Azure YAML中PowerShell输出变量无法跨阶段传递问题排查

问题现象 #

从与azure-pipelines.yml同目录的.version文件提取major和minor版本号时，GetVersion阶段可正常输出变量值，但后续阶段出现异常：

• BuildMasterVersion阶段构建号被更新为..8（major和minor变量为空）
• TagRelease阶段触发PowerShell错误：major : The term 'major' is not recognized as the name of a cmdlet...

错误信息 #

BuildMasterVersion阶段错误 #

The value is 
Async Command Start: Update Build Number
Update build number to ..8 for build 14074
Async Command End: Update Build Number
Finishing: PowerShell

TagRelease阶段错误 #

major : The term 'major' is not recognized as the name of a cmdlet, function, script file, or operable program. Check 
the spelling of the name, or if a path was included, verify that the path is correct and try again.
At C:\grmn\prj\mrn\vsts-agent\_work\_temp\97b95723-b57c-451c-9e65-17cbecac17cf.ps1:3 char:20
+ if ($(git tag -l $(major).$(minor).20)) {
+                    ~~~~~
    + CategoryInfo          : ObjectNotFound: (major:String) [], ParentContainsErrorRecordException
    + FullyQualifiedErrorId : CommandNotFoundException

##[error]PowerShell exited with code '1'.
Finishing: PowerShell

原azure-pipelines.yml配置 #

pool:
  name: Marine-Server

stages:

- stage: GetVersion
  displayName: Get Major and Minor Version from .Version File 
  jobs:
  - job: Get_Major_Minor_From_Version_File
    steps:
      - checkout: self
      - task: PowerShell@2
        inputs:
          targetType: 'inline'
          script: |
            $version = Get-Content -Path .version -TotalCount 1
            $versionSplit = $version.Split(".")
            $major = $versionSplit[0]
            $minor = $versionSplit[1]
            Write-Host ##vso[task.setvariable variable=major;isOutput=true]$major
            Write-Host "The value of major is $($major)"
            Write-Host ##vso[task.setvariable variable=minor;isOutput=true]$minor
            Write-Host "The value of minor is $($minor)"
          name: 'GetMajorMinorVersion' 

# # Versioning master branch  builds

- stage: BuildMasterVersion
  displayName: Build_Master_Version_Number 
  #change to 'refs/head/master' or master when done  testing
  condition: and(eq(variables['Build.SourceBranchName'], 'convert-to-commonjs-module-with-tags-implementation'), eq(variables['Build.Reason'], 'IndividualCI'))
  jobs:
  - job: Build_Master_Version_Number
    # variables:
       #patch: $[counter(variables['minor'], 0)]
    variables:
      major: $[stageDependencies.GetVersion.Get_Major_Minor_From_Version_File.outputs['GetMajorMinorVersion.major']]
      minor: $[stageDependencies.GetVersion.Get_Major_Minor_From_Version_File.outputs['GetMajorMinorVersion.minor']]
      semantic: $(major).$(minor)
      buildNum: $[counter(variables['semantic'], 0)]
    steps:
      - checkout: self
      - task: PowerShell@2
        inputs:
          targetType: 'inline'
          script: |
            Write-Host "The value is $(major)"
            Write-Host "##vso[build.updatebuildnumber]$(major).$(minor).$(buildNum)"
          name: 'SetMasterBuildName'       

- stage: TagRelease
  # when done testing update branch to master
  condition: and(eq(variables['Build.SourceBranchName'], 'convert-to-commonjs-module-with-tags-implementation'), eq(variables['Build.Reason'], 'IndividualCI'))
  jobs:
    - job: Tag
      variables:
        semantic: $major.$minor
        buildNum: $[counter(variables['semantic'], 0)]
      workspace:
        clean: all
      # variables:
      #   patch: $[counter(variables['minor'], 0)]
      steps:
        - checkout: self
          persistCredentials: true
        - task: PowerShell@2
          inputs:
            targetType: 'inline'
            script: |
              if ($(git tag -l $(major).$(minor).$(buildNum))) {
                Write-Output "$(major).$(minor).$(buildNum) already released" 
              }
              else {
                git tag $(major).$(minor).$(buildNum)
                git push origin $(major).$(minor).$(buildNum)
              }
            workingDirectory: $(Build.SourcesDirectory)
            displayName: 'Conditionally  Tag'

修复方案 #

1. 补全TagRelease阶段的跨阶段变量引用 #

TagRelease阶段的Tag作业未定义从GetVersion阶段传递的major和minor变量，导致脚本无法解析这两个值，将其当作PowerShell命令执行报错。

修复： 在Tag作业的variables块中添加变量定义：

variables:
  major: $[stageDependencies.GetVersion.Get_Major_Minor_From_Version_File.outputs['GetMajorMinorVersion.major']]
  minor: $[stageDependencies.GetVersion.Get_Major_Minor_From_Version_File.outputs['GetMajorMinorVersion.minor']]

2. 修正变量引用语法错误 #

原TagRelease阶段中semantic: $major.$minor使用了错误的变量引用格式，Azure Pipelines中需用$(变量名)格式引用变量，而非$变量名。

修复： 将semantic定义改为：

semantic: $(major).$(minor)

3. 修复后的完整TagRelease阶段配置 #

- stage: TagRelease
  condition: and(eq(variables['Build.SourceBranchName'], 'convert-to-commonjs-module-with-tags-implementation'), eq(variables['Build.Reason'], 'IndividualCI'))
  jobs:
    - job: Tag
      variables:
        major: $[stageDependencies.GetVersion.Get_Major_Minor_From_Version_File.outputs['GetMajorMinorVersion.major']]
        minor: $[stageDependencies.GetVersion.Get_Major_Minor_From_Version_File.outputs['GetMajorMinorVersion.minor']]
        semantic: $(major).$(minor)
        buildNum: $[counter(variables['semantic'], 0)]
      workspace:
        clean: all
      steps:
        - checkout: self
          persistCredentials: true
        - task: PowerShell@2
          inputs:
            targetType: 'inline'
            script: |
              $tagName = "$(major).$(minor).$(buildNum)"
              if (git tag -l $tagName) {
                Write-Output "$tagName already released" 
              }
              else {
                git tag $tagName
                git push origin $tagName
              }
            workingDirectory: $(Build.SourcesDirectory)
            displayName: 'Conditionally Tag'

额外优化建议 #

在PowerShell脚本中，建议将流水线变量赋值给本地变量后再使用，避免多次解析可能出现的问题，同时提升代码可读性（如上述修复中使用$tagName变量）。

内容的提问来源于stack exchange，提问作者Sagufa Khanam