semantic-release-slack-bot

semantic-release plugin to get release notifications on slack from a slack bot

Step	Description
success	Send a slack message to notify of a new release.
fail	Send a slack message to notify of a failed release.

Install

Add the plugin to your npm-project:

$ npm install semantic-release-slack-bot -D

Requirements

As per the new release of semantic-release library version 20, the library is requiring the use of Node v18, which we need to comply as well to use keep the repo updated with it's latest feature. More information can be found here.

Slack App/Webhook Usage

The corresponding slack app has to be installed in your slack workspace as well. Follow the instructions under configuration for more information.

The plugin can be configured in the semantic-release configuration file:

{
  "plugins": [
    "@semantic-release/commit-analyzer",
    "@semantic-release/release-notes-generator",
    [
      "semantic-release-slack-bot",
      {
        "notifyOnSuccess": false,
        "notifyOnFail": false,
        "slackWebhook": "https://my-webhook.com",
        "branchesConfig": [
          {
            "pattern": "lts/*",
            "notifyOnFail": true
          },
          {
            "pattern": "master1",
            "notifyOnSuccess": true,
            "notifyOnFail": true
          }
        ]
      }
    ]
  ]
}

With this example:

• Slack notification will always be sent using the "https://my-webhook.com" webhook url
• Slack notifications are sent on a failure release from branches matching "lts/*"
• Slack notifications are sent on a failure or successful release from branch "master"
• Slack notifications are skipped on all other branches

Note

The official documentation says that a developer cannot override the default name, channel or icon that are associated with the webhook, but some users of this library reported that they were able to.

• use slackName (or SLACK_NAME env var) for overriding slack app name
• use slackIcon (or SLACK_ICON env var) for overriding slack app icon
• use slackChannel (or SLACK_CHANNEL env var) for overriding slack channel

WARNING: This is not mentioned in the official documentation, so use at your own risk.

Slack Access Token/Channel Usage

This configuration can be used with a bot Slack Access token with minimum permissions of chat:write.

The plugin can be configured in the semantic-release configuration file:

{
  "plugins": [
    "@semantic-release/commit-analyzer",
    "@semantic-release/release-notes-generator",
    [
      "semantic-release-slack-bot",
      {
        "notifyOnSuccess": false,
        "notifyOnFail": false,
        "slackToken": "token",
        "slackChannel": "#my-channel-name",
        "branchesConfig": [
          {
            "pattern": "lts/*",
            "notifyOnFail": true
          },
          {
            "pattern": "master1",
            "notifyOnSuccess": true,
            "notifyOnFail": true
          }
        ]
      }
    ]
  ]
}

With this example:

• Slack notification will always be sent to the channel "#my-channel-name"
• Slack notifications are sent on a failure release from branches matching "lts/*"
• Slack notifications are sent on a failure or successful release from branch "master"
• Slack notifications are skipped on all other branches

Screenshots

Configuration

Slack app installation

The plugin uses a slack webhook which you get by adding the slack app to your slack workspace. Register the app using the button below or this link.

For the security concerned, feel free to create your own slack app and create a webhook or inspect the server code that does this creation for you at create-webhook.js. The only required permission for the webhook is to publish to a single channel.

Slack Webhook

Installing the app will yield you with a webhook that the app uses to publish updates to your selected channel. The Slack webhook authentication link is required and needs to be kept a secret. It should be defined in the environment variables.

Slack Access tokens

If you are creating your own slack app you can choose to use a bot access token and channel instead of the webhook with at least one of the following permission scopes.

1. chat:write with this permission scope the app/bot must be added to any channels before it can post to them
2. chat:write.public with this permission scope we can automatically post to any public channel for more information see here

Environment variables

Options can be defined in the environment where you will run semantic release. This can be done by exporting it in bash or in the user interface of your CI provider.

Alternatively, you can pass the webhook as a configuration option or use an Access Token.

