Detect if Dockerfile for docker-ptf is modified (#23869)

Why I did it
Detect changes in PR for dockers/docker-ptf/Dockerfile.j2 and pass flag to sonic-mgmt tests. This change will be used in sonic-mgmt tests to download the PR built docker-ptf.gz image instead of testing against the latest tag which was published from master branch builds.

Work item tracking
Microsoft ADO (number only): 34093272

How I did it
Added code to detect change and pass PTF_MODIFIED flag.

How to verify it
Can be tested after PR merges in sonic-mgmt and elastic test.

Tested branch (Please provide the tested image version)
NA

Description for the changelog
[docker-ptf] Detect if PR modifies docker-ptf Dockerfile.

Pass flag to sonic-mgmt test stage in pipeline if PR modifies docker-ptf Dockerfile.

Author: opcoder0

.azure-pipelines/azure-pipelines-image-template.yml

@@ -82,6 +82,26 @@ jobs:
           BUILD_REASON=$(Build.Reason)
           echo "Build.Reason = $BUILD_REASON"
           echo "Build.DefinitionName = $BUILD_DEFINITIONNAME"
+          if [[ "$BUILD_REASON" == "PullRequest" ]]; then
+            echo "Checking for changes to dockers/docker-ptf/Dockerfile.j2 in PR..."
+            # Get the target branch and check for changes
+            TARGET_BRANCH="origin/$(System.PullRequest.TargetBranch)"
+            echo "Comparing against target branch: $TARGET_BRANCH"
+            # Fetch target branch to ensure we have the latest
+            git fetch origin $(System.PullRequest.TargetBranch)
+            # Check if docker-ptf Dockerfile.j2 has changes
+            if git diff --name-only $TARGET_BRANCH...HEAD | grep -q "dockers/docker-ptf/Dockerfile.j2"; then
+              echo "docker-ptf/Dockerfile.j2 has been modified in this PR"
+              echo "##vso[task.setvariable variable=PTF_MODIFIED;isOutput=true]true"
+            else
+              echo "docker-ptf/Dockerfile.j2 has not been modified in this PR"
+              echo "##vso[task.setvariable variable=PTF_MODIFIED;isOutput=true]false"
+            fi
+          else
+            echo "Not a PR build, setting PTF_MODIFIED to false"
+            echo "##vso[task.setvariable variable=PTF_MODIFIED;isOutput=true]false"
+          fi
+
           if [[ "$BUILD_REASON" != "PullRequest" && "$BUILD_DEFINITIONNAME" == "Azure.sonic-buildimage.official.vs" ]]
           then
             PORT=443
@@ -100,6 +120,7 @@ jobs:
           mv target/* $(Build.ArtifactStagingDirectory)/target/
         env:
           REGISTRY_PASSWD: $(REGISTRY_PASSWD)
+        name: PublishAndSetPtfTag
         displayName: Publish to Docker Registry and Copy Artifacts
         condition: always()
       - publish:  $(Build.ArtifactStagingDirectory)

azure-pipelines.yml

@@ -105,6 +105,8 @@ stages:
     value: veos_vtb
   - name: testbed_file
     value: vtestbed.csv
+  - name: PTF_MODIFIED
+    value: $[ coalesce(stageDependencies.BuildVS.vs.outputs['PublishAndSetPtfTag.PTF_MODIFIED'], 'false') ]
 
 # For every test job:
 # continueOnError: false means it's a required test job and will block merge if it fails
@@ -207,6 +209,7 @@ stages:
           KVM_IMAGE_BRANCH: $(BUILD_BRANCH)
           MGMT_BRANCH: $(BUILD_BRANCH)
           COMMON_EXTRA_PARAMS: "--disable_sai_validation "
+          PTF_MODIFIED: ${{ eq(variables['PTF_MODIFIED'], 'true') }}
 
   - job: impacted_area_t0_2vlans_elastictest
     displayName: "impacted-area-kvmtest-t0-2vlans by Elastictest"
@@ -235,6 +238,7 @@ stages:
           KVM_IMAGE_BRANCH: $(BUILD_BRANCH)
           MGMT_BRANCH: $(BUILD_BRANCH)
           COMMON_EXTRA_PARAMS: "--disable_sai_validation "
+          PTF_MODIFIED: ${{ eq(variables['PTF_MODIFIED'], 'true') }}
 
   - job: impacted_area_t1_lag_elastictest
     displayName: "impacted-area-kvmtest-t1-lag by Elastictest"
@@ -264,6 +268,7 @@ stages:
           KVM_IMAGE_BRANCH: $(BUILD_BRANCH)
           MGMT_BRANCH: $(BUILD_BRANCH)
           COMMON_EXTRA_PARAMS: "--disable_sai_validation "
+          PTF_MODIFIED: ${{ eq(variables['PTF_MODIFIED'], 'true') }}
 
   - job: impacted_area_dualtor_elastictest
     displayName: "impacted-area-kvmtest-dualtor by Elastictest"
@@ -293,6 +298,7 @@ stages:
           COMMON_EXTRA_PARAMS: "--disable_loganalyzer --disable_sai_validation "
           KVM_IMAGE_BRANCH: $(BUILD_BRANCH)
           MGMT_BRANCH: $(BUILD_BRANCH)
+          PTF_MODIFIED: ${{ eq(variables['PTF_MODIFIED'], 'true') }}
 
   - job: impacted_area_multi_asic_elastictest
     displayName: "impacted-area-kvmtest-multi-asic-t1 by Elastictest"
@@ -321,6 +327,7 @@ stages:
           KVM_IMAGE_BRANCH: $(BUILD_BRANCH)
           MGMT_BRANCH: $(BUILD_BRANCH)
           COMMON_EXTRA_PARAMS: "--disable_sai_validation "
+          PTF_MODIFIED: ${{ eq(variables['PTF_MODIFIED'], 'true') }}
 
   - job: impacted_area_t0_sonic_elastictest
     displayName: "impacted-area-kvmtest-t0-sonic by Elastictest"
@@ -350,6 +357,7 @@ stages:
           COMMON_EXTRA_PARAMS: "--neighbor_type=sonic --disable_sai_validation "
           VM_TYPE: vsonic
           MGMT_BRANCH: $(BUILD_BRANCH)
+          PTF_MODIFIED: ${{ eq(variables['PTF_MODIFIED'], 'true') }}
           SPECIFIC_PARAM: '[
             {"name": "bgp/test_bgp_fact.py", "param": "--neighbor_type=sonic --enable_macsec --macsec_profile=128_SCI,256_XPN_SCI"},
             {"name": "macsec", "param": "--neighbor_type=sonic --enable_macsec --macsec_profile=128_SCI,256_XPN_SCI"}
@@ -381,6 +389,7 @@ stages:
           KVM_IMAGE_BRANCH: $(BUILD_BRANCH)
           COMMON_EXTRA_PARAMS: "--disable_sai_validation "
           MGMT_BRANCH: $(BUILD_BRANCH)
+          PTF_MODIFIED: ${{ eq(variables['PTF_MODIFIED'], 'true') }}
           SPECIFIC_PARAM: '[
             {"name": "dash/test_dash_vnet.py", "param": "--skip_dataplane_checking"}
             ]'