我有一个用例，其中用户定义了一个工作流。当用户点击 API 时，step 函数就会启动。 lambda 返回基于用户的步骤列表并启动工作流，例如：
步骤1。它处理（提取）文档，
第2步。插入一些数据到
D B
第三步。 .....
第4步。 .....
这里的步骤在地图中，因为这些步骤是从 lambda 返回的。 有没有什么方法可以从每个地图迭代中获得响应，以便我可以向用户展示流程在哪一步，以及上一步的输出。
测试获取输入工作流：返回一个数组：[step1, step2, ....]
工作流步骤-lambda：根据步骤名称调用一些 lambda
【问题讨论】：
标签： aws-api-gateway aws-step-functions aws-event-bridge
假设您使用的是标准工作流，您可以使用 GetExecutionHistory API 操作获取此信息：https://docs.aws.amazon.com/step-functions/latest/apireference/API_GetExecutionHistory.html
您需要查找 MapIterationSucceeded 类型的事件，获取 previousEventId，然后在 HistoryEvent 中查找具有该 ID 的输出。
例如，如果您有这样的状态机：
{
"StartAt": "Generate Array for Map",
"States": {
"Generate Array for Map": {
"Type": "Pass",
"Next": "Map",
"Result": [
1,
2,
3,
4,
5
]
},
"Map": {
"Type": "Map",
"ItemProcessor": {
"ProcessorConfig": {
"Mode": "INLINE"
},
"StartAt": "Generate Random Number",
"States": {
"Generate Random Number": {
"Type": "Pass",
"End": true,
"Parameters": {
"Random Number.$": "States.MathRandom(1,1000)"
}
}
}
},
"End": true
}
}
}
您的执行历史将如下所示：
{
"events": [
{
"timestamp": "2022-12-08T16:44:07.651000-08:00",
"type": "ExecutionStarted",
"id": 1,
"previousEventId": 0,
"executionStartedEventDetails": {
"input": "{
"Comment": "Insert your JSON here"
}",
"inputDetails": {
"truncated": false
},
"roleArn": "arn:aws:iam::000000000000:role/service-role/StepFunctions-MapTest-role-613230dd"
}
},
{
"timestamp": "2022-12-08T16:44:07.698000-08:00",
"type": "PassStateEntered",
"id": 2,
"previousEventId": 0,
"stateEnteredEventDetails": {
"name": "Generate Array for Map",
"input": "{
"Comment": "Insert your JSON here"
}",
"inputDetails": {
"truncated": false
}
}
},
{
"timestamp": "2022-12-08T16:44:07.698000-08:00",
"type": "PassStateExited",
"id": 3,
"previousEventId": 2,
"stateExitedEventDetails": {
"name": "Generate Array for Map",
"output": "[1,2,3,4,5]",
"outputDetails": {
"truncated": false
}
}
},
{
"timestamp": "2022-12-08T16:44:07.698000-08:00",
"type": "MapStateEntered",
"id": 4,
"previousEventId": 3,
"stateEnteredEventDetails": {
"name": "Map",
"input": "[1,2,3,4,5]",
"inputDetails": {
"truncated": false
}
}
},
{
"timestamp": "2022-12-08T16:44:07.698000-08:00",
"type": "MapStateStarted",
"id": 5,
"previousEventId": 4,
"mapStateStartedEventDetails": {
"length": 5
}
},
{
"timestamp": "2022-12-08T16:44:07.698000-08:00",
"type": "MapIterationStarted",
"id": 6,
"previousEventId": 5,
"mapIterationStartedEventDetails": {
"name": "Map",
"index": 0
}
},
{
"timestamp": "2022-12-08T16:44:07.698000-08:00",
"type": "MapIterationStarted",
"id": 7,
"previousEventId": 5,
"mapIterationStartedEventDetails": {
"name": "Map",
"index": 1
}
},
{
"timestamp": "2022-12-08T16:44:07.698000-08:00",
"type": "MapIterationStarted",
"id": 8,
"previousEventId": 5,
"mapIterationStartedEventDetails": {
"name": "Map",
"index": 2
}
},
{
"timestamp": "2022-12-08T16:44:07.698000-08:00",
"type": "MapIterationStarted",
"id": 9,
"previousEventId": 5,
"mapIterationStartedEventDetails": {
"name": "Map",
"index": 3
}
},
{
"timestamp": "2022-12-08T16:44:07.698000-08:00",
"type": "MapIterationStarted",
"id": 10,
"previousEventId": 5,
"mapIterationStartedEventDetails": {
"name": "Map",
"index": 4
}
},
{
"timestamp": "2022-12-08T16:44:07.698000-08:00",
"type": "PassStateEntered",
"id": 11,
"previousEventId": 6,
"stateEnteredEventDetails": {
"name": "Generate Random Number",
"input": "1",
"inputDetails": {
"truncated": false
}
}
},
{
"timestamp": "2022-12-08T16:44:07.698000-08:00",
"type": "PassStateExited",
"id": 12,
"previousEventId": 11,
"stateExitedEventDetails": {
"name": "Generate Random Number",
"output": "{"Random Number":259}",
"outputDetails": {
"truncated": false
}
}
},
