Advanced configuration topics

Using YAML anchors

Configuration files for setups (setups.yaml) and service metadata (services/services.yaml) often contain repeated information (e.g. two setups might offer the same capabilities). You can use YAML anchors to simplify your configuration files.

The following example shows two services sharing a parameter seconds. The parameter is defined once for the sleep service and then reused in the docker_sleep service through the YAML anchor sleep_seconds.

- id: sleep
  name: sleep
  description: sleeps for the given amount of seconds
  path: sleep
  runtime: other
 
  parameters:
    - &sleep_seconds
      id: seconds
      name: seconds to sleep
      description: The number of seconds to sleep
      type: input
      cardinality: 1..1
      dataType: integer
 
- id: docker_sleep
  name: Docker sleep
  description: Run sleep inside an alpine container
  path: alpine
  runtime: docker
 
  parameters:
    - id: sleep
      name: sleep command
      description: The sleep command
      type: input
      cardinality: 1..1
      dataType: string
      default: sleep
 
    - *sleep_seconds
Provisioning scripts
Using a template engine