Implemented raising error if the attribute is invalid.

moto/ec2/exceptions.py

@@ -332,6 +332,15 @@ class InvalidParameterValueErrorTagNull(EC2ClientError):
             "Tag value cannot be null. Use empty string instead.")
 
 
+class InvalidParameterValueErrorUnknownAttribute(EC2ClientError):
+
+    def __init__(self, parameter_value):
+        super(InvalidParameterValueErrorUnknownAttribute, self).__init__(
+            "InvalidParameterValue",
+            "Value ({0}) for parameter attribute is invalid. Unknown attribute."
+            .format(parameter_value))
+
+
 class InvalidInternetGatewayIdError(EC2ClientError):
 
     def __init__(self, internet_gateway_id):

moto/ec2/models.py

@@ -54,6 +54,7 @@ from .exceptions import (
     InvalidNetworkInterfaceIdError,
     InvalidParameterValueError,
     InvalidParameterValueErrorTagNull,
+    InvalidParameterValueErrorUnknownAttribute,
     InvalidPermissionNotFoundError,
     InvalidPermissionDuplicateError,
     InvalidRouteTableIdError,
@@ -383,6 +384,10 @@ class NetworkInterfaceBackend(object):
 
 
 class Instance(TaggedEC2Resource, BotoInstance):
+    VALID_ATTRIBUTES = {'instanceType', 'kernel', 'ramdisk', 'userData', 'disableApiTermination',
+                        'instanceInitiatedShutdownBehavior', 'rootDeviceName', 'blockDeviceMapping',
+                        'productCodes', 'sourceDestCheck', 'groupSet', 'ebsOptimized', 'sriovNetSupport'}
+
     def __init__(self, ec2_backend, image_id, user_data, security_groups, **kwargs):
         super(Instance, self).__init__()
         self.ec2_backend = ec2_backend
@@ -793,9 +798,14 @@ class InstanceBackend(object):
         setattr(instance, 'security_groups', new_group_list)
         return instance
 
-    def describe_instance_attribute(self, instance_id, key):
-        if key == 'group_set':
+    def describe_instance_attribute(self, instance_id, attribute):
+        if attribute not in Instance.VALID_ATTRIBUTES:
+            raise InvalidParameterValueErrorUnknownAttribute(attribute)
+
+        if attribute == 'groupSet':
             key = 'security_groups'
+        else:
+            key = camelcase_to_underscores(attribute)
         instance = self.get_instance(instance_id)
         value = getattr(instance, key)
         return instance, value

moto/ec2/responses/instances.py

@@ -113,12 +113,11 @@ class InstanceResponse(BaseResponse):
         # TODO this and modify below should raise IncorrectInstanceState if
         # instance not in stopped state
         attribute = self._get_param('Attribute')
-        key = camelcase_to_underscores(attribute)
         instance_id = self._get_param('InstanceId')
         instance, value = self.ec2_backend.describe_instance_attribute(
-            instance_id, key)
+            instance_id, attribute)
 
-        if key == "group_set":
+        if attribute == "groupSet":
             template = self.response_template(
                 EC2_DESCRIBE_INSTANCE_GROUPSET_ATTRIBUTE)
         else: