Skip to main content
In this guide, you’ll enhance the Jenkinsfile in the solar-system repository to send Slack notifications based on build outcomes. By the end, you’ll have a reusable Groovy helper and a DRY pipeline that alerts your team of successes, instabilities, and failures.

​
1. Create a Feature Branch

Start by branching off from main: 
git checkout -b feature/enabling-slack
Switched to a new branch 'feature/enabling-slack'

​
2. Generate the Slack Step

Open Pipeline Syntax in Jenkins:
  1. Select Slack Send.
  2. Configure your channel (e.g., #dasher-notifications).
  3. Set a default message and a hex color for “Build Started.”
The image shows a Jenkins Pipeline Syntax page where a user is configuring a Slack message to be sent to a specific channel named "dasher-notifications."
You can pick a hex code to reflect status:
The image shows a Jenkins pipeline syntax configuration screen for sending Slack messages, with fields for channel, message, and color settings. The color is set to a hex code, and there are options for advanced settings and workspace credentials.
Pipeline syntax will produce: 
slackSend botUser: true,
          channel: '#dasher-notifications',
          color: '#439FE0',
          message: "Build Started: ${env.JOB_NAME} ${env.BUILD_NUMBER}"
Ensure you have configured your Slack App and credentials in Jenkins Manage Credentials before using slackSend.

​
3. Why Reuse Is Better

Adding identical slackSend calls under every stage’s post block quickly becomes unwieldy: 
pipeline {
  /* ... */
  stages {
    stage('Upload - AWS S3') {
      steps { /* ... */ }
      post {
        success {
          slackSend botUser: true,
                    channel: '#dasher-notifications',
                    color: '#47ec05',
                    message: "Upload S3 succeeded: ${env.BUILD_NUMBER}"
        }
        failure {
          slackSend botUser: true,
                    channel: '#dasher-notifications',
                    color: '#ec2805',
                    message: "Upload S3 failed: ${env.BUILD_NUMBER}"
        }
      }
    }
    // more stages...
  }
}
The image shows a Jenkins interface with options for setting post-stage or build conditions, including checkboxes for various build statuses.

​
4. Define a Reusable Slack Method

At the top of your Jenkinsfile, add: 
def slackNotification(String buildStatus = 'STARTED') {
    buildStatus = buildStatus ?: 'SUCCESS'

    // Map status to color
    def color = buildStatus == 'SUCCESS'  ? '#47ec05' :
                buildStatus == 'UNSTABLE' ? '#d5ee0d' :
                                            '#ec2805'

    // Construct message
    def msg = "${buildStatus}: ${env.JOB_NAME} #${env.BUILD_NUMBER}\n${env.BUILD_URL}"
    slackSend color: color, message: msg
}

​
Build Status Color Mapping

Build StatusHex Color
SUCCESS#47ec05
UNSTABLE#d5ee0d
FAILURE#ec2805

​
5. Update the Pipeline

Use a single post { always { ... } } block: 
pipeline {
    agent any
    tools {
        // e.g., nodejs '12.x'
    }
    stages {
        stage('Installing Dependencies') {
            steps {
                sh 'npm install --no-audit'
            }
        }
        stage('Code Coverage') {
            steps {
                catchError(buildResult: 'SUCCESS', message: 'Coverage step failed but allowed') {
                    sh 'npm run coverage'
                }
            }
        }
        // additional stages...
    }
    post {
        always {
            slackNotification(currentBuild.result)
        }
        cleanup {
            sh 'rm -rf solar-system-gitops-argocd'
        }
        junit allowEmptyResults: true, testResults: 'test-results.xml'
    }
}
Commit and push: 
git add Jenkinsfile
git commit -m "feat: enable Slack notifications"
git push -u origin feature/enabling-slack
Trigger a build to see the consolidated Slack notification:
The image shows a Jenkins pipeline interface for a project named "solar-system," displaying various stages of the build process, including dependency scanning, unit testing, and deployment. Each stage is marked with a status indicator, and the integration testing stage is highlighted.

​
6. Demonstrate Failure

Add a failing step to confirm a red alert: 
pipeline {
    agent any
    stages {
        stage('Fail Fast') {
            steps {
                sh 'echo "Simulating failure"; exit 1'
            }
        }
    }
    post {
        always {
            slackNotification(currentBuild.result)
        }
    }
}
Push and rebuild. The Slack notification color should switch to red on failure.
Never hardcode sensitive tokens in your Jenkinsfile. Use Jenkins Credentials Binding for secure handling.

​
7. Next Steps

To reuse slackNotification across multiple repositories, extract it into a Shared Library. This centralizes common pipeline logic and keeps your Jenkinsfile lean.

Watch Video

Practice Lab