CD（2）

本章节通过在Jenkins创建一个kubernetes云环境，动态的在kubernetes集群中创建pod完成pipeline的构建流程，关于直接在宿主机上搭建Jenkins集群的可参照Kubernetes CI／CD（1）

部署Jenkins

下载Jenkins对应的镜像
```
docker pull jenkins/jenkins:2.221
```

将jenkins镜像上传到自己的私有镜像仓库中

docker tag jenkins/jenkins:2.221 192.168.0.107/k8s/jenkins:2.221

docker push 	192.168.0.107/k8s/jenkins:2.221

编写启动Jenkins的yml文件

cat > jenkins.yml << EOF

kind: PersistentVolume

apiVersion: v1

metadata:

  name: jenkins

  labels:

    type: local

    app: jenkins

spec:

  capacity:

    storage: 10Gi

  accessModes:

    - ReadWriteOnce

  hostPath:

    path: /opt/k8s/yml/jenkins/data

---

kind: PersistentVolumeClaim

apiVersion: v1

metadata:

  name: jenkins-claim

spec:

  accessModes:

    - ReadWriteOnce

  resources:

    requests:

      storage: 10Gi

---

apiVersion: v1

kind: ServiceAccount

metadata:

  name: jenkins

  namespace: default

automountServiceAccountToken: true

---

apiVersion: rbac.authorization.k8s.io/v1

kind: ClusterRoleBinding

metadata:

  name: Jenkins-cluster-admin

roleRef:

  apiGroup: rbac.authorization.k8s.io

  kind: ClusterRole

  name: cluster-admin

subjects:

- kind: ServiceAccount

  name: jenkins

  namespace: default

---

apiVersion: v1

kind: Service

metadata:

  name: jenkins

  labels:

    app: jenkins

spec:

  ports:

    - port: 80

      targetPort: 8080

      nodePort: 8888

      name: jenkins

    - port: 50000

      targetPort: 50000

      nodePort: 50000

      name: agent

  selector:

    app: jenkins

    tier: jenkins

  type: NodePort

---

apiVersion: apps/v1

kind: Deployment

metadata:

  name: jenkins

  labels:

    app: jenkins

spec:

  strategy:

    type: Recreate

  selector:

    matchLabels:

      app: jenkins

      tier: jenkins

  template:

    metadata:

      labels:

        app: jenkins

        tier: jenkins

    spec:

      serviceAccountName: jenkins

      containers:

      - image: 192.168.0.107/k8s/jenkins:2.221

        imagePullPolicy: IfNotPresent

        name: jenkins

        securityContext:

          privileged: true

          runAsUser: 0

        volumeMounts:

        - name: kubeconfig

          mountPath: /var/jenkins_home/.kube

        - name: docker

          mountPath: /var/run/docker.sock

        - name: docker-bin

          mountPath: /usr/bin/docker

        - name: jenkins-persistent-storage

          mountPath: /var/jenkins_home

        ports:

        - containerPort: 8080

          name: jenkins

        - containerPort: 50000

        	name: agent

      volumes:

      - name: kubeconfig

        emptyDir: {}

      - name: docker

        hostPath:

          path: /var/run/docker.sock

      - name: docker-bin

        hostPath:

          path: /opt/k8s/bin/docker

      - name: jenkins-persistent-storage

        persistentVolumeClaim:

          claimName: jenkins-claim

EOF

安装 kubernetes相关插件

kubernetes-cd

kubernetes-client-api

kubernetes-credentials

kubernetes

配置kubernetes云（配置详情官方网站kubernetes-plugin)

