AWSLambda - refactor exception handling

moto/awslambda/exceptions.py

@@ -0,0 +1,31 @@
+from botocore.client import ClientError
+
+
+class LambdaClientError(ClientError):
+    def __init__(self, error, message):
+        error_response = {"Error": {"Code": error, "Message": message}}
+        super(LambdaClientError, self).__init__(error_response, None)
+
+
+class CrossAccountNotAllowed(LambdaClientError):
+    def __init__(self):
+        super(CrossAccountNotAllowed, self).__init__(
+            "AccessDeniedException", "Cross-account pass role is not allowed."
+        )
+
+
+class InvalidParameterValueException(LambdaClientError):
+    def __init__(self, message):
+        super(InvalidParameterValueException, self).__init__(
+            "InvalidParameterValueException", message
+        )
+
+
+class InvalidRoleFormat(LambdaClientError):
+    pattern = r"arn:(aws[a-zA-Z-]*)?:iam::(\d{12}):role/?[a-zA-Z_0-9+=,.@\-_/]+"
+
+    def __init__(self, role):
+        message = "1 validation error detected: Value '{0}' at 'role' failed to satisfy constraint: Member must satisfy regular expression pattern: {1}".format(
+            role, InvalidRoleFormat.pattern
+        )
+        super(InvalidRoleFormat, self).__init__("ValidationException", message)

moto/awslambda/models.py

@@ -33,6 +33,11 @@ from moto.s3.models import s3_backend
 from moto.logs.models import logs_backends
 from moto.s3.exceptions import MissingBucket, MissingKey
 from moto import settings
+from .exceptions import (
+    CrossAccountNotAllowed,
+    InvalidRoleFormat,
+    InvalidParameterValueException,
+)
 from .utils import make_function_arn, make_function_ver_arn
 from moto.sqs import sqs_backends
 from moto.dynamodb2 import dynamodb_backends2
@@ -215,9 +220,8 @@ class LambdaFunction(BaseModel):
                 key = s3_backend.get_key(self.code["S3Bucket"], self.code["S3Key"])
             except MissingBucket:
                 if do_validate_s3():
-                    raise ValueError(
+                    raise InvalidParameterValueException(
-                        "InvalidParameterValueException",
+                        "Error occurred while GetObject. S3 Error Code: NoSuchBucket. S3 Error Message: The specified bucket does not exist"
-                        "Error occurred while GetObject. S3 Error Code: NoSuchBucket. S3 Error Message: The specified bucket does not exist",
                     )
             except MissingKey:
                 if do_validate_s3():
@@ -669,28 +673,19 @@ class LambdaStorage(object):
         :param fn: Function
         :type fn: LambdaFunction
         """
-        pattern = r"arn:(aws[a-zA-Z-]*)?:iam::(\d{12}):role/?[a-zA-Z_0-9+=,.@\-_/]+"
+        valid_role = re.match(InvalidRoleFormat.pattern, fn.role)
-        valid_role = re.match(pattern, fn.role)
         if valid_role:
             account = valid_role.group(2)
             if account != ACCOUNT_ID:
-                raise ValueError(
+                raise CrossAccountNotAllowed()
-                    "AccessDeniedException", "Cross-account pass role is not allowed."
-                )
             try:
                 iam_backend.get_role_by_arn(fn.role)
             except IAMNotFoundException:
-                raise ValueError(
+                raise InvalidParameterValueException(
-                    "InvalidParameterValueException",
+                    "The role defined for the function cannot be assumed by Lambda."
-                    "The role defined for the function cannot be assumed by Lambda.",
                 )
         else:
-            raise ValueError(
+            raise InvalidRoleFormat(fn.role)
-                "ValidationException",
-                "1 validation error detected: Value '{0}' at 'role' failed to satisfy constraint: Member must satisfy regular expression pattern: {1}".format(
-                    fn.role, pattern
-                ),
-            )
         if fn.function_name in self._functions:
             self._functions[fn.function_name]["latest"] = fn
         else:

moto/awslambda/responses.py

@@ -211,26 +211,14 @@ class LambdaResponse(BaseResponse):
         return 200, {}, json.dumps(result)
 
     def _create_function(self, request, full_url, headers):
-        try:
+        fn = self.lambda_backend.create_function(self.json_body)
-            fn = self.lambda_backend.create_function(self.json_body)
+        config = fn.get_configuration()
-        except ValueError as e:
+        return 201, {}, json.dumps(config)
-            return 400, {}, json.dumps({"__type": e.args[0], "message": e.args[1]})
-        else:
-            config = fn.get_configuration()
-            return 201, {}, json.dumps(config)
 
     def _create_event_source_mapping(self, request, full_url, headers):
-        try:
+        fn = self.lambda_backend.create_event_source_mapping(self.json_body)
-            fn = self.lambda_backend.create_event_source_mapping(self.json_body)
+        config = fn.get_configuration()
-        except ValueError as e:
+        return 201, {}, json.dumps(config)
-            return (
-                400,
-                {},
-                json.dumps({"Error": {"Code": e.args[0], "Message": e.args[1]}}),
-            )
-        else:
-            config = fn.get_configuration()
-            return 201, {}, json.dumps(config)
 
     def _list_event_source_mappings(self, event_source_arn, function_name):
         esms = self.lambda_backend.list_event_source_mappings(

tests/test_cloudformation/test_cloudformation_stack_crud.py

@@ -4,6 +4,7 @@ import os
 import json
 
 import boto
+import boto3
 import boto.iam
 import boto.s3
 import boto.s3.key
@@ -19,9 +20,9 @@ from moto import (
     mock_cloudformation_deprecated,
     mock_s3_deprecated,
     mock_route53_deprecated,
+    mock_iam,
 )
 from moto.cloudformation import cloudformation_backends
-from moto.iam import mock_iam_deprecated
 
 dummy_template = {
     "AWSTemplateFormatVersion": "2010-09-09",
@@ -596,9 +597,8 @@ def test_create_stack_kinesis():
 
 
 def get_role_name():
-    with mock_iam_deprecated():
+    with mock_iam():
-        iam = boto.connect_iam()
+        iam = boto3.client("iam")
-        role = iam.create_role("my-role")["create_role_response"]["create_role_result"][
+        return iam.create_role(
-            "role"
+            RoleName="TestRole", AssumeRolePolicyDocument="some_policy"
-        ]["arn"]
+        )["Role"]["Arn"]
-        return role