concourse pipelines to dot graphs

Usage

fly -t ci get-pipeline -p concourse | \
  pipeline2dot | \
  dot -Tpng > graph.png

Result

why?

At the moment, the Concourse web ui can't deal with some cases of cyclic dependencies.

(see concourse/concourse#4445)

E.g., consider the following pipeline:

jobs:
  - name: jobA0
    plan:
      - get: res-1

  - name: jobA
    plan:
      - get: res-1
        passed: [jobC]

  - name: jobB
    plan:
      - get: res-1
        passed: [jobA]

  - name: jobC
    plan:
      - get: res-1
        passed: [jobB]
      - get: res-2

resources:
  - name: res-1
    type: time
    source: {interval: 2m}

  - name: res-2
    type: time
    source: {interval: 2m}

Such pipeline has the following layout:

which brakes the UI (for now).

This tool can help you figure out where you introduced that cycle that is crashing your UI.

caveats

It currently doesn't support the non step-based in_parallel format (anything coming directly from fly -t $target get-pipeline) will work though (as it converts to step-based).

e.g., the following won't work

jobs:
- name: aa
  plan:
    - in_parallel:
      - get: bla

but this, will:

jobs:
- name: aa
  plan:
    - in_parallel:
        steps:
        - get: bla