新加一个Cloud

在Jenkins界面执行
Manage Jenkins -> Manage Nodes and Clouds -> Configure Clouds -> Add a new Cloud
配置cloud，点击Kubernetes Cloud details
- Kubernetes 地址：指定要连接的k8s集群API地址，因为我们master是在k8s集群中启动的，所以此处可以直接用https://kubernetes.default.svc.cluster.local，其中kubernetes是k8s集群给我们启动的一个service，内部会把对他的访问转发给API server，如果Jenkins不在k8s集群中，或者想要启动的构建pod和master不是一个集群，这个地方就需要相应的k8s集群地址
- 凭据：访问k8s集群的认证凭证，我们启动Jenkins集群时同时创建了Service account，并赋给了Jenkins容器，所以这个地方可以直接创建一个service count类型的凭据,如果是访问其他集群，需要用服务证书key来配置
配置好后点击:连接测试,正常的话会出现Connection test successful的提示
配置Jenkins相关信息（主要是agent和master通信的信息）
- Jenkins 地址：连接jenkins master的地址，因为我们jenkins对应的service启动节点是80，所以这个地方就去掉了端口号，并且service也启动了50000端口映射到容器的50000，所以直接配置成http://jenkins

构建一个简单的流水线验证cloud的构建功能

在Jenkins界面新建一个item，名称hello-pipeline-cloud，类型选择:流水线(pipeline)
编辑pipeline部分
```
podTemplate(cloud: "kubernetes") {

    node(POD_LABEL) {

            stage('Run shell') {

                sh 'echo hello world'

            }

    }

}
```
- cloud: "kubernetes"，指定执行的云环境，默认是kubernetes，所以这个地方可以省略，当有多个云环境或者我们创建的cloud名称不是kubernetes则需要明确指定
- POD_LABEL 是在1.17.0版本后引入的一个新特性，可以自动对创建的pod进行打标签

执行构建

首先我们可以在要执行的k8s集群上执行如下命令观察执行构建过程中k8s云给我做了什么事

kubectl get pod -w

在Jenkins界面选择刚创建的工程，点击 Build Now

对应的集群的输出

root@master:/opt/k8s/yml/jenkins# kubectl get pod -w

NAME                       READY   STATUS    RESTARTS   AGE

jenkins-68d8b54c45-gshvp   1/1     Running   0          60m

hello-pipeline-cloud-9-7n3c4-8stzj-n8g6v   0/1     Pending   0          0s

hello-pipeline-cloud-9-7n3c4-8stzj-n8g6v   0/1     Pending   0          0s

hello-pipeline-cloud-9-7n3c4-8stzj-n8g6v   0/1     ContainerCreating   0          0s

hello-pipeline-cloud-9-7n3c4-8stzj-n8g6v   1/1     Running             0          1s

hello-pipeline-cloud-9-7n3c4-8stzj-n8g6v   1/1     Terminating         0          7s

hello-pipeline-cloud-9-7n3c4-8stzj-n8g6v   0/1     Terminating         0          8s

hello-pipeline-cloud-9-7n3c4-8stzj-n8g6v   0/1     Terminating         0          9s

hello-pipeline-cloud-9-7n3c4-8stzj-n8g6v   0/1     Terminating         0          9s

可以看到k8s集群给我们创建了一个新的pod：hello-pipeline-cloud-9-7n3c4-8stzj-n8g6v，构建完成后会自动把这个pod停掉

Jenkins构建的日志

Started by user admin

Running in Durability level: MAX_SURVIVABILITY

[Pipeline] Start of Pipeline

[Pipeline] podTemplate

[Pipeline] {

[Pipeline] node

Still waiting to schedule task

All nodes of label ‘hello-pipeline-cloud_9-7n3c4’ are offline

Created Pod: hello-pipeline-cloud-9-7n3c4-8stzj-n8g6v in namespace default

Agent hello-pipeline-cloud-9-7n3c4-8stzj-n8g6v is provisioned from template hello-pipeline-cloud_9-7n3c4-8stzj

---

apiVersion: "v1"

kind: "Pod"

metadata:

  annotations:

    buildUrl: "http://jenkins/job/hello-pipeline-cloud/9/"

    runUrl: "job/hello-pipeline-cloud/9/"

  labels:

    jenkins: "slave"

    jenkins/label: "hello-pipeline-cloud_9-7n3c4"

  name: "hello-pipeline-cloud-9-7n3c4-8stzj-n8g6v"

spec:

  containers:

