Invalid type for parameter cluster

[nicholasvmoore]

Parameter validation failed:
Invalid type for parameter cluster, value: None, type: <type 'NoneType'>, valid types: <type 'basestring'>: ParamValidationError
Traceback (most recent call last):
File "/var/task/index.py", line 141, in lambda_handler
clusterListResp = ecsClient.list_container_instances(cluster=clusterName)
File "/var/task/botocore/client.py", line 253, in _api_call
return self._make_api_call(operation_name, kwargs)
File "/var/task/botocore/client.py", line 517, in _make_api_call
api_params, operation_model, context=request_context)
File "/var/task/botocore/client.py", line 572, in _convert_to_request_dict
api_params, operation_model)
File "/var/task/botocore/validate.py", line 270, in serialize_to_request
raise ParamValidationError(report=report.generate_report())
ParamValidationError: Parameter validation failed:
Invalid type for parameter cluster, value: None, type: <type 'NoneType'>, valid types: <type 'basestring'>