modification.yml

name: modification
on:
  workflow_dispatch:
  push:
    paths: .github/workflows/modification.yml

jobs:
  main:
    runs-on: ubuntu-latest
    steps:
    - name: Run the workflow script
      run: |
        # Make Bash print the commands as it is executing them
        set -x

        # Generate new file content by using the current date and time instant
        DATE=$(date -Iseconds)

        # Build the GitHub API URL using the GitHub Actions `github` context
        # https://docs.github.com/en/rest/reference/repos#create-or-update-file-contents
        # https://docs.github.com/en/actions/learn-github-actions/contexts#github-context
        URL="${{github.api_url}}/repos/${{github.repository}}/contents/artifact"

        # Call the GitHub API to fetch the current version's SHA as a base
        # Note that `-r` (raw) is used with `jq` to not get string quotes
        SHA=$(curl --no-progress-meter -u :${{github.token}} $URL | jq -r .sha)

        # Build the JSON payload string to send to the GitHub API endpoint
        # https://docs.github.com/en/rest/reference/repos#create-or-update-file-contents
        MESSAGE="Update workflow artifact file\n\nThis file was modified using the GitHub Actions workflow."
        CONTENT=$(echo $DATE | base64 -w 0)
        DATA='{"message":"'$MESSAGE'","content":"'$CONTENT'","sha":"'$SHA'"}'

        # Call the GitHub API endpoint using Basic auth with PAT for password
        # https://docs.github.com/en/rest/overview/other-authentication-methods#via-oauth-and-personal-access-tokens
        curl --no-progress-meter -u :${{github.token}} -X PUT $URL -d "$DATA"