From a727194742dd7b28c265527f71e2a3669b71516a Mon Sep 17 00:00:00 2001
From: eric sciple <ericsciple@users.noreply.github.com>
Date: Sun, 12 Jan 2020 23:02:36 -0500
Subject: [PATCH] allow container to be null/empty (#266)

---
 .../PipelineTemplateConverter.cs                 |  5 +++++
 src/Sdk/DTPipelines/workflow-v1.0.json           | 16 ++++++++++++++--
 2 files changed, 19 insertions(+), 2 deletions(-)

diff --git a/src/Sdk/DTPipelines/Pipelines/ObjectTemplating/PipelineTemplateConverter.cs b/src/Sdk/DTPipelines/Pipelines/ObjectTemplating/PipelineTemplateConverter.cs
index e76c08aa6..951d0869f 100644
--- a/src/Sdk/DTPipelines/Pipelines/ObjectTemplating/PipelineTemplateConverter.cs
+++ b/src/Sdk/DTPipelines/Pipelines/ObjectTemplating/PipelineTemplateConverter.cs
@@ -154,6 +154,11 @@ namespace GitHub.DistributedTask.Pipelines.ObjectTemplating
 
             if (value is StringToken containerLiteral)
             {
+                if (String.IsNullOrEmpty(containerLiteral.Value))
+                {
+                    return null;
+                }
+
                 result.Image = containerLiteral.Value;
             }
             else
diff --git a/src/Sdk/DTPipelines/workflow-v1.0.json b/src/Sdk/DTPipelines/workflow-v1.0.json
index 02741c871..21e6d2b63 100644
--- a/src/Sdk/DTPipelines/workflow-v1.0.json
+++ b/src/Sdk/DTPipelines/workflow-v1.0.json
@@ -472,7 +472,7 @@
         "matrix"
       ],
       "one-of": [
-        "non-empty-string",
+        "string",
         "container-mapping"
       ]
     },
@@ -497,10 +497,22 @@
       ],
       "mapping": {
         "loose-key-type": "non-empty-string",
-        "loose-value-type": "container"
+        "loose-value-type": "services-container"
       }
     },
 
+    "services-container": {
+      "context": [
+        "github",
+        "strategy",
+        "matrix"
+      ],
+      "one-of": [
+        "non-empty-string",
+        "container-mapping"
+      ]
+    },
+
     "container-env": {
       "mapping": {
         "loose-key-type": "non-empty-string",