如何在Github Actions中按指定环境传递自定义环境变量

你当前的Workflow里，env字段用了嵌套对象来定义各环境变量，但GitHub Actions不支持这种嵌套结构，没法直接通过选择的环境名获取对应变量。下面是几种可行的实现方案：

原Workflow代码（已翻译为中文） #

name: Adios CD 流水线
on:
  workflow_dispatch:
    inputs:
      ENVIRONMENT:
        type: choice
        description: '选择要部署的环境'
        required: true
        options:
          - dev
          - qa
          - uat
          - load
          - prod
        default: 'dev'
env:
  Dev:
    AWS_REGION: "us-east-1"
    STAGE: "${{ github.event.inputs.ENVIRONMENT }}"
    SYSTEM: "ADIOSAPP"
  QA:
    AWS_REGION: "us-east-1"
    STAGE: "${{ github.event.inputs.ENVIRONMENT }}"
    SYSTEM: "ADIOSAPP"

jobs:
  build:
    name: "将 ${{ github.ref_name }} 分支部署到 ${{ github.event.inputs.ENVIRONMENT }} 环境"
    runs-on: ubuntu-latest
    environment: ${{ github.event.inputs.ENVIRONMENT }}
    steps:
      - name: 拉取代码
        uses: actions/checkout@v3
      - name: 配置AWS凭证
        uses: aws-actions/configure-aws-credentials@v1
        with:
          aws-region: ${{ env.AWS_REGION }}

方案一：JSON映射+fromJSON动态解析变量 #

把所有环境变量定义成JSON格式的映射，通过fromJSON函数根据选择的环境名动态提取对应变量，适合变量不多、需要集中管理的场景：

name: Adios CD 流水线
on:
  workflow_dispatch:
    inputs:
      ENVIRONMENT:
        type: choice
        description: '选择要部署的环境'
        required: true
        options:
          - dev
          - qa
          - uat
          - load
          - prod
        default: 'dev'
env:
  # 定义全环境变量映射，key与下拉选项的环境名保持一致（小写）
  ENV_VARS_MAP: |
    {
      "dev": {"AWS_REGION": "us-east-1", "SYSTEM": "ADIOSAPP"},
      "qa": {"AWS_REGION": "us-east-1", "SYSTEM": "ADIOSAPP"},
      "uat": {"AWS_REGION": "us-west-2", "SYSTEM": "ADIOSAPP"},
      "load": {"AWS_REGION": "eu-west-1", "SYSTEM": "ADIOSAPP"},
      "prod": {"AWS_REGION": "us-east-1", "SYSTEM": "ADIOSAPP_PROD"}
    }

jobs:
  build:
    name: "将 ${{ github.ref_name }} 分支部署到 ${{ github.event.inputs.ENVIRONMENT }} 环境"
    runs-on: ubuntu-latest
    environment: ${{ github.event.inputs.ENVIRONMENT }}
    # 解析当前环境的变量，作为Job级环境变量
    env:
      AWS_REGION: ${{ fromJSON(env.ENV_VARS_MAP)[github.event.inputs.ENVIRONMENT].AWS_REGION }}
      SYSTEM: ${{ fromJSON(env.ENV_VARS_MAP)[github.event.inputs.ENVIRONMENT].SYSTEM }}
      STAGE: ${{ github.event.inputs.ENVIRONMENT }}
    steps:
      - name: 拉取代码
        uses: actions/checkout@v3
      - name: 配置AWS凭证
        uses: aws-actions/configure-aws-credentials@v1
        with:
          aws-region: ${{ env.AWS_REGION }}
      - name: 验证变量
        run: |
          echo "当前环境: ${{ env.STAGE }}"
          echo "AWS区域: ${{ env.AWS_REGION }}"
          echo "系统标识: ${{ env.SYSTEM }}"

