Github Workflows: working with concurrency

When running SonarQube in GitHub Actions, you often want to avoid multiple scans running at the same time.

Imagine you have a Sonarqube set up in your repo and you want to configure your workflows so that only one Sonarqube scan is allowed at the same time. GitHub Actions concurrency lets you do this in different ways depending on whether you want to:

1. Replace older runs with newer ones, or
2. Queue runs and process them one at a time

The concurrency keyword

concurrency in GitHub Actions controls how many executions are allowed at the same time for a given concurrency group.

You can define it at two scopes:

Workflow (pipeline) level

When concurrency is defined at the top of the workflow file, it applies to the entire workflow run.

name: CI

on:
  push:

concurrency:
  group: ci-${{ github.repository }}-${{ github.ref }}
  cancel-in-progress: false
  queue: max

jobs:
  build:
    runs-on: ubuntu-latest
    steps:
      - run: echo "Build"

  sonarqube:
    runs-on: ubuntu-latest
    steps:
      - run: echo "Scan"

Effect: only one full workflow run in that group proceeds at a time.

Job level