Deploy Jenkins in an ASK cluster and build an application delivery pipeline

Deploy Jenkins

1. Run the following command to download the Jenkins package:

   git clone https://github.com/AliyunContainerService/jenkins-on-serverless.git
   cd jenkins-on-serverless

2. Store the jenkins_home directory in persistent storage.
   ASK clusters do not support Alibaba Cloud disks. If you require persistent storage, you can mount an nfs volume to the jenkins_home directory. You must modify the serverless-k8s-jenkins-deploy.yaml file to uncomment the following lines and set Network File System (NFS) parameters:

   #volumeMounts:
           #  - mountPath: /var/jenkins_home
           #    name: jenkins-home
         .....
         #volumes:
         #  - name: jenkins-home
         #    nfs:
         #      path: /
         #      server:

3. Run the following command to deploy Jenkins:

   kubectl apply -f serverless-k8s-jenkins-deploy.yaml

4. Log on to Jenkins.
   1. Log on to the ACK console.
   2. In the left-side navigation pane of the ACK console, click Clusters.
   3. On the Clusters page, find the cluster that you want to manage and click the name of the cluster or click Details in the Actions column. The details page of the cluster appears.
   4. Select Jenkins and click its external endpoint to log on to Jenkins.
      
   5. On the Jenkins logon page, enter the username and password. The default username and password are both admin.
      Notice To ensure system security, change the password after you log on to Jenkins.
5. Configure the settings on the Getting Started page.
   1. On the Getting Started page, click Install suggested plugins.
   2. After the plug-ins are installed, click Save and Finish in the Instance Configuration section of the Getting Started page.
   3. Click Start using Jenkins.
6. Obtain the Secret that contains a token.
   1. Run the following command to query the token:

      kubectl get secret

      Expected output:

      NAME                         TYPE                                  DATA   AGE
      ack-jenkins-sa-token-q****   kubernetes.io/service-account-token   3      28m
      default-token-b****          kubernetes.io/service-account-token   3      27h

   2. Run the following command to obtain the Secret named ack-jenkins-sa-token-q****:

      kubectl get secret ack-jenkins-sa-token-q**** -o jsonpath={.data.token} |base64 -d

      Expected output:

      sdgdrh****

7. Create a credential of the Secret text type.
   1. In the left-side navigation pane of the Jenkins dashboard, click Manage Jenkins.
   2. On the Manage Jenkins page, click Manage Nodes and Clouds in the System Configuration section.
   3. In the left-side navigation pane of the Nodes page, click Configure Clouds.
   4. On the Configure Clouds page, click Kubernetes Cloud details....
   5. In the Credentials field, choose Add > Jenkins.
   6. In the Jenkins Credentials Provider: Jenkins dialog box, add a credential of the Secret text type.
      The following table describes the credential parameters.

      Parameter	Description
      Domain	The domain of the credential. Default value: Global credentials (unrestricted).
      Kind	The kind of the credential. In this example, Secret text is selected.
      Scope	The scope of the credential. Valid values: Global and System. In this example, Global (Jenkins, nodes, items, all child items, etc) is selected.
      Secret	The Secret of the credential. In this example, the Secret obtained from the previous step is entered.
      ID	The name of the credential. In this example, ask-jenkins-token is entered.
      Description	The description of the credential.

   7. Click Add.
8. On the Configure Clouds page, set the required parameters. For more information, see Configure Kubernetes Cloud.
   1. Set the Kubernetes address, set Credentials to ask-jenkins-token, and then click Connection test to check the connectivity between Jenkins and the cluster.
   2. Set the Jenkins address and Jenkins channel parameters.
   3. Click Save.
9. Build demo-pipeline and access the application.
   1. On the Jenkins homepage, click the icon to the right of demo-pipeline.
      
   2. Modify the build parameters based on the information of your image repository. In this example, the branch of the source code repository is master and the image is registry.cn-beijing.aliyuncs.com/ack-cicd/ack-jenkins-demo:latest.
      
   3. Click Build.
      Test the connectivity between the Jenkins master and the Jenkins slave pod that is dynamically allocated by the Kubernetes cluster.

      After you click Build, Jenkins dynamically creates a slave pod from the Kubernetes cluster to run the build job. For more information about the sample application code, see jenkins-demo-GitHub or jenkins-demo-haoshuwei.

   4. Go to the Status page. If the build is successful, it indicates that Jenkins runs as normal on Kubernetes.