Skip to content

Dag Conditional Parameters

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
from hera.expr import g
from hera.workflows import DAG, Parameter, Workflow, script


@script(add_cwd_to_sys_path=False, image="python:alpine3.6")
def heads():
    print("heads")


@script(add_cwd_to_sys_path=False, image="python:alpine3.6")
def tails():
    print("tails")


@script(add_cwd_to_sys_path=False, image="python:alpine3.6")
def flip_coin():
    import random

    print("heads" if random.randint(0, 1) == 0 else "tails")


with Workflow(
    generate_name="dag-conditional-parameter-",
    entrypoint="main",
) as w:
    with DAG(name="main") as main_dag:
        fc = flip_coin(name="flip-coin")
        h = heads(name="heads").on_other_result(fc, "heads")
        t = tails(name="tails").on_other_result(fc, "tails")

        expression = g.tasks["flip-coin"].outputs.result == "heads"
        expression = expression.check(g.tasks.heads.outputs.result, g.tasks.tails.outputs.result)  # type: ignore
        main_dag.outputs = [Parameter(name="stepresult", value_from={"expression": str(expression)})]

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
apiVersion: argoproj.io/v1alpha1
kind: Workflow
metadata:
  generateName: dag-conditional-parameter-
spec:
  entrypoint: main
  templates:
  - dag:
      tasks:
      - name: flip-coin
        template: flip-coin
      - depends: flip-coin
        name: heads
        template: heads
        when: '{{tasks.flip-coin.outputs.result}} == heads'
      - depends: flip-coin
        name: tails
        template: tails
        when: '{{tasks.flip-coin.outputs.result}} == tails'
    name: main
    outputs:
      parameters:
      - name: stepresult
        valueFrom:
          expression: 'tasks[''flip-coin''].outputs.result == ''heads'' ? tasks.heads.outputs.result
            : tasks.tails.outputs.result'
  - name: flip-coin
    script:
      command:
      - python
      image: python:alpine3.6
      source: |-
        import random
        print('heads' if random.randint(0, 1) == 0 else 'tails')
  - name: heads
    script:
      command:
      - python
      image: python:alpine3.6
      source: print('heads')
  - name: tails
    script:
      command:
      - python
      image: python:alpine3.6
      source: print('tails')

Comments