action.yml

name: Build Changeset Comment
author: Chandler Newby
description: Github Action that creates a GFMD comment with Cloudformation changeset details.

branding:
  icon: cloud
  color: orange

inputs:
  changes_json_file:
    description: Pass the path to the changeset file
    required: false
  changeset_arn:
    description: Pass the ARN of the changeset you want to describe.
    required: false

outputs:
  comment:
    description: The markdown formatted description of the changeset
    value: ${{ steps.build-comment.outputs.comment }}
  comment_json:
    description: The markdown formatted description of the changeset, in an escaped json string
    value: ${{ steps.build-comment.outputs.comment_json }}

runs:
  using: 'composite'
  steps:
    - name: Check inputs
      shell: bash
      run: |
        changes_json_file="${{ inputs.changes_json_file }}"
        changeset_arn="${{ inputs.changeset_arn }}"

        if [[ -n "$changes_json_file" && -n "$changeset_arn" ]]; then
            echo "Please only specify changes_json_file OR changeset_arn, not both."
            exit 1
        elif [[ -z "$changes_json_file" && -z "$changeset_arn" ]]; then
            echo "Please specify either changes_json_file or changeset_arn."
            exit 1
        fi

    - name: Install Python
      uses: actions/setup-python@v5
      with:
        python-version: '3.12'

    - name: Get the changeset details
      id: get-changeset-details
      if: inputs.changeset_arn != ''
      shell: bash
      run: |
        echo 'raw_changes<<EOF' >> $GITHUB_OUTPUT
        aws cloudformation describe-change-set --region $(echo $ARN | cut -d ':' -f 4) --change-set-name $ARN >> $GITHUB_OUTPUT
        echo 'EOF' >> $GITHUB_OUTPUT
      env:
        ARN: ${{ inputs.changeset_arn }}

    - name: Build the comment
      id: build-comment
      run: python "$GITHUB_ACTION_PATH/src/build-markdown.py"
      shell: bash
      env:
        CHANGES_JSON_FILE: ${{ inputs.changes_json_file }}
        RAW_CHANGES: ${{ steps.get-changeset-details.outputs.raw_changes }}