{
"timestamp": "2022-12-08T16:44:07.698000-08:00",
"type": "MapIterationSucceeded",
"id": 13,
"previousEventId": 12,
"mapIterationSucceededEventDetails": {
"name": "Map",
"index": 0
}
},
{
"timestamp": "2022-12-08T16:44:07.698000-08:00",
"type": "PassStateEntered",
"id": 14,
"previousEventId": 7,
"stateEnteredEventDetails": {
"name": "Generate Random Number",
"input": "2",
"inputDetails": {
"truncated": false
}
}
},
{
"timestamp": "2022-12-08T16:44:07.698000-08:00",
"type": "PassStateExited",
"id": 15,
"previousEventId": 14,
"stateExitedEventDetails": {
"name": "Generate Random Number",
"output": "{"Random Number":776}",
"outputDetails": {
"truncated": false
}
}
},
{
"timestamp": "2022-12-08T16:44:07.698000-08:00",
"type": "MapIterationSucceeded",
"id": 16,
"previousEventId": 15,
"mapIterationSucceededEventDetails": {
"name": "Map",
"index": 1
}
},
{
"timestamp": "2022-12-08T16:44:07.698000-08:00",
"type": "PassStateEntered",
"id": 17,
"previousEventId": 8,
"stateEnteredEventDetails": {
"name": "Generate Random Number",
"input": "3",
"inputDetails": {
"truncated": false
}
}
},
{
"timestamp": "2022-12-08T16:44:07.698000-08:00",
"type": "PassStateExited",
"id": 18,
"previousEventId": 17,
"stateExitedEventDetails": {
"name": "Generate Random Number",
"output": "{"Random Number":743}",
"outputDetails": {
"truncated": false
}
}
},
{
"timestamp": "2022-12-08T16:44:07.698000-08:00",
"type": "MapIterationSucceeded",
"id": 19,
"previousEventId": 18,
"mapIterationSucceededEventDetails": {
"name": "Map",
"index": 2
}
},
{
"timestamp": "2022-12-08T16:44:07.698000-08:00",
"type": "PassStateEntered",
"id": 20,
"previousEventId": 9,
"stateEnteredEventDetails": {
"name": "Generate Random Number",
"input": "4",
"inputDetails": {
"truncated": false
}
}
},
{
"timestamp": "2022-12-08T16:44:07.698000-08:00",
"type": "PassStateExited",
"id": 21,
"previousEventId": 20,
"stateExitedEventDetails": {
"name": "Generate Random Number",
"output": "{"Random Number":790}",
"outputDetails": {
"truncated": false
}
}
},
{
"timestamp": "2022-12-08T16:44:07.698000-08:00",
"type": "MapIterationSucceeded",
"id": 22,
"previousEventId": 21,
"mapIterationSucceededEventDetails": {
"name": "Map",
"index": 3
}
},
{
"timestamp": "2022-12-08T16:44:07.698000-08:00",
"type": "PassStateEntered",
"id": 23,
"previousEventId": 10,
"stateEnteredEventDetails": {
"name": "Generate Random Number",
"input": "5",
"inputDetails": {
"truncated": false
}
}
},
{
"timestamp": "2022-12-08T16:44:07.698000-08:00",
"type": "PassStateExited",
"id": 24,
"previousEventId": 23,
"stateExitedEventDetails": {
"name": "Generate Random Number",
"output": "{"Random Number":632}",
"outputDetails": {
"truncated": false
}
}
},
{
"timestamp": "2022-12-08T16:44:07.698000-08:00",
"type": "MapIterationSucceeded",
"id": 25,
"previousEventId": 24,
"mapIterationSucceededEventDetails": {
"name": "Map",
"index": 4
}
},
{
"timestamp": "2022-12-08T16:44:07.698000-08:00",
"type": "MapStateSucceeded",
"id": 26,
"previousEventId": 25
},
{
"timestamp": "2022-12-08T16:44:07.698000-08:00",
"type": "MapStateExited",
"id": 27,
"previousEventId": 25,
"stateExitedEventDetails": {
"name": "Map",
"output": "[{"Random Number":259},{"Random Number":776},{"Random Number":743},{"Random Number":790},{"Random Number":632}]",
"outputDetails": {
"truncated": false
}
}
},
{
"timestamp": "2022-12-08T16:44:07.745000-08:00",
"type": "ExecutionSucceeded",
"id": 28,
"previousEventId": 27,
"executionSucceededEventDetails": {
"output": "[{"Random Number":259},{"Random Number":776},{"Random Number":743},{"Random Number":790},{"Random Number":632}]",
"outputDetails": {
"truncated": false
}
}
}
]
}
【讨论】：