cancel

The cancel step type stops and removes a background container service that an earlier step started with background: true. It gives you explicit, in-workflow teardown for long-running dependencies — emulators, databases, registries — without dropping into shell scripts to track and kill container IDs.

Name the background service to stop with the for field. Atmos gracefully stops the container and removes it:

steps:
  - name: emulator
    type: container
    action: run
    background: true
    with:
      image: localstack/localstack
      ports:
        - host: 4566
          container: 4566
      healthcheck:
        test: ["CMD", "curl", "-f", "http://localhost:4566/_localstack/health"]
        interval: 5s
        retries: 10
        start_period: 30s

  - name: apply
    type: atmos
    command: terraform apply vpc -s dev

  - type: cancel
    for: emulator

Fields

for

Name of the background service step to stop and remove. Must reference an earlier action: run step with background: true. The container is gracefully stopped, then removed.

Automatic teardown

A cancel step is optional. If you never cancel a background service explicitly, Atmos automatically tears down all background services when the workflow ends — including on failure — so a crashed or short-circuited workflow does not leave orphaned containers running. Use cancel when you want to free a service early, before the workflow finishes, or to make teardown explicit in the workflow file.

See background services on the container step page for the full lifecycle, and wait for gating steps on service readiness.