[SOLVED] How to Trigger Another Job from a Jenkins Pipeline with GitHub Org Plugin? - jenkins

[SOLVED] How to Trigger Another Job from a Jenkins Pipeline Using the GitHub Org Plugin

In this guide, we will learn how to trigger another job from a Jenkins pipeline. We will use the GitHub Org Plugin for this. This step is important to automate our workflows. It helps us connect different jobs in our CI/CD pipeline. If we want to improve our Jenkins setup or make our project workflows easier, this tutorial will show us all the steps we need.

In this chapter, we will talk about these solutions:

Part 1 - Setting Up the GitHub Org Plugin: We will set up the GitHub Org Plugin for Jenkins. This helps us manage many repositories.
Part 2 - Creating the Jenkins Pipeline: We will build a Jenkins pipeline that works with our GitHub projects.
Part 3 - Using the Build Step to Trigger Another Job: We will use the Jenkins build step to start another job in our pipeline.
Part 4 - Passing Parameters to the Triggered Job: We will learn how to send parameters to the job we trigger.
Part 5 - Handling Job Dependencies: We will make sure that job dependencies are managed well in Jenkins.
Part 6 - Testing the Triggered Job Execution: We will check that the triggered jobs run as they should and meet our needs.
Frequently Asked Questions: We will answer common questions about triggering jobs in Jenkins.

By learning how to trigger another job from a Jenkins pipeline with the GitHub Org Plugin, we will improve our continuous integration. It will also help our development teams work better together. For more information on related topics, check out how to trigger Jenkins build or how to call Jenkins build from another job. Let’s start!

Part 1 - Setting Up the GitHub Org Plugin

To set up the GitHub Org Plugin in Jenkins, we can follow these easy steps.

Install the GitHub Org Plugin:
- First, go to Manage Jenkins and then Manage Plugins.
- In the Available tab, we search for GitHub Organization Plugin.
- We select the plugin and click Install without restart.
Configure GitHub Credentials:
- Next, go to Manage Jenkins and then Manage Credentials.
- We pick the right domain, which can be global.
- Click on (global) and then Add Credentials.
- Choose Kind as GitHub Personal Access Token.
- We enter the token and a unique ID, then save it.
Set Up GitHub Server:
- Now, go to Manage Jenkins and then Configure System.
- Scroll down to the GitHub section.
- Click Add GitHub Server and give it a name.
- Select the credentials we made before.
- Test the connection to make sure it works.
Create a New Multibranch Pipeline:
- From the Jenkins dashboard, we click on New Item.
- We name our job and select Multibranch Pipeline, then click OK.
- In the job configuration, under Branch Sources, we click Add source and select GitHub.
- Enter our repository URL and select the credentials.
- Configure any other settings we need.
Set Up Webhook in GitHub:
- Now, go to the settings of our GitHub repository.
- Under Webhooks, we click Add webhook.
- Here, we enter our Jenkins URL followed by /github-webhook/ as the payload URL.
- We set the content type to application/json.
- Choose to trigger the webhook on Just the push event.
- Finally, we click Add webhook.

Now we have set up the GitHub Org Plugin in Jenkins. This lets us trigger jobs based on events in our GitHub organization. For more help, we can check the Jenkins build triggers documentation.

Part 2 - Creating the Jenkins Pipeline

To create a Jenkins pipeline that starts another job using the GitHub Org Plugin, we can follow these steps:

Create a New Pipeline Job:
- Open Jenkins. Click on “New Item.”
- Type a name for your pipeline. Choose “Pipeline” as the job type. Then click “OK.”
Define the Pipeline:
- In the pipeline settings, scroll to the “Pipeline” part.
- Use this example pipeline script to set up the pipeline:

pipeline {
    agent any
    stages {
        stage('Clone Repository') {
            steps {
                git url: 'https://github.com/your-org/your-repo.git'
            }
        }
        stage('Build') {
            steps {
                echo 'Building the project...'
                // Add your build steps here
            }
        }
        stage('Trigger Another Job') {
            steps {
                build job: 'another-job-name', wait: false
            }
        }
    }
}

Configure GitHub Org Plugin:
- Make sure you have the GitHub Org Plugin installed.
- Go to “Manage Jenkins” then “Configure System.” Set up the GitHub config with your credentials.
Set Up Webhook in GitHub:
- Go to your GitHub repo settings.
- Under “Webhooks,” add a new webhook that points to your Jenkins (like http://your-jenkins-url/github-webhook/).
Save and Build:
- Save the pipeline settings.
- Start the pipeline manually or through a GitHub event to test.

