PlatformIO on GitHub Actions with cache accelerate

#githubactions #iot

Sample on official doc available

Official documentation suggests example workflow of using PlatformIO on GitHub Actions.

docs.platformio.org

name: PlatformIO CI

on: [push]

jobs:
  build:
    runs-on: ubuntu-latest

    steps:
      - uses: actions/checkout@v4
      - uses: actions/cache@v4
        with:
          path: |
            ~/.cache/pip
            ~/.platformio/.cache
          key: ${{ runner.os }}-pio
      - uses: actions/setup-python@v5
        with:
          python-version: '3.11'
      - name: Install PlatformIO Core
        run: pip install --upgrade platformio

      - name: Build PlatformIO Project
        run: pio run

Setup PlatformIO CLI pio, then run build by pio run. PlatformIO CLI is made with Python. So, it setups Python at first.

Additionally, Python and PlatformIO caching is there. Sometimes downloading speed will be unstable, and PlatformIO package size is a little heavy. So, caching them makes short workflow duration.

Improve more

That workflow has unpacking step, and it takes some time. So, caching unpacked filed, you can cut step of unpacking.

.platformio/ on home directory including download cache files and unpacked packages.

      - uses: actions/cache@v4
        with:
          path: |
            ~/.cache/pip
-           ~/.platformio/.cache
+           ~/.platformio/
          key: ${{ runner.os }}-pio

Note: But the packages will not be updated until same cache using.

Experiment

Let's check difference of duration of 3 pattern workflows: 'No cache', 'Download cached' and 'Unpack cached'

Target steps to measure: Cache restoring, PlatformIO installing and building
Take average of 5 times attempt
Ignore first attempt due to cache won't be hit
Target task: build (not unit-test)
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