jwinton/slack-github-action repository overview

⁠Simple Slack GitHub Action

This Action enables sending Slack messages to incoming webhook endpoints.

It works by taking in escaped JSON that is formatted for Slack's message API⁠ and send a request to the endpoint specified by environment variables⁠.

⁠Basic Usage

action "Notify" {
  needs = ["Filter For Tags"]
  uses = "jwinton/slack-github-action"
  args = ["{\"text\":\"The tag [BRANCH_OR_TAG] was just pushed!\"}"]
  env = {
    SLACK_PATH = "/T00000000/B00000000/XXXXXXXXXXXXXXXXXXXXXXXX"
  }
}

For some basic JSON examples see the examples page⁠.

⁠Prerequisites

• Create a Slack app⁠
• Enable Incoming Webhooks⁠

⁠Environment Variables & Interpolation

Only one environment variable is required:

• SLACK_PATH: should be set to the path of your Slack Incoming Webhook.
  • If your webhook url is https://hooks.slack.com/services/T00000000/B00000000/XXXXXXXXXXXXXXXXXXXXXXXX then the path will be /services/T00000000/B00000000/XXXXXXXXXXXXXXXXXXXXXXXX. Be sure to include the slash at the beginning

⁠Message Variable Interpolation

When constructing your message your can use environment variables in your message by wrapping a value in brackets. If an environement variable called FOO is set, your message can include [FOO] and it will be interpolated into the message. For example:

{
  "text": "This message is so show that environment variable FOO is set to: [FOO]"
}

This is handy for pulling in default environment variables provided by GitHub as well as passing in your own!

⁠Additional Environment Variables

As a way to make things easier a convenience environment variable called BRANCH_OR_TAG is added to the container. It is simply the name of the branch or value of a tag as defined by the default $GITHUB_REF environment variable. Combined with filters⁠ it can be a nice for certain messages.

⁠Usage

A simple notification for a push of a tag to a repo follows:

workflow "Test!" {
  on = "push"
  resolves = ["Send Message"]
}

# Filter for master branch
action "Filter For Tags" {
  uses = "actions/bin/filter@master"
  args = "tag v*"
}

action "Send Message" {
  needs = ["Filter For Tags"]
  uses = "docker://jwinton/slack-github-action"
  args = ["{\"text\":\"The tag [BRANCH_OR_TAG] was just pushed!\"}"]
  env = {
    SLACK_PATH = "/T00000000/B00000000/XXXXXXXXXXXXXXXXXXXXXXXX"
  }
}

⁠License

The Dockerfile and associated scripts and documentation in this project are released under the MIT License.