> ## Documentation Index
> Fetch the complete documentation index at: https://notes.kodekloud.com/llms.txt
> Use this file to discover all available pages before exploring further.
# Demo Slack Notification Legacy App
> Learn to integrate Slack with Jenkins for automated build notifications, enhancing alerts with rich formatting and job details.
In this lesson, you’ll learn how to integrate Slack with Jenkins so that every build event sends a notification to your Slack channel. We’ll begin with basic alerts and then enhance them using Slack’s attachments and rich formatting.
Slack is a leading collaboration platform that delivers real-time notifications to your team. By connecting Jenkins to Slack, you can automatically post build statuses—SUCCESS, FAILURE, or ABORTED—along with job details and a link to the build.
Key notification fields:
* Build status
* Job name and build number
* Direct link to build results
We’ll cover:
1. Install & verify the Slack Notification Plugin
2. Create a Slack workspace & channel
3. Add Jenkins CI to Slack
4. Configure Jenkins global settings
5. Define a shared library for notifications
6. Implement the notification logic
7. Integrate in your Jenkinsfile
8. Test the integration
***
## 1. Install and Verify the Slack Notification Plugin
Install the official [Slack Notification Plugin](https://plugins.jenkins.io/slack/) on your Jenkins instance. We’re using version **2.48**.
> **Note: Compatibility**\
> Verify plugin compatibility with your Jenkins LTS/core version. Check the [plugin’s changelog](https://plugins.jenkins.io/slack/) before upgrading.
***
## 2. Create a Slack Workspace and Channel
1. Sign in to your Slack workspace (the free plan works).
2. Create a new channel named **#jenkins** (or any name you prefer). This is where Jenkins will post notifications.
> **Note: Channel Permissions**\
> Ensure Jenkins has posting permissions. Workspace admins can adjust these under **Settings & administration**.
***
## 3. Add the Jenkins CI App to Slack
1. In Slack, click your workspace name → **Settings & administration** → **Manage apps**.
2. Search for **Jenkins** in the App Directory and select **Jenkins CI**.
3. Click **Add to Slack** and follow the prompts.
4. Choose the **#jenkins** channel and authorize the app.
5. Copy the **Integration Token** provided.
6. Note your **Team Subdomain** (e.g., `devsecops-k8s`) and **Token** for Jenkins configuration.
***
## 4. Configure Jenkins Global Settings
1. In Jenkins, go to **Manage Jenkins** → **Configure System** and scroll to the **Slack** section.
2. Enter your **Team Domain** and click **Add** under **Credentials**.
3. Choose **Secret Text**, paste your Slack token, and save.
4. Click **Test Connection** to verify Jenkins can post to Slack. You should receive a confirmation message in your channel.
> **Warning: Protect Your Token**\
> Never expose your Slack token in logs or code—always store it as a Jenkins credential.
***
## 5. Define a Shared Library for Notifications
Centralize your Slack notification logic by creating a Jenkins Shared Library in a Git repo:
```text theme={null}
(root)
± src
| ± org
| ± foo
| ± Bar.groovy # org.foo.Bar class
± vars
| ± sendNotification.groovy # wrapper for slackSend
| ± sendNotification.txt # help text for the global var
± resources
| ± org
| ± foo
| ± Bar.json # static helper data
```
### 5.1 Configure the Global Pipeline Library
1. In Jenkins, go to **Manage Jenkins** → **Configure System** → **Global Pipeline Libraries**.
2. Click **Add** and configure:
* **Name**: `slack`
* **Default Version**: `main`
* **Retrieval Method**: Git
* **Project Repository**: ``
3. Save the configuration.
***
## 6. Implement the Notification Logic
Create `vars/sendNotification.groovy` in your shared library:
```groovy theme={null}
def call(String buildStatus = 'STARTED') {
// Fallback to SUCCESS if undefined
buildStatus = buildStatus ?: 'SUCCESS'
// Choose color by status
def color = (buildStatus == 'SUCCESS') ? '#47ec05' :
(buildStatus == 'UNSTABLE') ? '#5eeded' : '#ec2805'
// Build the message
def msg = "*${buildStatus}* `${env.JOB_NAME}` #${env.BUILD_NUMBER}\n${env.BUILD_URL}"
// Send to Slack
slackSend(color: color, message: msg)
}
```
Table: Build status → Slack color
| Build Status | Hex Color |
| ------------ | --------- |
| SUCCESS | #47ec05 |
| UNSTABLE | #5eeded |
| FAILURE | #ec2805 |
***
## 7. Integrate in Your Jenkinsfile
Atop your `Jenkinsfile`, load the library and invoke `sendNotification` in the `post` block:
```groovy theme={null}
@Library('slack') _
pipeline {
agent any
stages {
stage('Build') {
steps {
sh 'mvn clean package -DskipTests=true'
archive 'target/*.jar'
}
}
// ... other stages ...
}
post {
always {
// Send Slack notification with the final build result
sendNotification currentBuild.result
}
}
}
```
> **Note: Customizing Notifications**\
> You can extend `sendNotification` to include Slack attachments, fields, and action buttons for richer messages.
***
## 8. Test the Integration
1. Commit and push your shared library and `Jenkinsfile`.
2. Trigger a new build in Jenkins.
3. Review the build in Jenkins:
4. Check Slack’s **#jenkins** channel for a green “SUCCESS” notification:
5. To simulate a failure, add `sh 'exit 1'` in a build step, push, and confirm a red “FAILURE” alert.
***
## Next Steps
You’ve set up basic Slack notifications with build status, job name, ID, and URL. Coming up:
* Slack attachments with fields and images
* Dynamic channels based on branch or environment
* Interactive message buttons and menus
Stay tuned for more advanced Slack–Jenkins integrations!
***
## Links and References
* [Slack API Documentation](https://api.slack.com/)
* [Slack Notification Plugin for Jenkins](https://plugins.jenkins.io/slack/)
* [Jenkins Shared Library Guide](https://www.jenkins.io/doc/book/pipeline/shared-libraries/)
* [Jenkins Pipeline Syntax](https://www.jenkins.io/doc/book/pipeline/syntax/)
* [Slack App Directory](https://slack.com/apps)