> ## 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 Create a Shared Library for Slack Notification

> Learn to create a Jenkins Shared Library for reusable Slack notifications across multiple pipelines, reducing code duplication and maintenance efforts.

Learn how to extract common Slack notification logic into a reusable Jenkins Shared Library for consistent alerts across multiple pipelines.

## Why Use a Shared Library?

Embedding Slack notification code directly in each `Jenkinsfile` leads to duplicate scripts and maintenance headaches. A Shared Library lets you:

* Centralize notification logic
* Update formats or colors in one place
* Enforce consistent Slack workflows organization-wide

Example of duplicated code in a typical `Jenkinsfile`:

```groovy theme={null}
def slackNotificationMethod(String buildStatus = 'STARTED') {
    buildStatus = buildStatus ?: 'SUCCESS'
    // ... color logic ...
    slackSend(color: color, message: msg)
}
```

## 1. Create the Shared Library Repository

1. In your Git hosting platform (e.g. [Gitea](https://gitea.io), [GitHub](https://github.com)), create a new repository named `shared-libraries` under your organization (`dasher-org`).

<Frame>
  ![The image shows a "New Repository" creation page on Gitea, where the user can select the owner, repository name, and other settings like visibility, description, and templates.](https://kodekloud.com/kk-media/image/upload/v1752871099/notes-assets/images/Certified-Jenkins-Engineer-Demo-Create-a-Shared-Library-for-Slack-Notification/gitea-new-repository-creation.jpg)
</Frame>

2. Initialize and push to `main`:

```bash theme={null}
touch README.md
git init
git checkout -b main
git add README.md
git commit -m "Initialize shared library repository"
git remote add origin http://64.227.187.25:5555/dasher-org/shared-libraries.git
git push -u origin main
```

## 2. Define the Repository Layout

Jenkins Shared Libraries follow this directory structure:

```text theme={null}
(shared-libraries)
├── src
│   └── org
│       └── foo
│           └── Bar.groovy
├── vars
│   ├── foo.groovy
│   └── foo.txt
└── resources
    └── org
        └── foo
            └── bar.json
```

* `src/org/...` holds Groovy classes.
* `vars/` contains global scripts (e.g., `slackNotification.groovy`) and help text.
* `resources/` stores static assets like JSON.

Learn more in the [Jenkins Shared Library Documentation](https://www.jenkins.io/doc/book/pipeline/shared-libraries/).

## 3. Add Slack Notification Logic

Create `vars/slackNotification.groovy`:

<Frame>
  ![The image shows a web interface for a code repository named "shared-libraries" under "dasher-org," with a file path for creating a new file called "slackNotification."](https://kodekloud.com/kk-media/image/upload/v1752871100/notes-assets/images/Certified-Jenkins-Engineer-Demo-Create-a-Shared-Library-for-Slack-Notification/shared-libraries-dasher-org-new-file.jpg)
</Frame>

```groovy theme={null}
// vars/slackNotification.groovy
def call(String buildStatus = 'STARTED') {
    // Default to SUCCESS if unset
    buildStatus = buildStatus ?: 'SUCCESS'

    // Map statuses to Slack colors
    def color = switch (buildStatus) {
        case 'SUCCESS' -> '#47ec05'
        case 'UNSTABLE' -> '#d5ee0d'
        default -> '#ec2805'
    }

    // Construct and send the notification
    def msg = "${buildStatus}: ${env.JOB_NAME} #${env.BUILD_NUMBER}\n${env.BUILD_URL}"
    slackSend(color: color, message: msg)
}
```

<Callout icon="lightbulb" color="#1CB2FE">
  Defining a `call` method lets you invoke `slackNotification()` directly in your pipeline like a built-in step.
</Callout>

### Build Status Color Reference

| Build Status | Slack Color Code |
| ------------ | ---------------- |
| SUCCESS      | `#47ec05`        |
| UNSTABLE     | `#d5ee0d`        |
| Others       | `#ec2805`        |

## 4. Use the Shared Library in Your Pipeline

1. Go to **Manage Jenkins** > **Configure System**.
2. Under **Global Pipeline Libraries**, add:
   * **Name**: `shared-libraries`
   * **Default version**: `main`
   * **Retrieval method**: Modern SCM (Git)

Then in any `Jenkinsfile`:

```groovy theme={null}
@Library('shared-libraries') _
pipeline {
    agent any
    stages {
        stage('Build') {
            steps {
                echo 'Building...'
            }
        }
        stage('Notify') {
            steps {
                // Default status SUCCESS
                slackNotification()
                // Or custom status:
                // slackNotification('FAILURE')
            }
        }
    }
}
```

<Callout icon="triangle-alert" color="#FF6B6B">
  Ensure the Slack Notification plugin is installed and a valid Slack workspace credential is configured under **Manage Jenkins** > **Configure System**.
</Callout>

## Links and References

* [Jenkins Shared Libraries](https://www.jenkins.io/doc/book/pipeline/shared-libraries/)
* [Slack Notification Plugin](https://plugins.jenkins.io/slack/)
* [Jenkins Pipeline Syntax](https://www.jenkins.io/doc/book/pipeline/syntax/)
* [Gitea Documentation](https://docs.gitea.io/)

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