fibonacci-seq-conditional-param.yaml

apiVersion: argoproj.io/v1alpha1
kind: Workflow
metadata:
  generateName: fibonacci-
  annotations:
    workflows.argoproj.io/description: |
      This example demonstrates fibonacci sequence problem using conditional parameter feature.
    workflows.argoproj.io/veriiony: ">= 3.1.0"
spec:
  entrypoint: main
  arguments:
    parameters:
      - name: num
        value: "5"
  templates:
    - name: main
      steps:
        - - name: fibonaccimain
            template: fibonacci
            arguments:
              parameters:
                - name: num
                  value: "{{workflow.parameters.num}}"
        - - name: printresult
            template: printresult
            arguments:
              parameters:
                - name: result
                  value: "{{steps.fibonaccimain.outputs.parameters.fib}}"
    - name: fibonacci
      inputs:
        parameters:
          - name: num
      memoize:
        key: "{{inputs.parameters.num}}"
        maxAge: "120s"
        cache:
          configMap:
            name: fibonacci-m
            key: fibonacci-cache
      steps:
        - - name: fibonacci-helper
            template: fibonaccihelper
            when: "{{inputs.parameters.num}} != 1 && {{inputs.parameters.num}} != 2"
            arguments:
              parameters:
                - name: num-1
                  value: "{{inputs.parameters.num}}"
      outputs:
        parameters:
          - name: fib
            valueFrom:
              # If template name has "-" then variable path should have steps['fibonacci-helper']
              expression: "asInt(inputs.parameters.num) == 1? 1: asInt(inputs.parameters.num) == 2? 1: steps['fibonacci-helper'].outputs.parameters.result"
    - name: fibonaccihelper
      inputs:
        parameters:
          - name: num-1
      steps:
        - - name: sub-1
            template: do-math
            arguments:
              parameters:
                - { name: a, value: "{{inputs.parameters.num-1}}" }
                - { name: op, value: "-" }
                - { name: b, value: "1" }
        - - name: sub-2
            template: do-math
            when: "{{inputs.parameters.num-1}} != 1 && {{inputs.parameters.num-1}} != 2"
            arguments:
              parameters:
                - { name: a, value: "{{inputs.parameters.num-1}}" }
                - { name: op, value: "-" }
                - { name: b, value: "2" }
        - - name: fib-sub-1
            template: fibonacci
            arguments:
              parameters:
                - name: num
                  value: "{{steps.sub-1.outputs.result}}"
        - - name: fib-sub-2
            template: fibonacci
            arguments:
              parameters:
                - name: num
                  value: "{{steps.sub-2.outputs.result}}"
        - - name: add
            template: do-math
            arguments:
              parameters:
                - { name: a, value: "{{steps.fib-sub-1.outputs.parameters.fib}}" }
                - { name: op, value: "+" }
                - { name: b, value: "{{steps.fib-sub-2.outputs.parameters.fib}}" }
      outputs:
        parameters:
          - name: result
            valueFrom:
              parameter: "{{steps.add.outputs.result}}"
    - name: return-1
      script:
        image: python:alpine3.6
        command: [ python ]
        source: print(1)

    - name: do-math
      inputs:
        parameters:
          - name: a
          - name: op
          - name: b
      script:
        image: python:alpine3.6
        command: [ python ]
        source: |
          print({{inputs.parameters.a}} {{inputs.parameters.op}} {{inputs.parameters.b}})

    - name: printresult
      inputs:
        parameters:
          - name: result
      container:
        image: alpine:latest
        command: [ sh, -c ]
        args: [ "echo {{inputs.parameters.result}}" ]