如何在 GitHub 操作中使用 bash 表达式设置环境变量？

Question

在 GitHub 操作中，我想计算一个 bash 表达式，然后将其分配给一个环境变量：

    - name: Tag image
      env:
        GITHUB_SHA_SHORT: ${{ $(echo $GITHUB_SHA | cut -c 1-6) }}
      ..do other things...

然而，这种幼稚的尝试失败了。 According to the docs 这似乎不受支持；稍微干净的解决方法就可以了。

Answer 1

这个问题的原始答案使用了 Actions runner 函数 set-env。由于 security vulnerability set-env 已弃用，不应再使用。

这是设置环境变量的新方法。

name: my workflow
on: push
jobs:
  build:
    runs-on: ubuntu-latest
    steps:
    - uses: actions/checkout@v2
    - name: Set env
      run: echo "GITHUB_SHA_SHORT=$(echo $GITHUB_SHA | cut -c 1-6)" >> $GITHUB_ENV
    - name: Test
      run: echo $GITHUB_SHA_SHORT

Setting an environment variable echo "{name}={value}" >> $GITHUB_ENV

Creates or updates an environment variable for any actions running next in a job. The action that creates or updates the environment variable does not have access to the new value, but all subsequent actions in a job will have access. Environment variables are case-sensitive and you can include punctuation.

（来自 https://help.github.com/en/actions/reference/workflow-commands-for-github-actions#setting-an-environment-variable）

使用输出到 $GITHUB_ENV 方法的示例：

    echo "GITHUB_SHA_SHORT=$(echo $GITHUB_SHA | cut -c 1-6)" >> $GITHUB_ENV

这是在工作流中引用环境变量的另一种方法。

    - name: Test
      run: echo ${{ env.GITHUB_SHA_SHORT }}

Answer 2

文档 https://docs.github.com/en/free-pro-team@latest/actions/reference/environment-variables#about-environment-variables 描述了 2 种定义环境变量的方法。

To set custom environment variables, you need to specify the variables in the workflow file. You can define environment variables for a step, job, or entire workflow using the jobs.<job_id>.steps[*].env, jobs.<job_id>.env, and env keywords.

steps:
  - name: Hello world
    run: echo Hello world $FIRST_NAME $middle_name $Last_Name!
    env:
      FIRST_NAME: Mona
      middle_name: The
      Last_Name: Octocat

You can also use the GITHUB_ENV environment file to set an environment variable that the following steps in a workflow can use. The environment file can be used directly by an action or as a shell command in a workflow file using the run keyword.

如何在 GitHub 操作中使用 bash 表达式设置环境变量？

How do I set an env var with a bash expression in GitHub Actions?

github-actions