diff --git a/.azure-pipelines/azure-pipelines-UpgrateVersion.yml b/.azure-pipelines/azure-pipelines-UpgrateVersion.yml
index 03593c551c..6e11e3826e 100644
--- a/.azure-pipelines/azure-pipelines-UpgrateVersion.yml
+++ b/.azure-pipelines/azure-pipelines-UpgrateVersion.yml
@@ -45,8 +45,11 @@ parameters:
 stages:
 - stage: Build
   variables:
-    CACHE_MODE: none
-    VERSION_CONTROL_OPTIONS: 'SONIC_VERSION_CONTROL_COMPONENTS='
+    - name: CACHE_MODE
+      value: none
+    - name: VERSION_CONTROL_OPTIONS
+      value: 'SONIC_VERSION_CONTROL_COMPONENTS='
+    - template: .azure-pipelines/template-variables.yml@buildimage
   jobs:
   - template: azure-pipelines-build.yml
     parameters:
diff --git a/.azure-pipelines/docker-sonic-slave-template.yml b/.azure-pipelines/docker-sonic-slave-template.yml
index a3d2d17dd0..24b16bd64b 100644
--- a/.azure-pipelines/docker-sonic-slave-template.yml
+++ b/.azure-pipelines/docker-sonic-slave-template.yml
@@ -45,7 +45,10 @@ jobs:
   pool: ${{ parameters.pool }}
   steps:
   - template: cleanup.yml
-  - template: .azure-pipelines/template-clean-sonic-slave.yml@buildimage
+  - ${{ if eq(variables['Build.Reason'], 'PullRequest') }}:
+    - template: template-clean-sonic-slave.yml
+  - ${{ else }}:
+    - template: .azure-pipelines/template-variables.yml@buildimage
   - checkout: self
     clean: true
     submodules: recursive
diff --git a/.azure-pipelines/official-build.yml b/.azure-pipelines/official-build.yml
index af43730915..8fe33e7706 100644
--- a/.azure-pipelines/official-build.yml
+++ b/.azure-pipelines/official-build.yml
@@ -18,9 +18,20 @@ schedules:
     - 201911
     - 201811
 
+resources:
+  repositories:
+  - repository: buildimage
+    type: github
+    name: Azure/sonic-buildimage
+    ref: master
+    endpoint: build
+
 trigger: none
 pr: none
 
+variables:
+- template: .azure-pipelines/template-variables.yml@buildimage
+
 stages:
 - stage: Build
   pool: sonicbld
diff --git a/.azure-pipelines/template-clean-sonic-slave.yml b/.azure-pipelines/template-clean-sonic-slave.yml
new file mode 100644
index 0000000000..ddb8c8e48f
--- /dev/null
+++ b/.azure-pipelines/template-clean-sonic-slave.yml
@@ -0,0 +1,10 @@
+steps:
+- script: |
+    set -x
+    containers=$(docker container ls -aq)
+    [ -n "$containers" ] && docker container rm -f $containers
+    docker images | grep "^<none>" | awk '{print$3}' | xargs -i docker rmi {}
+    images=$(docker images 'sonic-slave-*' -a -q)
+    [ -n "$images" ] && docker rmi -f $images
+    exit 0
+  displayName: 'Cleanup sonic slave'
diff --git a/.azure-pipelines/template-variables.yml b/.azure-pipelines/template-variables.yml
new file mode 100644
index 0000000000..f28768e39e
--- /dev/null
+++ b/.azure-pipelines/template-variables.yml
@@ -0,0 +1,2 @@
+variables:
+  DEFAULT_CONTAINER_REGISTRY: 'publicmirror.azurecr.io'
diff --git a/azure-pipelines.yml b/azure-pipelines.yml
index b3aa563307..1f0fd998d8 100644
--- a/azure-pipelines.yml
+++ b/azure-pipelines.yml
@@ -30,9 +30,18 @@ resources:
     type: github
     name: Azure/sonic-mgmt
     endpoint: build
+  - repository: buildimage
+    type: github
+    name: Azure/sonic-buildimage
+    endpoint: build
+    ref: master
 
 variables:
 - template: .azure-pipelines/azure-pipelines-repd-build-variables.yml
+- ${{ if eq(variables['Build.Reason'], 'PullRequest') }}:
+  - template: .azure-pipelines/template-variables.yml
+- ${{ else }}:
+  - template: .azure-pipelines/template-variables.yml@buildimage
 - name: CACHE_MODE
   value: rcache