Passing Output Parameters Between Tasks

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

Prerequisites

• Understand the roles of id, outputs, and needs.
• Understand how to use the ATOMGIT_OUTPUT environment variable.

Quick Example

name: pipeline-with-outputs

on:
  push:
    branches:
      - main

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

  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 Description

Three-Level Transmission Model

AtomGit Action supports three-level transmission of outputs: 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:
  - id: version
    run: echo "version=1.0.0" >> "$ATOMGIT_OUTPUT"

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

Caller receives the output:

jobs:
  call-build:
    uses: ./.gitcode/workflows/reusable-build.yml
  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:
  - 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"