Use containers, also use phases level variables

.vsts-ci.yml

@@ -1,3 +1,16 @@
+variables:
+  _HelixType: build/product
+  ${{ if or(eq(variables['System.TeamProject'], 'public'), in(variables['Build.Reason'], 'PullRequest')) }}:
+    _HelixSource: pr/dotnet/arcade/$(Build.SourceBranch)
+  ${{ if and(ne(variables['System.TeamProject'], 'public'), notin(variables['Build.Reason'], 'PullRequest')) }}:
+    _TeamName: DotNetCore
+    _HelixSource: official/dotnet/arcade/$(Build.SourceBranch)
+
+resources:
+  containers:
+  - container: LinuxContainer
+    image: microsoft/dotnet-buildtools-prereqs:ubuntu-14.04-cross-0cd4667-20170319080304
+
 phases:
   - template: /eng/build.yml
     parameters:
@@ -32,7 +45,7 @@ phases:
     parameters:
       name: Linux
       queue:
-        # Temporarily, use the linux pool while the hosted preview doesn't have docker support.
+        container: LinuxContainer
         ${{ if or(eq(variables['System.TeamProject'], 'public'), in(variables['Build.Reason'], 'PullRequest')) }}:
           name: dnceng-linux-external-temp
         ${{ if and(ne(variables['System.TeamProject'], 'public'), notin(variables['Build.Reason'], 'PullRequest')) }}:
@@ -49,8 +62,6 @@ phases:
             _PublishType: none
             _SignType: none
             _DotNetPublishToBlobFeed : false
-      variables:
-        _PREVIEW_VSTS_DOCKER_IMAGE: microsoft/dotnet-buildtools-prereqs:ubuntu-14.04-cross-0cd4667-20170319080304
 
   - ${{ if and(ne(variables['System.TeamProject'], 'public'), notin(variables['Build.Reason'], 'PullRequest')) }}:
     - template: /eng/common/templates/phases/publish-build-assets.yml

eng/build.yml

@@ -29,28 +29,24 @@ phases:
 
     variables: 
       ${{ insert }}: ${{ parameters.variables }}
-      _HelixType: build/product
       _HelixBuildConfig: $(_BuildConfig)
       # Only enable publishing in non-public, non PR scenarios.
       ${{ if and(ne(variables['System.TeamProject'], 'public'), notin(variables['Build.Reason'], 'PullRequest')) }}:
         # This should be changed to an isolated blob feed per-build.
         # Right now a manual build of a random branch would get published alongside the normal branch artifacts.
         _PublishBlobFeedUrl: https://dotnetfeed.blob.core.windows.net/dotnet-core/index.json
-        _TeamName: DotNetCore
         _SignArgs: /p:DotNetSignType=$(_SignType) /p:TeamName=$(_TeamName)
         _PublishArgs: /p:DotNetPublishBlobFeedKey=$(dotnetfeed-storage-access-key-1) 
           /p:DotNetPublishBlobFeedUrl=$(_PublishBlobFeedUrl) 
           /p:DotNetPublishToBlobFeed=$(_DotNetPublishToBlobFeed)
           /p:DotNetSymbolServerTokenMsdl=$(microsoft-symbol-server-pat)
           /p:DotNetSymbolServerTokenSymWeb=$(symweb-symbol-server-pat)
-        _HelixSource: official/dotnet/arcade/$(Build.SourceBranch)
         _OfficialBuildIdArgs: /p:OfficialBuildId=$(BUILD.BUILDNUMBER)
       # else
       ${{ if or(eq(variables['System.TeamProject'], 'public'), in(variables['Build.Reason'], 'PullRequest')) }}:
         _PublishArgs: ''
         _OfficialBuildIdArgs: ''
         _SignArgs: ''
-        _HelixSource: pr/dotnet/arcade/$(Build.SourceBranch)
 
     steps:
     - ${{ if and(ne(variables['System.TeamProject'], 'public'), notin(variables['Build.Reason'], 'PullRequest')) }}:

eng/common/templates/phases/base.yml

@@ -41,7 +41,8 @@ phases:
   queue: ${{ parameters.queue }}
 
   ${{ if ne(parameters.variables, '') }}:
-    variables: ${{ parameters.variables }}
+    variables: 
+      ${{ insert }}: ${{ parameters.variables }}
 
   steps:
   - checkout: self
@@ -104,4 +105,4 @@ phases:
         PublishLocation: Container
         ArtifactName: AssetManifests
       continueOnError: false
-      condition: and(succeeded(), eq(variables['_DotNetPublishToBlobFeed'], 'true'))
+      condition: and(succeeded(), eq(variables['_DotNetPublishToBlobFeed'], 'true'))