StepFunctionsLocal 不接受 $$ 参数

Question

As documented here , the AWS state machine definition syntax allows access to attributes from the higher scope within a map state iteration with $$.Map.Item.Value :

{
  "StartAt": "ExampleMapState",
  "States": {
    "ExampleMapState": {
      "Type": "Map",
      "Parameters": {
               "ContextValue.$": "$$.Map.Item.Value"
             },
      "Iterator": {
         "StartAt": "TestPass",
         "States": {
           "TestPass": {
             "Type": "Pass",    
             "End": true
           }
         }
      },
      "End": true
    }
  }
} 

However, when run with the StepFunctionsLocal (both Java and Docker versions) this example definition itself raises SCHEMA_VALIDATION_FAILED error:

SCHEMA_VALIDATION_FAILED: The value for the field 'ContextValue.$' must be a valid JSONPath or a valid intrinsic function call at /States/ExampleMapState/Parameters

Am I missing something or is this a bug in the StepFunctionsLocal?

Answer 1

检查您的脚本以确保您已正确转义双 $$

Answer 2

After some tests, my best guess is that it's a bug in the aws cli (or a scaping issue when declaring the sfn definition, as stated here , though I wasn't able to do it).

Anyway, I tried boto3 instead of the cli using this example definition.

>>> definition = """
... {
...   "Comment": "Accessing context object in a state machine",
...   "StartAt": "Get execution context data",
...   "States": {
...     "Get execution context data": {
...       "Type": "Pass",
...       "Parameters": {
...         "startTime.$": "$$.Execution.StartTime",
...         "execName.$": "$$.Execution.Name"
...       },
...       "ResultPath": "$.executionContext",
...       "End": true
...     }
...   }
... }"""
>>> role = "arn:aws:iam::012345678901:role/DummyRole"
>>> r = client.create_state_machine(name="Test", definition=definition, roleArn=role)
>>> pprint.pprint(r)
{'ResponseMetadata': {'HTTPHeaders': {'content-length': '161',
                                      'date': 'Fri, 30 Dec 2022 19:46:31 GMT',
                                      'server': 'Jetty(9.4.43.v20210629)'},
                      'HTTPStatusCode': 200,
                      'RetryAttempts': 0},
 'creationDate': datetime.datetime(2022, 12, 30, 14, 46, 31, 770000, tzinfo=tzlocal()),
 'stateMachineArn': 'arn:aws:states:us-west-2:123456789012:stateMachine:Test'}