在模板参数中使用任务输出变量

Question

我管道中的第一阶段检查哪些服务实际发生了变化。这是为了通过避免在没有更改的情况下重建、重新测试、重新部署服务来加快管道。

这是那个阶段的changed.yaml：

parameters:
- name: comparedTo
  default: ''

stages:
- stage: Changed
  displayName: Check for changes in services and configs...
  jobs:
  - job: Changes
    displayName: Checking for changes in services and configs...
    steps:
    - bash: |
        mapfile -t changed < <(git diff  HEAD ${{ parameters.comparedTo }} --name-only | awk -F'/' 'NF!=1{print }' | sort -u)
        servicesChanged=()
        configChanged=()
        echo ""
        echo "Total Changed: ${#changed[@]}"
        for i in "${changed[@]}"
        do
          echo $i
          if [[ $i == 'admin' ]]; then
            echo "##vso[task.setvariable variable=adminChanged;isOutput=True]true"
            servicesChanged+=("admin")
          elif [[ $i == 'admin-v2' ]]; then
            echo "##vso[task.setvariable variable=adminV2Changed;isOutput=True]true"
            servicesChanged+=("admin-v2")
          elif [[ $i == 'api' ]]; then
            echo "##vso[task.setvariable variable=apiChanged;isOutput=True]true"
            servicesChanged+=("api")
          elif [[ $i == 'client' ]]; then
            echo "##vso[task.setvariable variable=clientChanged;isOutput=True]true"
            servicesChanged+=("client")
          elif [[ $i == 'k8s' ]]; then
            echo "##vso[task.setvariable variable=k8sChanged;isOutput=True]true"
            configsChanged+=("k8s")
          elif [[ $i == 'pipelines' ]]; then
            echo "##vso[task.setvariable variable=pipelineChanged;isOutput=True]true"
            configsChanged+=("pipelines")
          fi
        done
        echo ""
        echo "Services Changed: ${#servicesChanged[@]}"
        for i in "${servicesChanged[@]}"
        do
          echo $i
        done
        echo ""
        echo "Configs Changed: ${#configsChanged[@]}"
        for i in "${configsChanged[@]}"
        do
          echo $i
        done
        if [[ ${#servicesChanged[@]} > 0 ]]; then
          echo ""
          echo "Any services changed: True"
          echo "##vso[task.setvariable variable=anyServicesChanged;isOutput=true]true"
          echo "##vso[task.setvariable variable=servicesChanged;isOutput=true]${servicesChanged[@]}"
        fi
        if [[ ${#configsChanged[@]} > 0 ]]; then
          echo ""
          echo "Any configs changed: True"
          echo "##vso[task.setvariable variable=anyConfigsChanged;isOutput=true]true"
          echo "##vso[task.setvariable variable=configsChanged;isOutput=true]${configsChanged[@]}"
        fi
        echo ""
      name: detectChanges

如您所见，它创建了许多任务输出变量：

# This just indicates if the service has changed: true/false
echo "##vso[task.setvariable variable=<service-name>;isOutput=True]true"

# This should be creating a an output variable that is an array of the services that have changed
echo "##vso[task.setvariable variable=servicesChanged;isOutput=true]${servicesChanged[@]}"

所以我给了自己两个选择：每个服务只 true/false 或迭代（以某种方式）已更改的服务数组。

每个阶段基本有以下形式：

# pr.yaml
...
- template: templates/unitTests.yaml
  parameters: 
    services: 
    - api
    - admin
    - admin-v2
    - client
...

parameters:
- name: services
  type: object
  default: []

stages:
- stage: UnitTests
  displayName: Run unit tests on service...
  dependsOn: Changed
  condition: succeeded()
  jobs:
  - job: UnitTests
    condition: or(eq(stageDependencies.Changed.Changes.outputs['detectChanges.anyServicesChanged'], true), eq(variables['Build.Reason'], 'Manual'))
    displayName: Running unit tests...
    steps:
    - ${{ each service in parameters.services }}:
      - bash: |
          echo "Now running ${{ service }} unit tests..."

