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Passing Parameters Between Tasks

This example shows how to pass parameters between tasks.

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from hera.workflows import DAG, Container, Parameter, Task, Workflow

with Workflow(generate_name="param-passing-", entrypoint="d") as w:
    out = Container(
        name="out",
        image="argoproj/argosay:v2",
        command=["cowsay"],
        outputs=Parameter(name="x", value=42),
    )
    in_ = Container(
        name="in",
        image="argoproj/argosay:v2",
        command=["cowsay"],
        args=["{{inputs.parameters.a}}"],
        inputs=Parameter(name="a"),
    )
    with DAG(name="d"):
        t1 = Task(name="a", template=out)
        t2 = Task(name="b", template=in_, arguments={"a": t1.get_parameter("x")})
        t1 >> t2

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apiVersion: argoproj.io/v1alpha1
kind: Workflow
metadata:
  generateName: param-passing-
spec:
  entrypoint: d
  templates:
  - name: out
    container:
      image: argoproj/argosay:v2
      command:
      - cowsay
    outputs:
      parameters:
      - name: x
        value: '42'
  - name: in
    container:
      image: argoproj/argosay:v2
      args:
      - '{{inputs.parameters.a}}'
      command:
      - cowsay
    inputs:
      parameters:
      - name: a
  - name: d
    dag:
      tasks:
      - name: a
        template: out
      - name: b
        depends: a
        template: in
        arguments:
          parameters:
          - name: a
            value: '{{tasks.a.outputs.parameters.x}}'

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