Argo-workflows: Generate dynamic json list

- name: get-deps
    inputs:
      parameters:
      - name: changes
    script:
      image: ubuntu:latest
      command: [bash]
      #args: ["echo result was: {{inputs.parameters.message}}"]
      source: |
        which jq || (apt-get update -y && apt-get install -y jq)
        cd /src/api2
        grep -Po "(?<=Local\/)src.*" changes.txt  > local_changes.txt
        grep -Po "(?<=Global\/)src.*" changes.txt  > global_changes.txt
        find ./Local/ -name Dockerfile | xargs grep -f local_changes.txt  > local_dockerfiles.txt
        find ./Global/ -name Dockerfile | xargs grep -f global_changes.txt  > global_dockerfiles.txt
        grep -o '^.*Dockerfile' local_dockerfiles.txt  | sort | uniq > ulocal_dockerfiles.txt
        grep -o '^.*Dockerfile' global_dockerfiles.txt  | sort | uniq > uglobal_dockerfiles.txt
        #cat ulocal_dockerfiles.txt uglobal_dockerfiles.txt > u_dockerfiles.txt
        jq -Rsc '[ split("\n") [] |select(length >0) ]' u_dockerfiles.txt
      volumeMounts:
        - mountPath: /src
          name: src

  - name: filejson
    script:
      image: python:alpine3.6
      command: [python]
      source: |
        import json
        import sys
        my_file = open("/src/api2/u_dockerfiles.txt", "r")

        # reading the file
        data = my_file.read()

        # replacing end splitting the text
        # when newline ('\n') is seen.
        data_into_list = data.split("\n")
        result =[f for f in data_into_list if len(f) >0]
        json.dump(result, sys.stdout)
        my_file.close()
      volumeMounts:
        - mountPath: /src
          name: src

apiVersion: argoproj.io/v1alpha1
kind: Workflow
metadata:
  generateName: loops-param-arg-
spec:
  entrypoint: loop-param-arg-example
  serviceAccountName: argo
  templates:
  - name: loop-param-arg-example
    steps:
    - - name: jq
        template: jq-list
    - - name: test-linux
        template: cat-os-release
        arguments:
          parameters:
          - name: image
            value: "{{item}}"
        withParam: "{{steps.jq.outputs.parameters.json}}"

  - name: jq-list
    script:
      image: ubuntu:latest
      command: [bash]
      source: |
        which jq || (apt-get update -y && apt-get install jq -y)
        cat <<EOF | jq -Rsc '[ split("\n") [] |select(length >0) ]'  > /tmp/result.json
        debian
        alpine
        ubuntu
        EOF
    outputs:
      parameters:
         - name: json
           valueFrom:
             path: /tmp/result.json
  - name: cat-os-release
    inputs:
      parameters:
      - name: image
    script:
      image: ubuntu:latest
      command: [bash]
      source: |
        echo 'image: {{  inputs.parameters.image }}'