Azure Pipelines - Run Stages When Certain Files Are Changed

analyze-changes.yml

parameters:
- name: searchPattern
  type: string
- name: setVariableNamed
  type: string
- name: publishAsArtifactNamed
  type: string
  default: SkipPublishChanges

steps:
- powershell: |
    $found = 'No';

    # grab all changes files in last commit
    $data = git diff --name-only HEAD~ HEAD
    $files = $data.Split([System.Environment]::NewLineCharacter)

    # filter all files looking for ones that match the searchpattern
    $files = $files | where {$_ -like '${{ parameters.searchPattern }}'}

    # if there are any files under the given search pattern
    if ($files.count -gt 0) {
        Write-Host 'Located: '
        Write-Host $files
        $found = 'Yes';
    } else {
        Write-Host "No files found matching ${{ parameters.searchPattern }}"
    }

    # if they indicated they would like to configure a variable with the outcome
    if (![string]::IsNullOrEmpty('${{ parameters.setVariableNamed }}')) {
        Write-Host "##vso[task.setvariable variable=${{ parameters.setVariableNamed }};isOutput=true]$found"
    }

    # Copy all changes to a folder to publish them
    if (![string]::IsNullOrEmpty('${{parameters.publishAsArtifactNamed}}')) {
      New-Item -Type Directory "_${{parameters.publishAsArtifactNamed}}"
      $path = "_${{parameters.publishAsArtifactNamed}}" + [IO.Path]::DirectorySeparatorChar
      foreach ($i in $files) {
        $tgt = $path + $i
        Copy-Item "$i" "$tgt"
      }
    }
  name: Changes
  displayName: Analyze Changes

- task: PublishBuildArtifacts@1
  displayName: Publish Changes
  condition: ${{ ne(parameters.publishAsArtifactNamed, 'SkipPublishChanges') }}
  inputs:
    pathToPublish: '_${{parameters.publishAsArtifactNamed}}'
    artifactName: ${{parameters.publishAsArtifactNamed}}

azure-pipelines.yml

trigger: none

pool: 
  vmImage: windows-latest

stages:
- stage: AnalyzeStage
  jobs:
  - job: FirstJob
    steps:
    - template: analyze-changes.yml
      parameters:
        searchPattern: '*.sql'
        setVariableNamed: 'SqlChangesFound'
        publishAsArtifactNamed: 'SqlChanges'
    - powershell: |
        Write-Host 'Current Value: $(Changes.SqlChangesFound)'
  - job: SecondJob
    variables:
      SqlChangesFound: $[dependencies.FirstJob.outputs['Changes.SqlChangesFound']]
    dependsOn: FirstJob
    steps:
    - powershell: |
        Write-Host 'Current Value: $(SqlChangesFound)'

- stage: ConditionalSqlStage
  condition: eq(dependencies.AnalyzeStage.outputs['FirstJob.Changes.SqlChangesFound'], 'Yes')
  dependsOn: AnalyzeStage
  jobs:
  - job: SomeSqlWork
    variables:
      SqlChangesFound: $[stageDependencies.AnalyzeStage.FirstJob.outputs['Changes.SqlChangesFound']]
    steps:
    - powershell: |
        Write-Host 'Value From another stage: $(SqlChangesFound)'