来自内部 Step Function 的过滤结果

Question

我有一个启动另一个 Step Function 的 Step Function。

内步函数的输出没问题，正是我想要的

这里是触发外步函数的代码：

{
  "StartAt": "MySF",
  "States": {
    "Textract": {
      "Type": "Task",
      "OutputPath": "$",
      "Resource": "arn:aws:states:::states:startExecution.sync:2",
      "Parameters": {
        "Input": {
          "input.$": "$$.Execution.Input"
        },
        "StateMachineArn": "inner_step_function_arn"
      },
      "End": true
    }
  },
  "TimeoutSeconds": 3600
}

如果我查看外步函数，内步函数的结果比我需要的多得多，它基本上是该次执行的元数据，如下所示：

{
  "ExecutionArn": "inner_step_function_arn"
  "Input": {
    "input": {
        the output that I need
    }
  },
  "InputDetails": {
    "Included": true
  },
  "Name": "xxx",
  "Output": {
    the output that I need
  },
  "OutputDetails": {
    "Included": true
  },
  "StartDate": 1637923353831,
  "StateMachineArn": "inner_step_function_arn,
  "Status": "SUCCEEDED",
  "StopDate": 1637923386955
}

所以我的问题是如何只得到 "input" 节点内的结果。有没有办法只过滤输入？

谢谢。

Answer 1

您可以使用ResultSelector仅从外步函数中过滤出所需的结果。它允许选择您需要的字段。您的 SF 定义应如下所示：

{
  "StartAt": "MySF",
  "States": {
    "Textract": {
      "Type": "Task",
      "OutputPath": "$",
      "Resource": "arn:aws:states:::states:startExecution.sync:2",
      "Parameters": {
        "Input": {
          "input.$": "$$.Execution.Input"
        },
        "StateMachineArn": "inner_step_function_arn"
      },
      "ResultSelector": {
        "Output.$": "$.Output"
      },
      "End": true
    }
  },
  "TimeoutSeconds": 3600
}

来自内部 Step Function 的过滤结果

Filter result from inner Step Function

aws-step-functions