在AWS Step Functions中使用aws:loop
可以迭代上一步骤的输出。下面是一个示例代码,演示了如何在AWS Step Functions中使用aws:loop
来迭代上一步骤的输出。
{
"Comment": "AWS Step Functions example",
"StartAt": "Iterate",
"States": {
"Iterate": {
"Type": "Task",
"Resource": "arn:aws:states:::lambda:invoke",
"Parameters": {
"FunctionName": "your_lambda_function",
"Payload.$": "$",
"InvocationType": "RequestResponse"
},
"ResultPath": "$.result",
"Next": "CheckStatus"
},
"CheckStatus": {
"Type": "Choice",
"Choices": [
{
"Variable": "$.result.status",
"StringEquals": "IN_PROGRESS",
"Next": "Wait"
},
{
"Variable": "$.result.status",
"StringEquals": "COMPLETED",
"Next": "ProcessResult"
},
{
"Variable": "$.result.status",
"StringEquals": "FAILED",
"Next": "HandleError"
}
]
},
"Wait": {
"Type": "Wait",
"Seconds": 10,
"Next": "Iterate"
},
"ProcessResult": {
"Type": "Pass",
"Result": "$.result",
"ResultPath": "$.previous",
"Next": "Done"
},
"HandleError": {
"Type": "Fail",
"Cause": "Lambda function failed",
"Error": "LambdaError"
},
"Done": {
"Type": "Succeed"
}
}
}
在上面的示例中,Iterate
状态使用aws:loop
来迭代上一步骤的输出。它调用一个Lambda函数,并将上一步骤的输出作为输入。Lambda函数返回一个状态,表示处理的进度。根据返回的状态,流程会进入不同的状态进行处理。
IN_PROGRESS
,则进入Wait
状态,等待一段时间后重新调用Iterate
状态来检查进度。COMPLETED
,则进入ProcessResult
状态,将结果保存到$.previous
中,并进入Done
状态。FAILED
,则进入HandleError
状态,表示Lambda函数执行失败。这个示例展示了如何使用aws:loop
来迭代上一步骤的输出,并根据不同的状态进行处理。