Concourse pipelines
This documents some of the agreed styles we have to writing Concourse pipelines. Because these are written in YAML, the YAML styleguide also applies.
Triggering patterns
Most of our pipelines follow the following pattern for triggering jobs. This should be used unless there’s a good reason not to.
Pipelines start with an init job that bumps a pipeline-trigger semver
resource. This resource is then used to trigger everything else througout the
pipeline. This ensures that all of a pipeline runs, even if some of the
jobs/tasks are a no-op. It also means there is a consistent way to initiate a
pipeline run (where they are triggered manually).
Tasks
Naming
Tasks should be given names that are verbs. Inputs and outputs should be given names that are nouns. Inputs and outputs should not be given names that are the same as a task name.
For example a task that takes a terraform state file and extracts the outputs
should be named as follows:
yaml
- task: extract-terraform-outputs
config:
# ...
inputs:
- name: paas-cf
- name: foo-tfstate
outputs:
- name: terraform-outputs
run:
# ...
Ordering of sections
Task config section should be ordered as follows:
platformimageorimage_resourceinputsoutputsparamsrun
This makes it easier to follow the flow of a task and see what it operates on.