Micronaut function support for AWS API Gateway

[drissamri]

Expected Behaviour

Out of the box support for AWS Lambda that are used with an AWS API Gateway in front of it.
This seems like a common use case, which would be nice if this could be supported without having to provide custom code for it.

Maybe several handlers could be provided, like this is done in Spring?
https://github.com/spring-cloud/spring-cloud-function/blob/master/spring-cloud-function-adapters/spring-cloud-function-adapter-aws/src/main/java/org/springframework/cloud/function/adapter/aws/SpringBootApiGatewayRequestHandler.java

Actual Behaviour

No out of the box support

[sdelamo]

I've added a section (API AWS Gateway) to the Functions AWS Lambda Guide

http://guides.micronaut.io/micronaut-function-aws-lambda/guide/index.html#awsApiGateway

[drissamri]

thanks @sdelamo, but usually AWS API Gateway in combination with AWS Lambda is used with Proxy Integration AFAIK (mentioned in the AWS docs), in which it transforms the input and output.

Reference:
The Lambda custom integration, formerly known as the Lambda integration, is a legacy technology. We recommend that you use the Lambda proxy integration for any new API. For more information, see Build an API Gateway API with Lambda Proxy Integration

• https://docs.aws.amazon.com/apigateway/latest/developerguide/set-up-lambda-proxy-integrations.html#api-gateway-simple-proxy-for-lambda-output-format
• https://docs.aws.amazon.com/apigateway/latest/developerguide/set-up-lambda-proxy-integrations.html#api-gateway-simple-proxy-for-lambda-output-format

This is why Spring for example has a specific ApiGatewayRequestHandler which does the necessary mapping (and perhaps more). Something like this would most likely be preferable out of the box for Micronaut as well?

[musketyr]

@drissamri you may find this library useful https://github.com/agorapulse/micronaut-libraries we faced the same issues

[fellmann]

+1 for this. Easy integration with API Gateway would be great, similar to https://github.com/awslabs/aws-serverless-java-container/tree/master/aws-serverless-java-container-spark for Spark.

[djeverson]

+1. This should be treated as a first-class citizen with Micronaut. We've been struggling with a complete POC of Micronaut on AWS Lambda.

[graemerocher]

Probably should be built on https://github.com/awslabs/aws-serverless-java-container/tree/master/aws-serverless-java-container-core

[graemerocher]

API Gateway support added and documented here https://micronaut-projects.github.io/micronaut-aws/snapshot/guide/#apiProxy

Example app can be found at https://github.com/micronaut-projects/micronaut-aws/tree/master/examples/api-proxy-example

[drissamri]

@graemerocher this seems to work with the generated API Gateway URL (e.g: https://fiyxdrgglb.execute-api.eu-west-1.amazonaws.com/dev/label) but doesn't seem to work with a custom domain.

The lambda is invoked but gives back a HTTP 404, should this be logged as a bug or is there something else that needs to be configured? It seems like there was a related bug in the past: aws/serverless-java-container#112

01:23:47 START RequestId: ea035c1f-f0c8-4be3-8a3b-4bcc5c0b9f50 Version: $LATEST
01:23:47 END RequestId: ea035c1f-f0c8-4be3-8a3b-4bcc5c0b9f50
01:23:47 REPORT RequestId: ea035c1f-f0c8-4be3-8a3b-4bcc5c0b9f50	Duration: 8.56 ms	Billed Duration: 100 ms Memory Size: 1024 MB	Max Memory Used: 148 MB

[musketyr]

@graemerocher I dealt with a similar issue. with a custom name, you get everything into the path including stage context. feel free to use my solution

https://github.com/agorapulse/micronaut-libraries/blob/master/micronaut-function-aws-agp/src/main/groovy/com/agorapulse/micronaut/agp/ApiGatewayProxyHttpRequest.java#L203-L212

[djeverson]

support of custom domain is a requirement for us. This item should be re-opened to address.

[drissamri]

I have created a new issue since this does seem to be a bug. If I can help out in any way with testing this since I have a domain setup in AWS, feel free to ping me.

[graemerocher]

PRs are welcome. Otherwise will look into it next week. Thanks