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Inner Dag

This example shows how to use a DAG within another DAG.

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from hera.workflows import DAG, Parameter, Workflow, script


@script()
def hello(name: str):
    print("Hello, {name}!".format(name=name))


with Workflow(
    generate_name="callable-inner-dag-",
    entrypoint="calling-dag",
) as w:
    with DAG(name="my-dag", inputs=Parameter(name="my-dag-input")) as my_dag:
        hello(name="hello-1", arguments={"name": "hello-1-{{inputs.parameters.my-dag-input}}"})
        hello(name="hello-2", arguments={"name": "hello-2-{{inputs.parameters.my-dag-input}}"})

    with DAG(name="calling-dag") as d:
        t1 = my_dag(name="call-1", arguments={"my-dag-input": "call-1"})
        t2 = my_dag(name="call-2", arguments={"my-dag-input": "call-2"})
        t1 >> t2

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apiVersion: argoproj.io/v1alpha1
kind: Workflow
metadata:
  generateName: callable-inner-dag-
spec:
  entrypoint: calling-dag
  templates:
  - name: my-dag
    dag:
      tasks:
      - name: hello-1
        template: hello
        arguments:
          parameters:
          - name: name
            value: hello-1-{{inputs.parameters.my-dag-input}}
      - name: hello-2
        template: hello
        arguments:
          parameters:
          - name: name
            value: hello-2-{{inputs.parameters.my-dag-input}}
    inputs:
      parameters:
      - name: my-dag-input
  - name: hello
    inputs:
      parameters:
      - name: name
    script:
      image: python:3.10
      source: |-
        import os
        import sys
        sys.path.append(os.getcwd())
        import json
        try: name = json.loads(r'''{{inputs.parameters.name}}''')
        except: name = r'''{{inputs.parameters.name}}'''

        print('Hello, {name}!'.format(name=name))
      command:
      - python
  - name: calling-dag
    dag:
      tasks:
      - name: call-1
        template: my-dag
        arguments:
          parameters:
          - name: my-dag-input
            value: call-1
      - name: call-2
        depends: call-1
        template: my-dag
        arguments:
          parameters:
          - name: my-dag-input
            value: call-2

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