gh-action-mattermost

⛔️DEPRECATED⛔️ This repository is now in archive mode as Mitigram has stopped using Mattermost. You may get some voluntary support through this friendly fork.

This implements a curl/sh-based action to send Mattermost notifications. The action provides for access to most of the parameters supported by incoming webhooks and provides automatic GitHub, workflow and runner information through the card mechanism. This information will be accessible from the info icon displayed alongside the post.

Usage

This action is designed to have good defaults. It will fail when some of required fields are not provided or when notification failed. Most inputs have the same name as the official parameters. For a complete list of all inputs, see action.yml.

In its default behaviour, this action will:

• Fail until you have at least provided a url and text field.
• Arrange for the icon of the sender to be the GitHub icon.
• Arrange for the name of the sender to be GitHub Action.
• Send the message to the default channel that is associated to the hook.
• Add an information card with context information to identify what caused the message more easily. No sensitive information is passed through the card.

Send a Test Message

The following workflow step would send a test message to the default channel.

-
  uses: Mitigram/gh-action-mattermost@main
  with:
    url: http://{your-mattermost-site}/hooks/xxx-generatedkey-xxx
    text: This is a test message

Send Multi-Line Markdown

Mattermost supports Markdown for the formatting of messages. In Markdown, line breaks have some semantic (next paragraph, bullet-list items, etc.). However, in the text passed to the Mattermost API through this action, line breaks should appear as the character sequence \n. In order to write multi-line messages, you will have to avoid YAML block scalars that preserve the line breaks, i.e. use >- at the beginning of your blocks and manually write the \n whenever necessary, as in the following example:

-
  uses: Mitigram/gh-action-mattermost@main
  with:
    url: http://{your-mattermost-site}/hooks/xxx-generatedkey-xxx
    text: >-
      This is a multi-line message, introducing a bullet point list, meaning
      that a blank line prior the start of the bullet list is preferred.\n\n
      + One item\n
      + Another item\n

Increased Verbosity

The options action input can be used to provide more options to the internal wrapper implementation. You can use -v to increase verbosity.

steps:
  uses: Mitigram/gh-action-mattermost@main
  with:
    url: http://{your-mattermost-site}/hooks/xxx-generatedkey-xxx
    text: This is a test message
    options: -v

Developer Notes

You can use the testing workflow.yml in combination with act to manually test this action. Provided act is installed, the following command, run from the root directory, would exercise this action:

act -b -W . -j test

Running act through dew is possible if you do not want to install act in your environment. Just replace act with dew act in the command above.