I don't have permission to add a pipeline so let's try to filter them out

I wish there was a built in method for yml to do this instead. For example, pr: has exclude which lets us not run the ci if changes are only in certain components. Ideally we could do something similar for the stages and condition them based on dnup/ non dnup changes? Note that we still need to have the .vsts-pr.yml file as the root pipeline file, and we can't just exclude running the entire thing as it controls the SDK pipeline as well.

Author: nagilson

.vsts-pr.yml

@@ -24,56 +24,98 @@ variables:
 - template: /eng/pipelines/templates/variables/sdk-defaults.yml
 # Variables used: DncEngPublicBuildPool
 - template: /eng/common/templates/variables/pool-providers.yml
+# Variable to determine if PR changes are limited to dnup paths
+- name: isDnupOnlyChanges
+  value: $[in(variables['Build.Reason'], 'PullRequest', 'Manual')]
 
 resources:
   containers:
   - container: azureLinux30Amd64
     image: mcr.microsoft.com/dotnet-buildtools/prereqs:azurelinux-3.0-net10.0-build-amd64
 
 stages:
-############### BUILD STAGE ###############
-- stage: build
-  displayName: Build
+############### FILTER CHANGES STAGE ###############
+- stage: filter_changes
+  displayName: Filter PR Changes
   jobs:
-  ############### WINDOWS ###############
-  - template: /eng/pipelines/templates/jobs/sdk-job-matrix.yml@self
+  - template: /eng/pipelines/templates/jobs/filter-dnup-changes.yml
     parameters:
       pool:
         name: $(DncEngPublicBuildPool)
         demands: ImageOverride -equals windows.vs2022.amd64.open
+
+############### BUILD STAGE ###############
+- stage: build
+  displayName: Build
+  dependsOn: filter_changes
+  variables:
+    isDnupOnlyChanges: $[ stageDependencies.filter_changes.FilterDnupChanges.outputs['SetDnupFlag.isDnupOnlyChanges'] ]
+  jobs:
+  # If changes are dnup-only, run only dnup tests
+  - ${{ if eq(variables['isDnupOnlyChanges'], 'true') }}:
+    ############### DNUP TESTS ONLY ###############
+    - template: /eng/pipelines/templates/jobs/dnup-tests.yml
+      parameters:
+        pool:
+          name: $(DncEngPublicBuildPool)
+          demands: ImageOverride -equals windows.vs2022.amd64.open
         os: windows
-      helixTargetQueue: windows.amd64.vs2022.pre.open
 
-  ############### LINUX ###############
-  - template: /eng/pipelines/templates/jobs/sdk-job-matrix.yml
-    parameters:
-      pool:
-        name: $(DncEngPublicBuildPool)
-        demands: ImageOverride -equals build.ubuntu.2204.amd64.open
+    - template: /eng/pipelines/templates/jobs/dnup-tests.yml
+      parameters:
+        pool:
+          name: $(DncEngPublicBuildPool)
+          demands: ImageOverride -equals build.ubuntu.2204.amd64.open
         os: linux
-      helixTargetQueue: ubuntu.2204.amd64.open
 
-  ############### MACOS ###############
-  - template: /eng/pipelines/templates/jobs/sdk-job-matrix.yml
-    parameters:
-      pool:
-        name: Azure Pipelines
-        vmImage: macOS-latest
+    - template: /eng/pipelines/templates/jobs/dnup-tests.yml
+      parameters:
+        pool:
+          name: Azure Pipelines
+          vmImage: macOS-latest
         os: macOS
-      helixTargetQueue: osx.15.amd64.open
-  ### ARM64 ###
-  - ${{ if eq(parameters.enableArm64Job, true) }}:
+
+  # Otherwise run the full SDK matrix
+  - ${{ if ne(variables['isDnupOnlyChanges'], 'true') }}:
+    ############### WINDOWS ###############
+    - template: /eng/pipelines/templates/jobs/sdk-job-matrix.yml@self
+      parameters:
+        pool:
+          name: $(DncEngPublicBuildPool)
+          demands: ImageOverride -equals windows.vs2022.amd64.open
+          os: windows
+        helixTargetQueue: windows.amd64.vs2022.pre.open
+
+    ############### LINUX ###############
+    - template: /eng/pipelines/templates/jobs/sdk-job-matrix.yml
+      parameters:
+        pool:
+          name: $(DncEngPublicBuildPool)
+          demands: ImageOverride -equals build.ubuntu.2204.amd64.open
+          os: linux
+        helixTargetQueue: ubuntu.2204.amd64.open
+
+    ############### MACOS ###############
     - template: /eng/pipelines/templates/jobs/sdk-job-matrix.yml
       parameters:
         pool:
           name: Azure Pipelines
           vmImage: macOS-latest
           os: macOS
-        helixTargetQueue: osx.13.arm64.open
-        macOSJobParameterSets:
-        - categoryName: TestBuild
-          targetArchitecture: arm64
-          runtimeIdentifier: osx-arm64
+        helixTargetQueue: osx.15.amd64.open
+    ### ARM64 ###
+    - ${{ if eq(parameters.enableArm64Job, true) }}:
+      - template: /eng/pipelines/templates/jobs/sdk-job-matrix.yml
+        parameters:
+          pool:
+            name: Azure Pipelines
+            vmImage: macOS-latest
+            os: macOS
+          helixTargetQueue: osx.13.arm64.open
+          macOSJobParameterSets:
+          - categoryName: TestBuild
+            targetArchitecture: arm64
+            runtimeIdentifier: osx-arm64
 
   ############### DOTNET-FORMAT ###############
   - template: /eng/dotnet-format/dotnet-format-integration.yml

eng/pipelines/templates/jobs/filter-dnup-changes.yml

@@ -0,0 +1,48 @@
+# Filter job to check if changes are dnup-only
+parameters:
+  pool: {}
+
+jobs:
+- job: FilterDnupChanges
+  displayName: Filter dnup-only Changes
+  pool: ${{ parameters.pool }}
+
+  steps:
+  - checkout: self
+    fetchDepth: 0
+
+  - powershell: |
+      # Initialize the variable to false
+      $isDnupOnly = $true
+
+      # If PR, get the changed files
+      if ($env:BUILD_REASON -eq 'PullRequest') {
+        Write-Host "This is a PR build, checking changed files..."
+        $targetBranch = "$env:SYSTEM_PULLREQUEST_TARGETBRANCH"
+        Write-Host "Target branch: $targetBranch"
+
+        # Get changed files in the PR
+        $changedFiles = git diff --name-only origin/$targetBranch..HEAD
+
+        Write-Host "Changed files:"
+        $changedFiles | ForEach-Object { Write-Host "  $_" }
+
+        # Check if any changed files are outside dnup paths
+        foreach ($file in $changedFiles) {
+          if (-not ($file.StartsWith("src/Installer/") -or $file.StartsWith("test/dnup.Tests/"))) {
+            Write-Host "Found change outside dnup paths: $file"
+            $isDnupOnly = $false
+            break
+          }
+        }
+      } else {
+        # If not a PR, we assume it's not dnup-only
+        Write-Host "This is not a PR build, setting isDnupOnly to false"
+        $isDnupOnly = $false
+      }
+
+      # Set the variable for later stages
+      Write-Host "##vso[task.setvariable variable=isDnupOnlyChanges;isOutput=true]$isDnupOnly"
+      Write-Host "isDnupOnlyChanges = $isDnupOnly"
+    displayName: Check if changes are dnup-only
+    name: SetDnupFlag