[ci]: use the same snapshot of pytests as the docker-sonic-vs image (sonic-net#1545)

in case sonic-swss build failure, the docker-sonic-vs may not
match exactly the same pytest checkout from master

Signed-off-by: Guohan Lu <[email protected]>

Author: lguohan

.azure-pipelines/test-docker-sonic-vs-template.yml

@@ -30,14 +30,22 @@ jobs:
       runBranch: 'refs/heads/master'
     displayName: "Download sonic swss common deb packages"
 
+  - task: DownloadPipelineArtifact@2
+    inputs:
+      source: specific
+      project: build
+      pipeline: 15
+      artifact: sonic-swss-pytests
+      runVersion: 'latestFromBranch'
+      runBranch: 'refs/heads/master'
+    displayName: "Download sonic swss pytests"
+
   - checkout: self
-    displayName: "Checkout sonic-swss-common"
-  - checkout: sonic-swss
-    displayName: "Checkout sonic-swss"
+    displayName: "Checkout sonic-utilities"
 
   - script: |
       set -x
-      sudo sonic-utilities/.azure-pipelines/build_and_install_module.sh
+      sudo .azure-pipelines/build_and_install_module.sh
 
       sudo apt-get install -y libhiredis0.14
       sudo dpkg -i --force-confask,confnew ../libswsscommon_1.0.0_amd64.deb || apt-get install -f
@@ -54,7 +62,11 @@ jobs:
       sudo docker load -i ../docker-sonic-vs.gz
       docker ps
       ip netns list
-      pushd sonic-swss/tests
+      cd ../
+      mkdir -p sonic-swss
+      pushd sonic-swss
+      tar xf ../pytest.tgz
+      pushd tests
       sudo py.test -v --force-flaky --junitxml=tr.xml --imgname=docker-sonic-vs:$(Build.DefinitionName).$(Build.BuildNumber)
     displayName: "Run vs tests"
 
@@ -65,7 +77,7 @@ jobs:
     condition: always()
 
   - script: |
-      cp -r sonic-swss/tests/log $(Build.ArtifactStagingDirectory)/
+      cp -r ../sonic-swss/tests/log $(Build.ArtifactStagingDirectory)/
     displayName: "Collect logs"
     condition: always()