raise error when name is more than 32 when creating target group

moto/elbv2/exceptions.py

@@ -166,3 +166,11 @@ class DuplicatePriorityError(ELBClientError):
         super(DuplicatePriorityError, self).__init__(
             "ValidationError",
             "Priority '%s' was provided multiple times" % invalid_value)
+
+
+class InvalidTargetGroupNameError(ELBClientError):
+
+    def __init__(self, invalid_name):
+        super(InvalidTargetGroupNameError, self).__init__(
+            "ValidationError",
+            "Target group name '%s' cannot be longer than '32' characters" % invalid_name)

moto/elbv2/models.py

@@ -21,7 +21,8 @@ from .exceptions import (
     ActionTargetGroupNotFoundError,
     InvalidDescribeRulesRequest,
     RuleNotFoundError,
-    DuplicatePriorityError
+    DuplicatePriorityError,
+    InvalidTargetGroupNameError
 )
 
 
@@ -264,6 +265,8 @@ class ELBv2Backend(BaseBackend):
         return [rule]
 
     def create_target_group(self, name, **kwargs):
+        if len(name) > 32:
+            raise InvalidTargetGroupNameError(name)
         for target_group in self.target_groups.values():
             if target_group.name == name:
                 raise DuplicateTargetGroupName()

tests/test_elbv2/test_elbv2.py

@@ -327,6 +327,23 @@ def test_create_target_group_and_listeners():
     response = conn.describe_target_groups()
     response.get('TargetGroups').should.have.length_of(0)
 
+    # Fail to create target group with name which length is 33
+    long_name = 'A' * 33
+    with assert_raises(ClientError):
+        conn.create_target_group(
+            Name=long_name,
+            Protocol='HTTP',
+            Port=8080,
+            VpcId=vpc.id,
+            HealthCheckProtocol='HTTP',
+            HealthCheckPort='8080',
+            HealthCheckPath='/',
+            HealthCheckIntervalSeconds=5,
+            HealthCheckTimeoutSeconds=5,
+            HealthyThresholdCount=5,
+            UnhealthyThresholdCount=2,
+            Matcher={'HttpCode': '200'})
+
 
 @mock_elbv2
 @mock_ec2