方案二：利用GitHub Environments内置变量（推荐） #

GitHub仓库的Environments功能支持为每个环境单独配置变量和机密，既安全（机密不会暴露在Workflow代码中），又方便后续维护：

1. 进入仓库Settings → Environments，分别创建dev、qa、uat、load、prod环境
2. 为每个环境添加对应的变量（如AWS_REGION、SYSTEM）和机密（如AWS密钥）
3. 修改Workflow代码直接引用环境级变量：

name: Adios CD 流水线
on:
  workflow_dispatch:
    inputs:
      ENVIRONMENT:
        type: choice
        description: '选择要部署的环境'
        required: true
        options:
          - dev
          - qa
          - uat
          - load
          - prod
        default: 'dev'

jobs:
  build:
    name: "将 ${{ github.ref_name }} 分支部署到 ${{ github.event.inputs.ENVIRONMENT }} 环境"
    runs-on: ubuntu-latest
    environment: ${{ github.event.inputs.ENVIRONMENT }}
    env:
      STAGE: ${{ github.event.inputs.ENVIRONMENT }}
    steps:
      - name: 拉取代码
        uses: actions/checkout@v3
      - name: 配置AWS凭证
        uses: aws-actions/configure-aws-credentials@v1
        with:
          aws-region: ${{ vars.AWS_REGION }} # 引用环境级公开变量
          aws-access-key-id: ${{ secrets.AWS_ACCESS_KEY_ID }} # 引用环境机密
          aws-secret-access-key: ${{ secrets.AWS_SECRET_ACCESS_KEY }}
      - name: 验证变量
        run: |
          echo "当前环境: ${{ env.STAGE }}"
          echo "AWS区域: ${{ vars.AWS_REGION }}"
          echo "系统标识: ${{ vars.SYSTEM }}"

方案三：步骤内通过Shell命令动态设置变量 #

适合变量逻辑简单、不需要集中管理的场景，通过case语句根据选择的环境写入变量：

name: Adios CD 流水线
on:
  workflow_dispatch:
    inputs:
      ENVIRONMENT:
        type: choice
        description: '选择要部署的环境'
        required: true
        options:
          - dev
          - qa
          - uat
          - load
          - prod
        default: 'dev'

jobs:
  build:
    name: "将 ${{ github.ref_name }} 分支部署到 ${{ github.event.inputs.ENVIRONMENT }} 环境"
    runs-on: ubuntu-latest
    environment: ${{ github.event.inputs.ENVIRONMENT }}
    steps:
      - name: 拉取代码
        uses: actions/checkout@v3
      - name: 动态设置环境变量
        run: |
          case "${{ github.event.inputs.ENVIRONMENT }}" in
            dev)
              echo "AWS_REGION=us-east-1" >> $GITHUB_ENV
              echo "SYSTEM=ADIOSAPP" >> $GITHUB_ENV
              ;;
            qa)
              echo "AWS_REGION=us-east-1" >> $GITHUB_ENV
              echo "SYSTEM=ADIOSAPP" >> $GITHUB_ENV
              ;;
            uat)
              echo "AWS_REGION=us-west-2" >> $GITHUB_ENV
              echo "SYSTEM=ADIOSAPP" >> $GITHUB_ENV
              ;;
            load)
              echo "AWS_REGION=eu-west-1" >> $GITHUB_ENV
              echo "SYSTEM=ADIOSAPP" >> $GITHUB_ENV
              ;;
            prod)
              echo "AWS_REGION=us-east-1" >> $GITHUB_ENV
              echo "SYSTEM=ADIOSAPP_PROD" >> $GITHUB_ENV
              ;;
          esac
          echo "STAGE=${{ github.event.inputs.ENVIRONMENT }}" >> $GITHUB_ENV
      - name: 配置AWS凭证
        uses: aws-actions/configure-aws-credentials@v1
        with:
          aws-region: ${{ env.AWS_REGION }}
      - name: 验证变量
        run: |
          echo "当前环境: ${{ env.STAGE }}"
          echo "AWS区域: ${{ env.AWS_REGION }}"
          echo "系统标识: ${{ env.SYSTEM }}"

内容的提问来源于stack exchange，提问作者Raghu Ram