这是我到目前为止尝试过的方法和我遇到的错误：

将每个服务有条件地添加到服务数组或添加已更改服务的数组：

- template: templates/changed.yaml
  parameters:
    comparedTo: origin/production
- template: templates/unitTests.yaml
  dependsOn: Changed
  parameters: 
    services: 
    - ${{ if eq(stageDependencies.Changed.Changes.outputs['detectChanges.apiChanged'], true) }}
      - api
    - ${{ if eq(stageDependencies.Changed.Changes.outputs['detectChanges.adminChanged'], true) }}
      - admin
    - ${{ if eq(stageDependencies.Changed.Changes.outputs['detectChanges.adminV2Changed'], true) }}
      - admin-v2
    - ${{ if eq(stageDependencies.Changed.Changes.outputs['detectChanges.clientChanged'], true) }}
      - client

或者...

- template: templates/changed.yaml
  parameters:
    comparedTo: origin/production
- template: templates/unitTests.yaml
  dependsOn: Changed
  parameters: 
    services: 
    - ${{ if eq(dependencies.Changed.outputs['Changes.detectChanges.apiChanged'], true) }}
      - api
    - ${{ if eq(dependencies.Changed.outputs['Changes.detectChanges.adminChanged'], true) }}
      - admin
    - ${{ if eq(dependencies.Changed.outputs['Changes.detectChanges.adminV2Changed'], true) }}
      - admin-v2
    - ${{ if eq(dependencies.Changed.outputs['Changes.detectChanges.clientChanged'], true) }}
      - client

或者...

- template: templates/changed.yaml
  parameters:
    comparedTo: origin/production
- template: templates/unitTests.yaml
  dependsOn: Changed
  parameters: 
    services: 
    - $[ stageDependencies.Changed.Changes.outputs['detectChanges.servicesChanged'] ]

这导致：

An error occurred while loading the YAML build pipeline. Object reference not set to an instance of an object.

我知道 variables: 只会接受字符串而不是数组。

一个解决方案是为每个 true/false 变量设置一个 variables:，然后根据 parameters.services 以及任务输出变量是否为 true 设置条件.

有什么建议吗？

参考：

Answer 1

模板表达式${{}}在编译时求值（在作业运行之前），这意味着它无法访问在运行时动态设置的变量（工作开始后）。所以你不能在上面的场景中使用模板表达式 ${{}} 。请参阅以下来自 here 的描述。

Within a template expression, you have access to the parameters context that contains the values of parameters passed in. Additionally, you have access to the variables context that contains all the variables specified in the YAML file plus many of the predefined variables (noted on each variable in that topic). Importantly, it doesn't have runtime variables such as those stored on the pipeline or given when you start a run. Template expansion happens very early in the run, so those variables aren't available

您可以使用条件作为解决方法。您需要添加多个任务以根据条件执行。请参阅以下示例：

- template: templates/changed.yaml
  parameters:
    comparedTo: origin/production
- template: templates/unitTests.yaml
  dependsOn: Changed

#unitTests.yaml

stages:
- stage: UnitTests
  displayName: Run unit tests on service...
  dependsOn: Changed
  condition: succeeded()
  jobs:
  - job: UnitTests
    condition: or(eq(stageDependencies.Changed.Changes.outputs['detectChanges.anyServicesChanged'], true), eq(variables['Build.Reason'], 'Manual'))
    displayName: Running unit tests...
    
    variables:
      changedServices: $[stageDependencies.Changed.Changes.outputs['detectChanges.servicesChanged']]
    
    steps:
    - bash: |
         echo "Now running api unit tests..."
      name: Api-unit-test
      conidtion: contains(variables['changedServices'], 'api')
   
    - bash: |
         echo "Now running admin unit tests..."
      name: admin-unit-test
      conidtion: contains(variables['changedServices'], 'admin')
    
    - bash: |
         echo "Now running client unit tests..."
      name: client-unit-test
      conidtion: contains(variables['changedServices'], 'client')

另一种解决方法是将您的管道分成两个管道。第一流水线到运行 Changed 阶段。然后调用 rest api in a script task to trigger the second pipeline and pass the variables in the request body. See this 类似的线程。

在模板参数中使用任务输出变量

Using task output variables in template parameters

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