matrix-example.yml

# Matrix Job Example for Modal GitHub Runner
#
# This workflow demonstrates how to run matrix jobs on Modal runners.
#
# IMPORTANT: Each matrix job needs a unique label to get its own runner.
# Without unique labels, multiple matrix jobs compete for the same runner
# and get stuck in "queued" state.
#
# The pattern: job-${{ github.run_id }}-${{ strategy.job-index }}
#   - github.run_id  = unique per workflow run
#   - strategy.job-index = unique per matrix entry (0, 1, 2, ...)
#   Combined, they guarantee 1:1 binding between job and runner.

name: Matrix Example

on:
  workflow_dispatch:
  workflow_call:

jobs:
  test:
    runs-on:
      - self-hosted
      - modal
      - job-${{ github.run_id }}-${{ strategy.job-index }}
    timeout-minutes: 15

    strategy:
      matrix:
        python-version: ["3.10", "3.11", "3.12"]

    steps:
      - uses: actions/checkout@v4

      - name: Set up Python ${{ matrix.python-version }}
        run: |
          python${{ matrix.python-version }} --version || true
          echo "Testing with Python ${{ matrix.python-version }}"

      - name: Run tests
        run: |
          echo "Running tests on Python ${{ matrix.python-version }}"
          echo "Runner OS: $(uname -s)"
          echo "Runner arch: $(uname -m)"