  - env:

    - name: "JENKINS_SECRET"

      value: "********"

    - name: "JENKINS_AGENT_NAME"

      value: "hello-pipeline-cloud-9-7n3c4-8stzj-n8g6v"

    - name: "JENKINS_NAME"

      value: "hello-pipeline-cloud-9-7n3c4-8stzj-n8g6v"

    - name: "JENKINS_AGENT_WORKDIR"

      value: "/home/jenkins/agent"

    - name: "JENKINS_URL"

      value: "http://jenkins/"

    image: "jenkins/jnlp-slave:3.35-5-alpine"

    name: "jnlp"

    volumeMounts:

    - mountPath: "/home/jenkins/agent"

      name: "workspace-volume"

      readOnly: false

  nodeSelector:

    beta.kubernetes.io/os: "linux"

  restartPolicy: "Never"

  securityContext: {}

  volumes:

  - emptyDir:

      medium: ""

    name: "workspace-volume"

Running on hello-pipeline-cloud-9-7n3c4-8stzj-n8g6v in /home/jenkins/agent/workspace/hello-pipeline-cloud

[Pipeline] {

[Pipeline] stage

[Pipeline] { (Run shell)

[Pipeline] sh

+ echo hello world

hello world

[Pipeline] }

[Pipeline] // stage

[Pipeline] }

[Pipeline] // node

[Pipeline] }

[Pipeline] // podTemplate

[Pipeline] End of Pipeline

Finished: SUCCESS

从日志中可以看到k8s集群采用默认的pod模版给我启动了一个pod，并且把我们的构建内容sh 'echo hello world'在pod对应的容器中执行了

如果默认的模版不能满足我们的要求（比如在内网工作，对应的image想用我们自己私有仓库中的镜像可以重写name是jnlp的容器模版）后面一个例子，我们会重写这个模版，并在我们自定义的容器中执行我们的构建

构建自定义podtemplage

在Jenkins界面新建一个item，名称hello-pipeline-selfpodtemplate，类型选择:流水线(pipeline)

编辑pipeline部分

Kubernetes CI／CD（2）-LMLPHP

podTemplate(yaml: """

apiVersion: v1

kind: Pod

metadata:

  labels:

    app: busybox

spec:

  containers:

  - name: busybox

    image: 192.168.0.107/k8s/busybox:latest

    command:

    - cat

    tty: true

"""

,containers: [containerTemplate(name: 'jnlp', image: '192.168.0.107/jenkins/jnlp-slave:3.35-5-alpine')]

,cloud: "kubernetes") {

    node(POD_LABEL) {

      container('busybox') {

        sh "hostname"

      }

    }

}

yaml 通过这个字段，我们定义了一个自己的podtemplate，容器名称是busybox，并在后面使用
containers的containerTemplate，我们重写了jnlp容器启动的镜像名称。jnlp镜像必须启动，他要和jenkins master通信，来告知构建状态，并且不能配置其它容器模版的名称为jnlp，否则会造成构建一直不会结束
具体的构建流程，我们通过container('busybox')指定了构建要执行的容器，这个地方我们可以根据要构建的类型，配置maven、gradle、docker等各种构建环境来配置不同的podtemplate以此满足不同的构建需求，这也是用云环境进行构建的优势

同样，我们看下k8s集群的pod创建情况



root@master:/opt/k8s/yml/jenkins# kubectl get pod -w

NAME                       READY   STATUS    RESTARTS   AGE

jenkins-68d8b54c45-gshvp   1/1     Running   0          83m

hello-pipeline-selfpodtemplate-6-ch89k-0v48m-xxsqw   0/2     Pending   0          0s

hello-pipeline-selfpodtemplate-6-ch89k-0v48m-xxsqw   0/2     Pending   0          0s

hello-pipeline-selfpodtemplate-6-ch89k-0v48m-xxsqw   0/2     ContainerCreating   0          0s

hello-pipeline-selfpodtemplate-6-ch89k-0v48m-xxsqw   2/2     Running             0          2s

hello-pipeline-selfpodtemplate-6-ch89k-0v48m-xxsqw   2/2     Terminating         0          7s

