---
apiVersion: argoproj.io/v1alpha1
kind: WorkflowTemplate
metadata:
  name: fetch-git
  namespace: cicd-system
spec:
  arguments:
    parameters:
    - name: repo
      value: ""
    - name: ref
      value: master
    - name: path
      value: "/usr/src"
  templates:
  - name: main
    inputs:
      parameters:
      - name: repo
        value: "{{workflow.parameters.repo}}"
      - name: ref
        value: "{{workflow.parameters.ref}}"
      - name: path
        value: "{{workflow.parameters.path}}"
    outputs:
      artifacts:
      - name: src
        path: "{{inputs.parameters.path}}"
    script:
      image: debian
      command:
      - dash
      source: |
        export DEBIAN_FRONTEND=noninteractive
        export GIT_WORK_TREE="{{inputs.parameters.path}}"
        export GIT_DIR="$(mktemp -d)"
        mkdir -pv -- "$GIT_WORK_TREE"

        apt update && apt install -y git

        git init
        git remote add origin "{{inputs.parameters.repo}}"
        git fetch origin -a
        git reset --hard "{{inputs.parameters.ref}}"
...