Pull Request Slack Notifier

A GitHub Action to send a message to a Slack channel when an event (opened, reopened, merged, closed, commented, review commented, review approved or review dismissed) occurs on a pull request.

This package has two different techniques to send a message to Slack:

1. Send a message via a Slack app to post to a specific channel (use an existing custom app or create a new one).
2. Send a message via a Slack Incoming Webhook URL (use an existing custom app or create a new one).

The recommended way to use this action is with the Slack app.

Techniques

Technique 1: Slack App

By creating a new Slack app or using an existing one, this approach allows your GitHub Actions job to post a message in a Slack channel by utilizing the Slack Web API.

Setup

• Create a Slack App for your workspace (alternatively use an existing app you have already created and installed).
• Add chat.write and reactions:write (optional) bot scope under OAuth & Permissions.
• Install the app to your workspace.
• Copy the app's Bot User OAuth Token from the OAuth & Permissions page and add it as a secret in your repo settings named SLACK_BOT_TOKEN.
• Copy the channel ID is displayed in the browser URL and add it as a secret in your repo settings named SLACK_CHANNEL_ID. For example: https://app.slack.com/client/TXXXXXXXXXX/DXXXXXXXXXX, channel ID is DXXXXXXXXXX.
• Invite the bot user into the channel you wish to post messages to (you will type a message /invite @bot_user_name).

See more details.

Usage

You can use this action after any other action. Here is a simple example setup of this action:

1. Create a .github/workflows/notify-pull-request-slack.yml file in your GitHub repo.
2. Add the following code to the notify-pull-request-slack.yml file.

For a pull request is opened, reopened, merged or closed

name: Notify Pull Request Slack

on:
  pull_request:
    types:
      - opened
      - reopened
      - closed

jobs:
  notify:
    runs-on: ubuntu-latest
    steps:
      - uses: daint2git/pull-request-slack-notifier@v1
        with:
          slack-bot-token: ${{ secrets.SLACK_BOT_TOKEN }}
          slack-channel-id: ${{ secrets.SLACK_CHANNEL_ID }}
          user-mapping: |
            {
              "GitHub username 1": "Slack member ID 1",
              "GitHub username 2": "Slack member ID 2"
            }

For a pull request is commented

name: Notify Pull Request Slack

on:
  issue_comment:
    types:
      - created
      - edited

jobs:
  notify:
    runs-on: ubuntu-latest
    steps:
      - uses: daint2git/pull-request-slack-notifier@v1
        with:
          slack-bot-token: ${{ secrets.SLACK_BOT_TOKEN }}
          slack-channel-id: ${{ secrets.SLACK_CHANNEL_ID }}
          user-mapping: |
            {
              "GitHub username 1": "Slack member ID 1",
              "GitHub username 2": "Slack member ID 2"
            }

For a pull request is review commented, review approved or review dismissed

name: Notify Pull Request Slack

on:
  pull_request_review:
    types:
      - submitted
      - edited
      - dismissed

jobs:
  notify:
    runs-on: ubuntu-latest
    steps:
      - uses: daint2git/pull-request-slack-notifier@v1
        with:
          slack-bot-token: ${{ secrets.SLACK_BOT_TOKEN }}
          slack-channel-id: ${{ secrets.SLACK_CHANNEL_ID }}
          user-mapping: |
            {
              "GitHub username 1": "Slack member ID 1",
              "GitHub username 2": "Slack member ID 2"
            }

Note that you can completely combine them together.

Technique 2: Slack Incoming Webhook

By creating a new Slack app or using an existing one, this approach allows your GitHub Actions job to post a message to a Slack channel by utilizing Slack Incoming Webhooks.

Setup

• Create a Slack App for your workspace (alternatively use an existing app you have already created and installed).
• Add the incoming-webhook bot scope under OAuth & Permissions.
• Install the app to your workspace (you will select a channel to notify).
• Activate and create a new webhook under Incoming Webhooks.
• Copy the Webhook URL from the Webhook you just generated add it as a secret in your repo settings named SLACK_WEBHOOK_URL.

See more details.

Usage

You can use this action after any other action. Here is a simple example setup of this action:

1. Create a .github/workflows/notify-pull-request-slack.yml file in your GitHub repo.
2. Add the following code to the notify-pull-request-slack.yml file.

For a pull request is opened, reopened, merged or closed

name: Notify Pull Request Slack

on:
  pull_request:
    types:
      - opened
      - reopened
      - closed

jobs:
  notify:
    runs-on: ubuntu-latest
    steps:
      - uses: daint2git/pull-request-slack-notifier@v1
        with:
          slack-webhook-url: ${{ secrets.SLACK_WEBHOOK_URL }}
          user-mapping: |
            {
              "GitHub username 1": "Slack member ID 1",
              "GitHub username 2": "Slack member ID 2"
            }

For a pull request is commented

name: Notify Pull Request Slack

on:
  issue_comment:
    types:
      - created
      - edited

jobs:
  notify:
    runs-on: ubuntu-latest
    steps:
      - uses: daint2git/pull-request-slack-notifier@v1
        with:
          slack-webhook-url: ${{ secrets.SLACK_WEBHOOK_URL }}
          user-mapping: |
            {
              "GitHub username 1": "Slack member ID 1",
              "GitHub username 2": "Slack member ID 2"
            }

For a pull request is review commented, review approved or review dismissed

name: Notify Pull Request Slack

on:
  pull_request_review:
    types:
      - submitted
      - edited
      - dismissed

jobs:
  notify:
    runs-on: ubuntu-latest
    steps:
      - uses: daint2git/pull-request-slack-notifier@v1
        with:
          slack-webhook-url: ${{ secrets.SLACK_WEBHOOK_URL }}
          user-mapping: |
            {
              "GitHub username 1": "Slack member ID 1",
              "GitHub username 2": "Slack member ID 2"
            }

Note that you can completely combine them together.

Inputs

Name	Required	Default	Purpose
github-token	false	github.token	The GitHub token used to create an authenticated client. By default, this action uses the github.token input to get pull request information in your workflow
slack-bot-token	false		Slack bot user OAuth token generated by Slack
slack-channel-id	false		Slack channel ID where the message will be posted. The slack-channel-id input is required when the slack-bot-token input is provided
slack-webhook-url	false		Slack Incoming Webhook URL generated by Slack
user-mapping	false	{}	Mapping between GitHub username and Slack member ID. How to get a Slack Member ID from a workspace in Slack. Note that the Member ID is workspace specific

Note that you need to provide at least one slack-bot-token input or slack-webhook-url input to run this action.

Troubleshooting

To enable runner diagnostic logging set the ACTIONS_RUNNER_DEBUG secret to true.

To enable step debug logging set the ACTIONS_STEP_DEBUG secret to true.

See more details

References

• https://github.com/marketplace/actions/slack-send
• https://github.com/marketplace/actions/slack-notify
• https://github.com/marketplace/actions/slack-github-actions-slack-integration
• https://api.slack.com/messaging/sending
• https://api.slack.com/messaging/webhooks
• https://api.slack.com/web
• https://github.com/hmcts/github-slack-user-mappings
• https://docs.github.com/en/actions/creating-actions/creating-a-javascript-action
• https://docs.github.com/en/actions/using-workflows/events-that-trigger-workflows
• https://docs.github.com/en/developers/webhooks-and-events/webhooks/webhook-events-and-payloads

License

This Action is distributed under the terms of the MIT license, see LICENSE for details.