raise BuildFormationError on build or delete

Author: Matthew Fisher

api/exceptions.py

@@ -20,3 +20,17 @@ class BuildNodeError(APIException):
 
     def __init__(self, detail=None):
         self.detail = detail
+
+
+class BuildFormationError(APIException):
+    """
+    Indicates a problem in creating a formation.
+
+    This exception is subclassed from rest_framework's APIException so it
+    isn't reported as "500 SERVER ERROR."
+    """
+
+    status_code = status.HTTP_400_BAD_REQUEST
+
+    def __init__(self, detail=None):
+        self.detail = detail

api/views.py

@@ -24,6 +24,7 @@
 from rest_framework.response import Response
 
 from api import docker, models, serializers
+from .exceptions import BuildFormationError
 
 from deis import settings
 
@@ -318,11 +319,17 @@ def create(self, request, **kwargs):
 
     def post_save(self, layer, created=False, **kwargs):
         if created:
-            layer.build()
+            try:
+                layer.build()
+            except EnvironmentError as err:
+                raise BuildFormationError(str(err))
 
     def destroy(self, request, **kwargs):
         layer = self.get_object()
-        layer.destroy()
+        try:
+            layer.destroy()
+        except EnvironmentError as err:
+            raise BuildFormationError(str(err))
         return Response(status=status.HTTP_204_NO_CONTENT)