看到这次k8s集群创建的pod包含了两个容器，如果我们describe这个pod可以看到里面是我们指定的容器

Jenkins日志

Started by user admin

Running in Durability level: MAX_SURVIVABILITY

[Pipeline] Start of Pipeline

[Pipeline] podTemplate

[Pipeline] {

[Pipeline] node

Created Pod: hello-pipeline-selfpodtemplate-6-ch89k-0v48m-xxsqw in namespace default

Still waiting to schedule task

Waiting for next available executor on ‘hello-pipeline-selfpodtemplate-6-ch89k-0v48m-xxsqw’

Agent hello-pipeline-selfpodtemplate-6-ch89k-0v48m-xxsqw is provisioned from template hello-pipeline-selfpodtemplate_6-ch89k-0v48m

---

apiVersion: "v1"

kind: "Pod"

metadata:

  annotations:

    buildUrl: "http://jenkins/job/hello-pipeline-selfpodtemplate/6/"

    runUrl: "job/hello-pipeline-selfpodtemplate/6/"

  labels:

    app: "busybox"

    jenkins: "slave"

    jenkins/label: "hello-pipeline-selfpodtemplate_6-ch89k"

  name: "hello-pipeline-selfpodtemplate-6-ch89k-0v48m-xxsqw"

spec:

  containers:

  - command:

    - "cat"

    image: "192.168.0.107/k8s/busybox:latest"

    name: "busybox"

    tty: true

    volumeMounts:

    - mountPath: "/home/jenkins/agent"

      name: "workspace-volume"

      readOnly: false

  - env:

    - name: "JENKINS_SECRET"

      value: "********"

    - name: "JENKINS_AGENT_NAME"

      value: "hello-pipeline-selfpodtemplate-6-ch89k-0v48m-xxsqw"

    - name: "JENKINS_NAME"

      value: "hello-pipeline-selfpodtemplate-6-ch89k-0v48m-xxsqw"

    - name: "JENKINS_AGENT_WORKDIR"

      value: "/home/jenkins/agent"

    - name: "JENKINS_URL"

      value: "http://jenkins/"

    image: "192.168.0.107/jenkins/jnlp-slave:3.35-5-alpine"

    imagePullPolicy: "IfNotPresent"

    name: "jnlp"

    resources:

      limits: {}

      requests: {}

    securityContext:

      privileged: false

    tty: false

    volumeMounts:

    - mountPath: "/home/jenkins/agent"

      name: "workspace-volume"

      readOnly: false

  nodeSelector:

    beta.kubernetes.io/os: "linux"

  restartPolicy: "Never"

  securityContext: {}

  volumes:

  - emptyDir:

      medium: ""

    name: "workspace-volume"

Running on hello-pipeline-selfpodtemplate-6-ch89k-0v48m-xxsqw in /home/jenkins/agent/workspace/hello-pipeline-selfpodtemplate

[Pipeline] {

[Pipeline] container

[Pipeline] {

[Pipeline] sh

+ hostname

hello-pipeline-selfpodtemplate-6-ch89k-0v48m-xxsqw

[Pipeline] }

[Pipeline] // container

[Pipeline] }

[Pipeline] // node

[Pipeline] }

[Pipeline] // podTemplate

[Pipeline] End of Pipeline

Finished: SUCCESS

可以看到jnlp对应的镜像名称变成我们指定的镜像
pod template 的内容默认是打印出来的，可以通过配置不显示 podTemplate(showRawYaml:false,...)

遇到问题

追加kubernetes service account凭据时报错
```
HTTP ERROR 403 No valid crumb was included in the request
```
简单解决方法，在Configure Global Security配置页面去掉CSRF Protection