Managing Kubernetes Manifests with Kustomize and Automating Code Review with Gerrit and Jenkins

Gerrit + Jenkins

Background

Our team uses Gerrit for code management and code review. We want to automatically trigger a Jenkins pipeline when a review is submitted and merged. This article records the configuration of the Gerrit Trigger pipeline, without covering server configuration details.

Gerrit Configuration

We can quickly start a Gerrit instance using Docker. The default ports are HTTP 8080 and SSH 29418. The CANONICAL_WEB_URL parameter specifies the server web address.

docker run --name gerrit -itd \
-p 8088:8080 \
-p 29418:29418 \
-e CANONICAL_WEB_URL=http://192.168.1.200:8088 gerritcodereview/gerrit

After the container starts, install any required plugins or skip the step. Log in with the default admin account and create a Jenkins user.

Jenkins User SSH Key

Enter the Jenkins pod, generate an SSH key pair, and note the location of the private key ( /var/jenkins_home/.ssh/id_rsa) and public key ( /var/jenkins_home/.ssh/id_rsa.pub).

[root@zeyang-nuc-service ~]# kubectl exec -it jenkins-6ccf555769-sfdw6 -n devops bash
bash-4.2$ id
uid=1000(jenkins) gid=1000(jenkins) groups=1000(jenkins)
bash-4.2$ ssh-keygen
Generating public/private rsa key pair.
Enter file in which to save the key (/var/jenkins_home/.ssh/id_rsa):
Created directory '/var/jenkins_home/.ssh'.
Enter passphrase (empty for no passphrase):
Enter same passphrase again:
Your identification has been saved in /var/jenkins_home/.ssh/id_rsa.
Your public key has been saved in /var/jenkins_home/.ssh/id_rsa.pub.
SHA256:nGqkSVAUuc2xrGe8Bz/xuWcQ/YVrDISPJux+tCZkJgI jenkins@jenkins-6ccf555769-sfdw6

Copy the content of id_rsa.pub and add it to the Gerrit user configuration (click **ADD**).

cat /var/jenkins_home/.ssh/id_rsa.pub

Gerrit Permissions

Add the Jenkins user to the Non‑interactive Users group (BROWSE → Groups → Non‑Interactive Users → Members).

Create a repository and set basic permissions:

refs/* : read Non-interactive Users
refs/heads/* : Label Code-Review Non-interactive Users

Create a group named Event Streaming Users (Gerrit 2.7+) and add the Jenkins user to it.

Enable the Stream Events capability for the group in

All‑Projects → Access → Global Capabilities → Stream Events

:

allow Event Streaming Users

Jenkins Configuration

Install the **Gerrit Hook** plugin in Jenkins. After installation, the Gerrit icon appears in the system management UI.

Add the **Gerrit Trigger** build step to the pipeline job. If you encounter the error "Connection error : com.jcraft.jsch.JSchException: Auth fail", it is usually caused by an SSH‑key mismatch.

Create a Code Review

Push a change to Gerrit using the special ref refs/for/master:

[root@zeyang-nuc-service devops]# echo 123 >test.txt
[root@zeyang-nuc-service devops]# git add .
[root@zeyang-nuc-service devops]# git commit -m "init"
[root@zeyang-nuc-service devops]# git push origin HEAD:refs/for/master
Username for 'http://192.168.1.200:8088': admin
Password for 'http://[email protected]:8088':
... (push output) ...
remote: SUCCESS
remote:   http://192.168.1.200:8088/c/devops/+/21 init [NEW]

After the review is approved and merged, Gerrit automatically triggers the Jenkins pipeline.

Pipeline as Code

// Pipeline parameters
String BRANCH_NAME = "${env.GERRIT_BRANCH}"
String PROJECT_NAME = "devops"
String PROJECT_URL = "http://192.168.1.200:8088/devops"
currentBuild.description = "Trigger By ${BRANCH_NAME}"

pipeline {
    agent {
        node { label "build" }
    }
    options { skipDefaultCheckout() }
    triggers {
        gerrit customUrl: '',
               gerritProjects: [[branches: [[compareType: 'ANT', pattern: '**']],
                                 compareType: 'PLAIN',
                                 pattern: "${PROJECT_NAME}"]],
               serverName: 'devops',
               triggerOnEvents: [changeMerged()]
    }
    stages {
        stage('GetCode') {
            steps {
                echo "========executing GetCode========"
                checkout([$class: 'GitSCM', branches: [[name: "${BRANCH_NAME}"]],
                          userRemoteConfigs: [[url: "${PROJECT_URL}"]]])
            }
        }
    }
    post {
        always { echo "========always========"; cleanWs() }
        success { echo "========pipeline executed successfully ========" }
        failure { echo "========pipeline execution failed========" }
    }
}

With this configuration, any change that passes Gerrit review automatically triggers the Jenkins pipeline, enabling a smooth CI/CD workflow.