Determine GitHub Action Runner IP

I recently had the need to determine the IP address of the server running my GitHib Action. Knowing this may be useful to match-up individual workflow runs with specific entries in log files, or temporarily whitelisting the action runner’s IP during testing.

I found that a cURL request to ipify.org can achieve this simply:

on:
  workflow_dispatch:
  push:

jobs:
  ci:
    runs-on: ubuntu-latest
    steps:
      - name: 🛒 Checkout
        uses: actions/checkout@v2
      - name: 🔎 Check IP
        run: curl https://api.ipify.org

There are published/shared Actions which do something similar (e.g., haythem/public-ip) but whenever possible I avoid these because they are a potential vector for supply chain attacks (a compromised action could access secrets in environment variables).

Resources

• The GitHub meta endpoint shows all IP ranges used by GitHub Actions runners and may be useful for whitelisting purposes.