Variable	Description
SLACK_WEBHOOK	Slack webhook created when adding app to workspace.
SLACK_TOKEN	Slack bot Access token.
SLACK_CHANNEL	Slack channel name or id to send notifications to.
SLACK_ICON	Slack bot app icon.
SLACK_NAME	Slack bot app name.
SEMANTIC_RELEASE_PACKAGE	Override or add package name instead of npm package name

Options

Option	Description	Default
notifyOnSuccess	Determines if a successful release should trigger a slack message to be sent. If false this plugin does nothing on success.	false
notifyOnFail	Determines if a failed release should trigger a slack message to be sent. If false this plugin does nothing on fail.	false
onSuccessFunction	Provides a function for the slack message object on success when notifyOnSuccess is true. See function.	undefined
onFailFunction	Provides a function for the slack message object on fail when notifyOnFail is true. See function.	undefined
onSuccessTemplate	Provides a template for the slack message object on success when notifyOnSuccess is true. See templating.	undefined
onFailTemplate	Provides a template for the slack message object on fail when notifyOnFail is true. See templating.	undefined
markdownReleaseNotes	Pass release notes through markdown to slack formatter before rendering.	false
slackWebhookEnVar	This decides what the environment variable for exporting the slack webhook value.	SLACK_WEBHOOK
slackWebhook	Slack webhook created when adding app to workspace.	value of the environment variable matching slackWebhookEnVar
slackTokenEnVar	This decides what the environment variable for exporting the slack token value.	SLACK_TOKEN
slackToken	Slack bot token.	value of the environment variable matching slackTokenEnVar
slackChannelEnVar	This decides what the environment variable for exporting the slack channel value.	SLACK_CHANNEL
slackChannel	Slack channel name or id to send notifications to.	value of the environment variable matching slackChannelEnVar
slackIconEnVar	This decides what the environment variable for specifying the slack app icon with slack emoji. ex. :smile: or smile (without semicolons)	SLACK_ICON
slackIcon	Slack app icon	value of the environment variable matching slackIconEnVar
slackNameEnVar	This decides what the environment variable for specifying the slack app name	SLACK_NAME
slackName	Slack app name	value of the environment variable matching slackNameEnVar
packageName	Override or add package name instead of npm package name	SEMANTIC_RELEASE_PACKAGE or npm package name
unsafeMaxLength	Maximum character length for the release notes before truncation. If unsafeMaxLength is too high, messages can be dropped. Read here for more information. Set to '0' to turn off truncation entirely.	2900
branchesConfig	Allow to specify a custom configuration for branches which match a given pattern. For every branches matching a branch config, the config will be merged with the one put at the root. A key "pattern" used to filter the branch using glob expression must be contained in every branchesConfig.	[]

Function

If a function is provided with either the onSuccessFunction or onFailFunction options, it will be used for the respective slack message. The function should return an object that follows the Slack API message structure. The function is passed two objects, pluginConfig and context, the same objects that are passed to plugins.

Note: This only works with a configuration file that exports an object (see below for an example).

Example config (some parts omitted)

const slackifyMarkdown = require('slackify-markdown')
const { chunkifyString } = require('semantic-release-slack-bot/lib/chunkifier')

const onSuccessFunction = (pluginConfig, context) => {
  const releaseNotes = slackifyMarkdown(context.nextRelease.notes)
  const text = `Updates to ${pluginConfig.packageName} has been released to *Stage!*`
  const headerBlock = {
    type: 'section',
    text: {
      type: 'mrkdwn',
      text
    }
  }

  return {
    text,
    blocks: [
      headerBlock,
      ...chunkifyString(releaseNotes, 2900).map(chunk => {
        return {
          type: 'section',
          text: {
            type: 'mrkdwn',
            text: chunk
          }
        }
      })
    ]
  }
}

module.exports = {
  branches: ['master'],
  preset: 'eslint',
  plugins: [
    [
      'semantic-release-slack-bot',
      {
        notifyOnSuccess: true,
        onSuccessFunction,
        packageName: 'Testing Semantic Release'
      }
    ]
  ]
}

Templating

If a template is provided via either the onSuccessTemplate or onFailTemplate options, it will be used for the respective slack message. The template should be an object that follows the Slack API message structure. Strings within the template will have keywords replaced:

Keyword	Description	Example	Template
$package_name	The name of the package.	semantic-release-test	Both
$npm_package_version	The version of the release.	1.0.93	onSuccessTemplate
$repo_path	The repository path.	juliuscc/semantic-release-test	Both
$repo_url	The repository URL.	https://github.com/juliuscc/semantic-release-test	Both
$release_notes	The notes of the release.		onSuccessTemplate

A sample configuration with template can look like this

"onSuccessTemplate": {
  "text": "A new version of $package_name with version $npm_package_version has been released at $repo_url!"
}

Helper functions

There are two helper functions exported by the chunkifier module.

chunkifyArray takes an array of strings and returns a new array based on maxLength and delimiter. delimiter is optional and defaults to newline.

chunkifyString takes a string and returns an array based on maxLength and delimiter. delimiter is optional and defaults to newline.

See respective implementation for more details.