Github Actions，如何在作业步骤之间共享计算值？

是否有一种 DRY 方法可以使用 Github Actions 在多个作业步骤中计算和共享值？

在下面的工作流程 yml 文件中，回声 ${GITHUB_REF} |剪切-d'/'-f3`-${GITHUB_SHA}在多个步骤中重复。

name: Test, Build and Deploy
on:
  push:
    branches:
      - master
jobs:
  build_and_push:
    name: Build and Push
    runs-on: ubuntu-latest
    steps:
      - name: Docker Build
        uses: "actions/docker/cli@master"
        with:
          args: build . --file Dockerfile -t cflynnus/blog:`echo ${GITHUB_REF} | cut -d'/' -f3`-${GITHUB_SHA}
      - name: Docker Tag Latest
        uses: "actions/docker/cli@master"
        with:
          args: tag cflynnus/blog:`echo ${GITHUB_REF} | cut -d'/' -f3`-${GITHUB_SHA} cflynnus/blog:latest

set-output https://help.github.com/en/actions/reference/workflow-commands-for-github-actions#setting-an-output-parameter可用于定义步骤的输出。然后可以在后续步骤中使用输出并在with and env输入部分。此外，返回输出的步骤应该有一个id，这是由消耗输出的步骤引用的。

以下是您的示例的外观。

name: Test, Build and Deploy
on:
  push:
    branches:
      - master
jobs:
  build_and_push:
    name: Build and Push
    runs-on: ubuntu-latest
    steps:
      - name: Set tag var
        id: vars
        run: echo "docker_tag=$(echo ${GITHUB_REF} | cut -d'/' -f3)-${GITHUB_SHA}" >> $GITHUB_OUTPUT
      - name: Docker Build
        uses: "actions/docker/cli@master"
        with:
          args: build . --file Dockerfile -t cflynnus/blog:${{ steps.vars.outputs.docker_tag }}
      - name: Docker Tag Latest
        uses: "actions/docker/cli@master"
        with:
          args: tag cflynnus/blog:${{ steps.vars.outputs.docker_tag }} cflynnus/blog:latest

这是另一个示例，显示如何动态设置操作要使用的多个变量。

      - name: Set output variables
        id: vars
        run: |
          pr_title="[Test] Add report file $(date +%d-%m-%Y)"
          pr_body="This PR was auto-generated on $(date +%d-%m-%Y) \
            by [create-pull-request](https://github.com/peter-evans/create-pull-request)."
          echo "pr_title=$pr_title" >> $GITHUB_OUTPUT
          echo "pr_body=$pr_body" >> $GITHUB_OUTPUT
      - name: Create Pull Request
        uses: peter-evans/create-pull-request@v4
        with:
          title: ${{ steps.vars.outputs.pr_title }}
          body: ${{ steps.vars.outputs.pr_body }}

或者，您可以创建环境变量。

      - name: Set environment variables
        run: |
          echo "PR_TITLE=[Test] Add report file $(date +%d-%m-%Y)" >> $GITHUB_ENV
          echo "PR_BODY=This PR was auto-generated on $(date +%d-%m-%Y) by [create-pull-request](https://github.com/peter-evans/create-pull-request)." >> $GITHUB_ENV
      - name: Create Pull Request
        uses: peter-evans/create-pull-request@v4
        with:
          title: ${{ env.PR_TITLE }}
          body: ${{ env.PR_BODY }}

Update:第一个示例中的 docker 操作已弃用。请参见这个答案 https://stackoverflow.com/questions/58350578/new-location-of-docker-actions/58350591#58350591了解在 GitHub Actions 中使用 docker 的最新方法。

Note:为了在人与人之间分享价值观不同的职位，请参阅这个问题 https://stackoverflow.com/questions/59175332/using-output-from-a-previous-job-in-a-new-one-in-a-github-action.