Break an map loop execution in AWS step functions - amazon-web-services

Question

I'm trying to build a step function with a loop (Map) inside that can be stopped whenever a specefic Error is thrown, something like this
"Job": {
"Type": "Map",
"InputPath": "$.content",
"ItemsPath": "$.data",
"MaxConcurrency": 0,
"Iterator": {
"StartAt": "Validate",
"States": {
"Validate": {
"Type": "Task",
"Resource": "arn:aws:lambda:us-east-1:123456789012:function:ship-val",
"Catch": [
{
"ErrorEquals": [
"ErrorOne"
],
"Next": "BreakLoop"
},
{
"ErrorEquals": ["States.ALL"],
"Next": "FailUncaughtError"
}
],
},
"FailUncaughtError":{
"Type": "Fail",
"Error": "Uncaught error"
},
"BreakLoop":{
"Type": "Fail",
"Error": "the loop should be stopped"
}
}
},
"ResultPath": "$.content.data",
"End": true
}
I tried to make the Next element of the Catch to a state outside the Map but I couldn't because the Map accept only states within it. Moreover, AFAIK there is no mention for a feature like this in AWS docs

Answer 1

Instead of catching the error inside the Map state, don't catch it and let the Map state to fail.
And add a catch to Map state and if the error is equal to what you are looking for continue to the next step:
{
"StartAt": "Map",
"States": {
"Map": {
"Type": "Map",
"ItemsPath": "$.array",
"Iterator": {
"StartAt": "FaultyLambda",
"States": {
"FaultyLambda": {
"Type": "Task",
"Resource": "arn:aws:states:::lambda:invoke",
"Parameters": {
"FunctionName": "your function arn",
"Payload": {
"a": 1
}
},
"End": true
}
}
},
"Catch": [
{
"ErrorEquals": ["ErrorOne"],
"Next": "BreakLoop"
}
],
"Next": "BreakLoop"
},
"BreakLoop": {
"Type": "Pass",
"End": true
}
}
}
Any other error will not be catched and failed your entire execution.