如何消除GitHub Actions环境变量中的换行符？

问题原因 #

你用YAML的>折叠语法定义INFRA_ACCOUNT时，块内的换行和缩进会被保留为空白字符，最终导致INFRA_ACCOUNT的值末尾带有换行符，拼接ARN时就出现了换行拆分的情况。

解决方法 #

方法1：将JSON内联写成一行，移除折叠语法 #

直接把fromJson里的JSON结构压缩成一行，避免YAML块引入额外换行：

jobs:
  deploy_infra:
    name: Deploy Infra    
    env:
      INFRA_ACCOUNT: ${{ fromJson('{"dev": "12345", "preprd": "678234", "prd": "91056"}')[github.event.inputs.stage] }}
    steps:
      - name: Creating ARN
        shell: bash
        run: |
         echo "ARN is arn:aws:iam::${{ env.INFRA_ACCOUNT }}:role/aws-github-role"

方法2：用trim函数去除空白字符 #

如果想保留JSON的多行格式，在表达式中添加trim函数，自动去除值的首尾空白（包括换行）：

jobs:
  deploy_infra:
    name: Deploy Infra    
    env:
      INFRA_ACCOUNT: ${{ trim(fromJson('{
              "dev": "12345",
              "preprd": "678234",
              "prd": "91056"
            }')[github.event.inputs.stage]) }}
    steps:
      - name: Creating ARN
        shell: bash
        run: |
         echo "ARN is arn:aws:iam::${{ env.INFRA_ACCOUNT }}:role/aws-github-role"

方法3：在Shell命令中去除换行 #

如果不想修改环境变量定义，也可以在run命令里用tr命令删除换行符：

jobs:
  deploy_infra:
    name: Deploy Infra    
    env:
      INFRA_ACCOUNT: >
        ${{ fromJson('{
              "dev": "12345",
              "preprd": "678234",
              "prd": "91056"
            }')[github.event.inputs.stage] }}
    steps:
      - name: Creating ARN
        shell: bash
        run: |
         echo "ARN is arn:aws:iam::${{ env.INFRA_ACCOUNT }}:role/aws-github-role" | tr -d '\n'

内容的提问来源于stack exchange，提问作者change198