How to Set Up a Jenkins Pipeline Triggered by GitHub Webhook to Run Ansible Playbooks

Prerequisites

• Jenkins installed and running

• Jenkins server accessible from GitHub (publicly or via tunneling)

• GitHub repository with your Ansible playbooks

• Jenkins plugins installed: Git, Pipeline, GitHub Integration

• SSH key (.pem file) configured with correct permissions for your target servers.

Step 1: Create a Jenkins Pipeline Job

1. Open Jenkins dashboard.

2. Click New Item.

3. Enter a name for your pipeline, e.g., ansible-deployment-pipeline.

4. Select Pipeline and click OK.

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Step 2: Configure Pipeline Parameters and Environment Variables

• Add parameters like Pipeline_name and Ansible_playbook (select from available playbooks).

• Set environment variables for your GitHub repo URL and Ansible playbook directory.

Example snippet in your Jenkinsfile:

environment {
    GIT_REPO_URL = 'https://github.com/yourusername/your-ansible-repo.git'
    ANSIBLE_DIR = "/var/lib/jenkins/workspace/${params.Pipeline_name}/ansible/"
}
parameters {
    string(name: "Pipeline_name", defaultValue: "", description: "Enter pipeline name")
    choice(name: 'Ansible_playbook', choices: ['nginx-install.yml', 'nginx-uninstall.yml', 'reboot.yml', 'update-kernel.yml'], description: 'Select Ansible playbook')
}

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Step 3: Set Up Git Checkout Stage

Add a stage in your Jenkinsfile to checkout code from GitHub:

stage('Checkout SCM') {
    steps {
        checkout([$class: 'GitSCM', branches: [[name: '*/main']], userRemoteConfigs: [[url: env.GIT_REPO_URL]]])
    }
}

Make sure to replace main with your branch name.

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Step 4: Set File Permissions (Optional)

If your Ansible playbook needs access to an SSH key, modify its permissions:

stage('Modify pem file permission') {
    steps {
        dir("${env.ANSIBLE_DIR}") {
            sh "sudo chmod 400 yourkey.pem"
        }
    }
}

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Step 5: Execute Ansible Playbook

Run the selected playbook using the Jenkins pipeline:

stage('Execute the pipeline') {
    steps {
        dir("${env.ANSIBLE_DIR}") {
            sh "sudo ansible-playbook -i hosts ${params.Ansible_playbook} -b"
        }
    }
}

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Step 6: Configure GitHub Webhook

1. In your GitHub repo, go to Settings > Webhooks.

2. Click Add webhook.

3. Enter your Jenkins server webhook URL:

    http://<jenkins-server-url>/github-webhook/
   

4. Set Content type to application/json.

5. Select Just the push event.

6. Click Add webhook.

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Step 7: Configure Jenkins to Listen to Webhook Events

1. In your Jenkins pipeline job, go to Configure > Build Triggers.

2. Check GitHub hook trigger for GITScm polling.

3. Save the configuration.

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Step 8: Test the Pipeline

• Push a commit to the GitHub repository branch.

• The webhook will trigger Jenkins.

• Jenkins will run the pipeline and execute the Ansible playbook.