Handle case where volumes in Docker->ACI are null

Fixes #1089

formats/aci.py

@@ -79,12 +79,28 @@ class ACIImage(TarImageFormatter):
 
     return isolators
 
+
+  @staticmethod
+  def _get_docker_config_value(docker_config, key, default_value):
+    # Try the key itself.
+    result = docker_config.get(key)
+    if result is not None:
+      return result or default_value
+
+    # The the lowercase version of the key.
+    result = docker_config.get(key.lower())
+    if result is not None:
+      return result or default_value
+
+    return default_value
+
+
   @staticmethod
   def _build_ports(docker_config):
     """ Builds the ports definitions for the ACI. """
     ports = []
 
-    for docker_port_definition in docker_config.get('ports', docker_config.get('Ports', {})):
+    for docker_port_definition in ACIImage._get_docker_config_value(docker_config, 'Ports', []):
       # Formats:
       # port/tcp
       # port/udp
@@ -119,7 +135,7 @@ class ACIImage(TarImageFormatter):
     def get_name(docker_volume_path):
       return "volume-%s" % docker_volume_path.replace('/', '-')
 
-    for docker_volume_path in docker_config.get('volumes', docker_config.get('Volumes', {})):
+    for docker_volume_path in ACIImage._get_docker_config_value(docker_config, 'Volumes', []):
       if not docker_volume_path:
         continue