parallelism-nested-dag.yaml

# Example on specifying parallelism on the outer DAG and limiting the number of its
# children DAGs to be run at the same time.
# 
# As the parallelism of A is 2, only two of the three DAGs (b2, b3, b4) will start 
# running after b1 is finished, and the left DAG will run after either one is finished.

apiVersion: argoproj.io/v1alpha1
kind: Workflow
metadata:
  generateName: parallelism-nested-dag-
spec:
  entrypoint: A
  templates:
  - name: A
    parallelism: 2
    dag:
      tasks:
      - name: b1
        template: B
        arguments:
          parameters:
          - name: msg
            value: "1"
      - name: b2
        template: B
        dependencies: [b1]
        arguments:
          parameters:
          - name: msg
            value: "2"
      - name: b3
        template: B
        dependencies: [b1]
        arguments:
          parameters:
          - name: msg
            value: "3"
      - name: b4
        template: B
        dependencies: [b1]
        arguments:
          parameters:
          - name: msg
            value: "4"
      - name: b5
        template: B
        dependencies: [b2, b3, b4]
        arguments:
          parameters:
          - name: msg
            value: "5"

  - name: B
    inputs:
      parameters:
      - name: msg
    dag:
      tasks:
      - name: c1
        template: one-job
        arguments:
          parameters:
          - name: msg
            value: "{{inputs.parameters.msg}} c1"
      - name: c2
        template: one-job
        dependencies: [c1]
        arguments:
          parameters:
          - name: msg
            value: "{{inputs.parameters.msg}} c2"
      - name: c3
        template: one-job
        dependencies: [c1]
        arguments:
          parameters:
          - name: msg
            value: "{{inputs.parameters.msg}} c3"

  - name: one-job
    inputs:
      parameters:
      - name: msg
    container:
      image: alpine
      command: ['/bin/sh', '-c']
      args: ["echo {{inputs.parameters.msg}}; sleep 10"]