Installing and Deploying Jenkins Master

Selecting an Image

Select a relatively new, stable image from Docker Hub. For this test, select jenkinsci/blueocean, which is bound with all Blue Ocean add-ons and functions. There is no need to install Blue Ocean add-ons separately. For details, see Installing Jenkins.

Preparations

• Before creating a containerized workload, buy a cluster (the cluster must contain at least one node with four vCPUs and 8 GiB memory). For details, see Buying a CCE Cluster.

  The Docker in Docker scenario is required, which is, running the Docker commands in the container. Select the Docker container engine for the node.

• To enable external networks to access the workload, ensure that an elastic IP address (EIP) has been bound to or a load balancer has been configured for at least one node in the cluster.

Installing and Deploying Jenkins on CCE

1. Log in to the CCE console, choose Workloads > Deployments and click Create Workload on the upper right corner.
2. Configure basic workload parameters.
   • Workload Name: jenkins (customizable)
   • Namespace: Select the namespace where Jenkins will be deployed. You can create a namespace.
   • Pods: Set it to 1.

   

3. Configure basic container parameters.
   • Image Name: Enter jenkinsci/blueocean. Select an image version as required. If no version is selected, the latest version will be used by default.
   • CPU Quota: Set Limit to 2 cores.
   • Memory Quota: Set Limit to 2048 MiB.
   • Privileged Container: If Jenkins with a single Master is used, the privileged container must be enabled so that the container can perform operations on the node. Otherwise, you cannot run the Docker commands in the Jenkins Master container.
   Retain the default values for other parameters.

   Figure 1 Basic container parameters
   

4. Click Data Storage and add a persistent storage volume.
   Click Add Volume, select PVC from the drop-down list, and add a storage volume. Enter /var/jenkins_home under Mount Path to mount the storage volume to /var/jenkins_home of the Jenkins container for persistent data storage.

   

   The cloud storage type can be EVS or SFS. If no cloud storage is available, click Create PVC.

   If you select EVS, the AZ of the EVS disk must be the same as that of the node.

   Figure 2 Adding a cloud volume
   

5. Add permissions to the Jenkins container so that related commands can be executed in it.
   1. Ensure that Privileged Container is enabled in 3.
   2. Click Data Storage, click Add Volume, select hostPath, and mount the host path to the corresponding container path.

      Table 1 Mounting path

      Storage Type	Host Path	Mounting Path
      hostPath	/var/run/docker.sock	/var/run/docker.sock
      hostPath	/usr/bin/docker	/usr/bin/docker
      hostPath	/usr/lib64/libltdl.so.7	/usr/lib/x86_64-linux-gnu/libltdl.so.7
      hostPath	/usr/bin/kubectl	/usr/local/bin/kubectl

      After the mounting is complete, the page shown in Figure 3 is displayed.

      Figure 3 Mounting the host paths to the corresponding container paths
      

   3. In Security Context, set User ID to 0 (user root).
      Figure 4 Configuring the user
      

6. Specify the access mode in Service Configuration.

   The Jenkins container image has two ports: 8080 and 50000. Configure them separately. Port 8080 is used for web login, and port 50000 is used for the connection between Master and Agent.

   In this example, two Services are created:

   • LoadBalancer: provides external web access using port 8080. You can also select NodePort to provide external access.

     Set the Service name to jenkins (customizable), the container port to 8080, the access port to 8080, and retain the default values for other parameters.

   • ClusterIP: used by the Agent to connect to the Master. The IP addresses of jenkins-web and jenkins-agent need to be the same. Therefore, port 8080 for web access and port 50000 for agent access are included.

     Set the Service name to agent (customizable), the container port 1 to 8080, the access port 1 to 8080, the container port 2 to 50000, the access port 2 to 50000, and retain the default values for other parameters.

     

     In this example, Agents and the Master are deployed in the same cluster. Therefore, the Agents can use the ClusterIP Service to connect to the Master.

     If Agents need to connect to the Master across clusters or through the public network, select a proper Service type. Note that the IP addresses of Jenkins-web and Jenkins-agent need to be the same. Therefore, ports 8080 and 50000 must be enabled for the IP address connected to jenkins-agent. For addresses used only for web access, enable only the port 8080.

   Figure 5 Adding a Service
   

7. Retain the default settings for Advanced Settings and click Create Workload.
8. Click Back to Deployment List to view the Deployment status. If the workload is in the Running status, the Jenkins application is accessible.

Logging In and Initializing Jenkins

1. On the CCE console, click the name of the target cluster to access the cluster console. Choose Services & Ingresses in the navigation pane. On the Services tab, view the Jenkins access mode.
   Figure 6 Access mode corresponding to port 8080
   

2. Enter EIP:8080 of the load balancer in the browser address box to visit the Jenkins configuration page.

   When you visit the page for the first time, you are prompted to obtain the initial administrator password. You can obtain the password from the Jenkins pod. Before running the following commands, connect to the cluster using kubectl. For details, see Connecting to a Cluster Using kubectl.

   # kubectl get pod -n cicd
   NAME                                     READY   STATUS    RESTARTS   AGE
   jenkins-7c69b6947c-5gvlm                 1/1     Running   0          17m
   # kubectl exec -it jenkins-7c69b6947c-5gvlm -n cicd -- /bin/sh
   # cat /var/jenkins_home/secrets/initialAdminPassword
   b10eabe29a9f427c9b54c01a9c3383ae

3. The system prompts you to select the default recommended add-on and create an administrator upon the first login. After the initial configuration is complete, the Jenkins page is displayed.

   

Modifying the Number of Concurrent Build Jobs

1. On the Jenkins dashboard page, click Manage Jenkins on the left, choose System Configuration > Manage nodes and clouds, and select Configure from the drop-down list of the target node.

   

   

   • You can modify the number of concurrent build jobs on both Master and Agent. The following uses Master as an example.
   • If the Master is used with Agents, you are advised to set the number of concurrent build jobs of Master to 0. That is, all build jobs are performed using Agents. If a single Master is used, you do not need to change the value to 0.

2. Modify the maximum number of concurrent build jobs. In this example, the value is changed to 2. You can change the value as required.