Add support for EMR AutoScalingRole (#4630)

moto/emr/models.py

@@ -167,6 +167,7 @@ class FakeCluster(BaseModel):
         step_concurrency_level=1,
         security_configuration=None,
         kerberos_attributes=None,
+        auto_scaling_role=None,
     ):
         self.id = cluster_id or random_cluster_id()
         emr_backend.clusters[self.id] = self
@@ -274,6 +275,7 @@ class FakeCluster(BaseModel):
             security_configuration  # ToDo: Raise if doesn't already exist.
         )
         self.kerberos_attributes = kerberos_attributes
+        self.auto_scaling_role = auto_scaling_role
 
     @property
     def arn(self):

moto/emr/responses.py

@@ -276,6 +276,7 @@ class ElasticMapReduceResponse(BaseResponse):
             log_uri=self._get_param("LogUri"),
             job_flow_role=self._get_param("JobFlowRole"),
             service_role=self._get_param("ServiceRole"),
+            auto_scaling_role=self._get_param("AutoScalingRole"),
             steps=steps_from_query_string(self._get_list_prefix("Steps.member")),
             visible_to_all_users=self._get_bool_param("VisibleToAllUsers", False),
             instance_attrs=instance_attrs,
@@ -652,6 +653,7 @@ DESCRIBE_CLUSTER_TEMPLATE = """<DescribeClusterResponse xmlns="http://elasticmap
       <SecurityConfiguration>{{ cluster.security_configuration }}</SecurityConfiguration>
       {% endif %}
       <ServiceRole>{{ cluster.service_role }}</ServiceRole>
+      <AutoScalingRole>{{ cluster.auto_scaling_role }}</AutoScalingRole>
       <Status>
         <State>{{ cluster.state }}</State>
         <StateChangeReason>

tests/test_emr/test_emr_boto3.py

@@ -116,6 +116,7 @@ def test_describe_cluster():
     }
     args["Tags"] = [{"Key": "tag1", "Value": "val1"}, {"Key": "tag2", "Value": "val2"}]
     args["SecurityConfiguration"] = "my-security-configuration"
+    args["AutoScalingRole"] = "EMR_AutoScaling_DefaultRole"
 
     cluster_id = client.run_job_flow(**args)["JobFlowId"]
 
@@ -164,6 +165,7 @@ def test_describe_cluster():
     cl["SecurityConfiguration"].should.be.a(str)
     cl["SecurityConfiguration"].should.equal(args["SecurityConfiguration"])
     cl["ServiceRole"].should.equal(args["ServiceRole"])
+    cl["AutoScalingRole"].should.equal(args["AutoScalingRole"])
 
     status = cl["Status"]
     status["State"].should.equal("TERMINATED")