I have an API gateway route with a Step Function integration.
In this step function, I need the id given by the request.
With a lambda integration I understand how to do it, but in this case I do not find any ressource. Is it possible, and if yes, how ?
Adapt this VTL request mapping template* to add the path parameters to the state machine input.
%STATEMACHINE% with your State Machine's ARN$includeHeaders or $includeQueryString to false.$requestContext to context key-value pairs. Use @@ instead of quotes, as in "{@@user@@:@@$context.identity.user@@}".## Velocity Template used for API Gateway request mapping template
## "@@" is used here as a placeholder for '"' to avoid using escape characters.
#set($includeHeaders = true)
#set($includeQueryString = true)
#set($includePath = true)
#set($requestContext = '')
#set($inputString = '')
#set($allParams = $input.params())
{
"stateMachineArn": "%STATEMACHINE%",
#set($inputString = "$inputString,@@body@@: $input.body")
#if ($includeHeaders)
#set($inputString = "$inputString, @@header@@:{")
#foreach($paramName in $allParams.header.keySet())
#set($inputString = "$inputString @@$paramName@@: @@$util.escapeJavaScript($allParams.header.get($paramName))@@")
#if($foreach.hasNext)
#set($inputString = "$inputString,")
#end
#end
#set($inputString = "$inputString }")
#end
#if ($includeQueryString)
#set($inputString = "$inputString, @@querystring@@:{")
#foreach($paramName in $allParams.querystring.keySet())
#set($inputString = "$inputString @@$paramName@@: @@$util.escapeJavaScript($allParams.querystring.get($paramName))@@")
#if($foreach.hasNext)
#set($inputString = "$inputString,")
#end
#end
#set($inputString = "$inputString }")
#end
#if ($includePath)
#set($inputString = "$inputString, @@path@@:{")
#foreach($paramName in $allParams.path.keySet())
#set($inputString = "$inputString @@$paramName@@: @@$util.escapeJavaScript($allParams.path.get($paramName))@@")
#if($foreach.hasNext)
#set($inputString = "$inputString,")
#end
#end
#set($inputString = "$inputString }")
#end
## Check if the request context should be included as part of the execution input
#if($requestContext && !$requestContext.empty)
#set($inputString = "$inputString,")
#set($inputString = "$inputString @@requestContext@@: $requestContext")
#end
#set($inputString = "$inputString}")
#set($inputString = $inputString.replaceAll("@@",'"'))
#set($len = $inputString.length() - 1)
"input": "{$util.escapeJavaScript($inputString.substring(1,$len))}"
}
* The template is taken from the AWS Cloud Development Kit repo. It is part of the StepFunctionRestApi construct's implementation.
If you're only interested in reading path parameters, here's a compact template you can use.
#set($inputString = "{@requestBody@: $input.json('$'), @pathParameters@: {")
#set($pathParams = $input.params().get('path'))
#foreach($paramName in $pathParams.keySet())
#set($inputString = "$inputString @$paramName@: @$pathParams.get($paramName)@")
#if($foreach.hasNext)
#set($inputString = "$inputString,")
#end
#end
#set($inputString = "$inputString }}")
#set($inputString = $inputString.replaceAll("@",'"'))
{
"input": "$util.escapeJavaScript($inputString).replaceAll("\\'","'")",
"name": "$context.requestId",
"stateMachineArn": "${ErNameIntent}"
}
This will result in a payload like:
{
"requestBody": <requestbody>,
"pathParameters": {
<key1>: <value1>,
<key2>: <value2>,
...
<keyN>: <valueN>
}
}