By doing these steps, we will create a Jenkins pipeline that can start another job using the GitHub Org Plugin. For more info on how to start Jenkins builds, check out how to trigger Jenkins builds.

Part 3 - Using the build step to Trigger Another Job

We can trigger another Jenkins job from our pipeline by using the build step in our Jenkinsfile. This helps us start a downstream job. We can also pass parameters to it if we want.

Basic Triggering of Another Job

Here is a simple example to trigger a job called downstream-job:

pipeline {
    agent any
    stages {
        stage('Trigger Downstream Job') {
            steps {
                build job: 'downstream-job'
            }
        }
    }
}

Triggering with Parameters

If we want to pass parameters to the downstream job, we can use the parameters option. Here is an example:

pipeline {
    agent any
    stages {
        stage('Trigger Downstream Job with Parameters') {
            steps {
                build job: 'downstream-job',
                      parameters: [
                          string(name: 'PARAM1', value: 'value1'),
                          booleanParam(name: 'PARAM2', value: true)
                      ]
            }
        }
    }
}

Handling Job Dependencies

When we trigger jobs, we must manage dependencies well. We need to make sure that the upstream job finished successfully before we trigger the downstream job. We can use the wait parameter to wait for the downstream job to finish.

pipeline {
    agent any
    stages {
        stage('Trigger and Wait for Downstream Job') {
            steps {
                script {
                    def result = build job: 'downstream-job', wait: true
                    echo "Downstream job result: ${result.result}"
                }
            }
        }
    }
}

Triggering Jobs Conditionally

We can also trigger jobs based on the results of earlier stages. Here is how we can do this:

pipeline {
    agent any
    stages {
        stage('Main Job') {
            steps {
                script {
                    def jobResult = sh(script: 'run_some_command', returnStatus: true)
                    if (jobResult == 0) {
                        build job: 'downstream-job'
                    } else {
                        echo 'Main job failed, downstream job will not be triggered.'
                    }
                }
            }
        }
    }
}

For more details on triggering jobs, we can check how to trigger Jenkins builds.

By following these steps, we can use the build step to trigger another job in our Jenkins pipeline. This way, our CI/CD process stays efficient and organized.

Part 4 - Passing Parameters to the Triggered Job

We can pass parameters to a triggered job in a Jenkins pipeline with the GitHub Org Plugin. To do this, we use the build step and the parameters option. This helps us send specific values that the downstream job can use.

Example Pipeline Code

Here is an example of how we can pass parameters:

pipeline {
    agent any
    stages {
        stage('Trigger Job') {
            steps {
                script {
                    def jobParameters = [
                        string(name: 'PARAM1', value: 'value1'),
                        string(name: 'PARAM2', value: 'value2')
                    ]
                    build job: 'downstream-job-name', parameters: jobParameters
                }
            }
        }
    }
}

Explanation of the Code

build job: 'downstream-job-name': This tells us the name of the job we want to trigger.
parameters: jobParameters: Here, we pass the parameters to the downstream job. We can define many parameters using types like string, boolean, file, and more.

Using Environment Variables

If we want to pass environment variables as parameters, we can do it like this:

build job: 'downstream-job-name', parameters: [
    string(name: 'BUILD_ENV', value: env.BUILD_ENV)
]

Important Notes

We need to make sure that the downstream job can accept parameters. We do this by enabling “This project is parameterized” in the job settings.
We can check the Jenkins documentation for more details on parameter types and settings.
For more complex use cases, we can use the GitHub Org Plugin to set triggers based on GitHub events.

Part 5 - Handling Job Dependencies

We can manage job dependencies in Jenkins when we trigger another job from a Jenkins Pipeline using the GitHub Org Plugin. We use the build step with the right settings. This helps the triggered job to wait until its dependencies finish.

Define Job Dependencies: We need to know which jobs must run before our current job. We can do this by naming the required jobs in our pipeline script.

