Passing Output Parameters Between Tasks

This document introduces the three-level output passing model of AtomGit Action: Step → Job → Workflow, which supports sharing data across steps and tasks.

When you need to pass output parameters between steps, jobs, or even workflows, for example, passing the build version number from the build job to the deploy job.

Prerequisites

• Understand the roles of id, outputs, and needs.
• Understand the usage of the ATOMGIT_OUTPUT environment variable.

Quick Example

name: pipeline-with-outputs

on:
  push:
    branches:
      - main

jobs:
  prepare:
    name: Prepare
    runs-on: [ubuntu-latest, x64, small]
    steps:
      - name: Run output version
      	id: version
        run: echo "version=1.0.0" >> "$ATOMGIT_OUTPUT"
      - name: Run output sha
      	id: sha
        run: echo "sha=${{ atomgit.sha }}" >> "$ATOMGIT_OUTPUT"

  build:
    name: Build
    runs-on: [ubuntu-latest, x64, small]
    needs: prepare
    steps:
      - name: Use output from prepare
        run: |
          echo "version=${{ jobs.prepare.outputs.version }}"
          echo "sha=${{ jobs.prepare.outputs.sha }}"

Configuration Instructions

Three-Level Transmission Model

AtomGit Action supports three-level output transmission: Step → Job → Workflow

Step Output (ATOMGIT_OUTPUT)
  → Mapped to Job Output (jobs.<job_id>.outputs)
    → Mapped to Workflow_call Job Output (jobs.workflow_call_job_id.outputs)

Step Output

Write outputs in a step using the ATOMGIT_OUTPUT environment variable:

steps:
  - name: Run output 
  	id: version
    run: echo "version=1.0.0" >> "$ATOMGIT_OUTPUT"

  - name: Run build 
  	id: build-result
    run: |
      echo "status=success" >> "$ATOMGIT_OUTPUT"
      echo "artifact-path=dist/app.tar.gz" >> "$ATOMGIT_OUTPUT"

  - name: Use step output
    run: echo "version=${{ steps.version.outputs.version }}"

Note: The value of each output parameter cannot exceed 1MB. Use delimiter syntax for multi-line outputs.

Job Output

Map step outputs to job outputs so that other jobs can reference them via needs:

jobs:
  prepare:
    name: Prepare
    runs-on: [ubuntu-latest, x64, small]
    steps:
      - name: Run output 
      	id: version
        run: echo "version=1.0.0" >> "$ATOMGIT_OUTPUT"
      - name: Run build
      	id: build-result
        run: echo "status=success" >> "$ATOMGIT_OUTPUT"

  deploy:
    runs-on: [ubuntu-latest, x64, small]
    needs: prepare
    steps:
      - name: Use job output
        run: |
          echo "version=${{ jobs.prepare.outputs.version }}"
          echo "status=${{ jobs.prepare.outputs.status }}"

Workflow Output

In a reusable workflow (workflow_call), you can map job outputs to workflow outputs:

name: reusable-build

on:
  workflow_call:
    outputs:
      version:
        description: "Build version number"
        value: ${{jobs.prepare.outputs.version}}

jobs:
  prepare:
    name: Prepare
    runs-on: [ubuntu-latest, x64, small]
    steps:
      - name: Run output 
      	id: version
        run: echo "version=1.0.0" >> "$ATOMGIT_OUTPUT"

Caller receives the output:

jobs:
  call-build:
    name: Call build
    uses: ./.gitcode/workflows/reusable-build.yml
  deploy:
    name: Deploy
    needs: call-build
    runs-on: [ubuntu-latest, x64, small]
    steps:
      - name: Use workflow output
        run: echo "version=${{ jobs.call-build.outputs.version }}"

Multi-Line Output

Use delimiter syntax when writing multi-line values to ATOMGIT_OUTPUT:

steps:
  - name: Run output 
  	id: multiline-output
    run: |
      EOF=$(dd if=/dev/urandom bs=15 count=1 status=none | base64)
      echo "content<<$EOF" >> "$ATOMGIT_OUTPUT"
      echo "line1" >> "$ATOMGIT_OUTPUT"
      echo "line2" >> "$ATOMGIT_OUTPUT"
      echo "$EOF" >> "$ATOMGIT_OUTPUT"