benchmark.yml

# This workflow runs a Criterion benchmark on a PR and compares the results against the base branch.
# It is triggered on a PR or a push to main.
#
# The workflow is gated on the presence of the "performance" label on the PR.
#
# The workflow runs on a self-hosted runner pool. We can't use the shared runners for this,
# because they are only permitted to run on the default branch to preserve resources. 
#
# In the future, we might like to consider using bencher.dev or the framework used by otel-golang here. 
on: 
  pull_request:
  push:
    branches:
      - main
name: benchmark pull requests
jobs:
  runBenchmark:
    name: run benchmark
    permissions:
      pull-requests: write

    # If we're running on a PR, use ubuntu-latest - a shared runner. We can't use the self-hosted
    # runners on arbitrary PRs, and we don't want to unleash that load on the pool anyway.     
    # If we're running on main, use the OTEL self-hosted runner pool. 
    runs-on: ${{ github.event_name == 'pull_request' && 'ubuntu-latest' || 'self-hosted' }}
    if: ${{ (github.event_name == 'pull_request' && contains(github.event.pull_request.labels.*.name, 'performance')) || github.event_name == 'push' }}
    env:
      # For PRs, compare against the base branch - e.g., 'main'. 
      # For pushes to main, compare against the previous commit
      BRANCH_NAME: ${{ github.event_name == 'pull_request' && github.base_ref || github.event.before }}
    steps:
      - uses: actions/checkout@v4
        with:
          fetch-depth: 10  # Fetch current commit and its parent
      - uses: arduino/setup-protoc@v3
        with:
          repo-token: ${{ secrets.GITHUB_TOKEN }}
      - uses: dtolnay/rust-toolchain@master
        with:
          toolchain: stable
      - uses: boa-dev/criterion-compare-action@v3
        with:
          cwd: opentelemetry
          branchName: ${{ env.BRANCH_NAME }}
      - uses: boa-dev/criterion-compare-action@v3
        with:
          cwd: opentelemetry-appender-tracing
          features: spec_unstable_logs_enabled
          branchName: ${{ env.BRANCH_NAME }}
      - uses: boa-dev/criterion-compare-action@v3
        with:
          cwd: opentelemetry-sdk
          features: rt-tokio,testing,metrics,logs,spec_unstable_metrics_views
          branchName: ${{ env.BRANCH_NAME }}