Use the build Step: The build step helps us to trigger another job and wait for it to finish. Here is a simple example of how to do this:

pipeline {
    agent any
    stages {
        stage('Trigger Dependent Job') {
            steps {
                script {
                    def jobResult = build job: 'DependentJobName', propagate: true, wait: true
                    if (jobResult.result != 'SUCCESS') {
                        error "Dependent job failed: ${jobResult.result}"
                    }
                }
            }
        }
        stage('Continue with Current Job') {
            steps {
                echo 'Continuing with the current job...'
            }
        }
    }
}

Propagate Failures: When we set propagate: true, if the triggered job fails, our current job will fail too. This is very important for keeping our CI/CD pipeline safe.

Using Parameters: If the dependent job needs parameters, we can give them like this:

def jobResult = build job: 'DependentJobName', parameters: [
    string(name: 'PARAM1', value: 'value1'),
    string(name: 'PARAM2', value: 'value2')
], propagate: true, wait: true

Handling Multiple Dependencies: If we have more than one job to trigger, we can link them like this:

pipeline {
    agent any
    stages {
        stage('Trigger Jobs') {
            steps {
                script {
                    def job1Result = build job: 'Job1', propagate: true, wait: true
                    def job2Result = build job: 'Job2', propagate: true, wait: true
                }
            }
        }
    }
}

Error Handling: We can use try-catch blocks to manage errors better when we trigger jobs:

try {
    def jobResult = build job: 'DependentJobName', propagate: true, wait: true
} catch (Exception e) {
    echo "Job failed: ${e.message}"
    currentBuild.result = 'FAILURE'
}

By following these steps, we can handle job dependencies in our Jenkins Pipeline well. For more details on how to trigger jobs, check our guide on how to trigger Jenkins builds.

Part 6 - Testing the Triggered Job Execution

To make sure the triggered job runs right from our Jenkins pipeline with the GitHub Org Plugin, we can follow these easy steps for testing.

Create a Test Job: First, we need to set up a new Jenkins job. This job will be triggered by the main pipeline. Let’s use a simple script to check if it runs well.

pipeline {
    agent any
    stages {
        stage('Test Execution') {
            steps {
                script {
                    echo 'Test job executed successfully!'
                }
            }
        }
    }
}

Configure the Main Pipeline: Next, we should check that the main Jenkins pipeline has the build step ready to trigger the test job. We can use the build step to call the test job.

pipeline {
    agent any
    stages {
        stage('Trigger Test Job') {
            steps {
                build job: 'TestJob', wait: true
            }
        }
    }
}

Run the Main Pipeline: Now, we can trigger the main pipeline. We can do this manually or use a GitHub webhook. Let’s watch the console output. We need to make sure that the test job is triggered and finishes successfully.
Check Job Logs: After it runs, we should look at the logs for both the main pipeline and the triggered job. We want to check for any errors. We should find the message “Test job executed successfully!” in the console output of the test job.
Validate Results: Depending on what the job does, we need to check that we got the expected results. This could be artifacts, notifications, or other outputs.

For more details on how to trigger Jenkins jobs well, please look at How to Trigger Jenkins Build. Testing our pipeline execution is very important. It helps us make sure everything runs smoothly, especially with job dependencies.

Frequently Asked Questions

1. How can we trigger a Jenkins job from another job using the GitHub Org Plugin?

To trigger another Jenkins job from our current pipeline with the GitHub Org Plugin, we can use the build step in our Jenkinsfile. This lets us say the job name and send parameters if we need. For more details, we can look at our article on how to trigger Jenkins builds.

2. What are the necessary permissions to trigger a job in Jenkins?

When we trigger another job in Jenkins through a pipeline, we need to make sure the user or service account has the right permissions to run builds on the target job. This usually means having the ‘Build’ permission. For more on how to manage Jenkins permissions, we can check our guide on how to authenticate Jenkins CI.

3. Can we pass parameters to the triggered job in Jenkins?

Yes, we can pass parameters to a Jenkins job that another job triggers. We use the build step in our pipeline script and say the parameters we want to send. For more info, we can see our article on how to trigger Jenkins builds with parameters.

4. How do we handle job dependencies in Jenkins?

We can manage job dependencies in Jenkins by using the build step to trigger jobs that depend on others. This helps to make sure jobs run in the right order. We can also look at tools like Jenkins Pipeline for complex workflows. For more details, we can refer to our article on how to fix Jenkins pipeline issues.

5. What should we do to test if the triggered job works correctly?

To test a triggered job, we can run the parent job and watch the output. We should have logging turned on to catch any errors or problems when the triggered job runs. For more tips on troubleshooting, we can check our article on how to fix error messages in Jenkins.

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