python - 使用 boto3 ECS 获取 "Creation of service was not idempotent"。为什么？

Question

我正在像这样调用 ecs.create_service:

createServiceResponse = ecs.create_service(
clientToken='abc123',
cluster=options.cluster,
serviceName=options.service,
desiredCount=1,
taskDefinition='relay:' + str(revision),
role='ecsServiceRole',
loadBalancers=[
    {
        'loadBalancerName': options.elb,
        'containerName': 'relay',
        'containerPort': 8080
    }
]
)

请注意，目前 clientToken 中的值是 abc123，但我已经尝试了各种不同的字符串。该文档说我需要提供它以确保幂等性(http://boto3.readthedocs.org/en/latest/reference/services/ecs.html)但是我不断收到此错误:

Traceback (most recent call last):
  File "./deploy.py", line 103, in <module>
    'containerPort': 8080
  File "/usr/local/lib/python2.7/site-packages/botocore/client.py", line 301, in _api_call
  return self._make_api_call(operation_name, kwargs)
  File "/usr/local/lib/python2.7/site-packages/botocore/client.py", line 386, in _make_api_call
   raise ClientError(parsed_response, operation_name)
botocore.exceptions.ClientError: An error occurred     (InvalidParameterException) when calling the CreateService operation: Creation of service was not idempotent.

为什么？

Answer 1

我想通了。

这是因为我在现有服务上调用 create_service。我应该按如下方式调用 update_service:

ecs.update_service(

cluster=options.cluster,
service=options.service,
taskDefinition='relay:' + str(revision),    
desiredCount=1)