Rails Web Development with AWS Lambda

I talked about how to develop rails web application on AWS Lambda. Slides for M3 Tech Talk #224.

Transcript

1. Rails Web Development
   with AWS Lambda
   2023/07/07 M3 Tech Talk #224 @ma2ge
   

   View Slide

2. self-introduction
   • ma2ge@Twitter, Threads
   !"
   • ma2gedev@GitHub
   • Team SRE
   • 10+ years working at M3
   ! "
   

   View Slide

3. Various serverless services
   running your web app on AWS
   • Fargate
   • App Runner
   • Lambda <- Today's target
   • Used in combination with API Gateway in our project
   

   View Slide

4. Problems to develop code on
   Lambda
   • Vendor Lock-in
   • Complexity is getting higher
   • The code is scattered and lacks readability if there are
   many functions
   • Need to know more than web app knowledges
   • such as Runtime Interface Client, Serverless Framework,
   SAM and etc...
   

   View Slide

5. Ideally, I would like to ...
   • Minimize vendor lock-in
   • Prioritize organized and readable code
   • Continue using our Rails development skills
   

   View Slide

6. AWS Lambda Web
   Adapter
   https://github.com/awslabs/aws-lambda-web-adapter
   

   View Slide

7. Supports any web
   frameworks and
   languages, no new code
   dependency to include
   — Referenced from: AWS Lambda Web Adapter's
   README.md
   

   View Slide

8. How AWS Lambda Web Adapter
   works
   • Lambda Extensions API
   Image source: https://docs.aws.amazon.com/lambda/latest/dg/runtimes-extensions-
   api.html
   

   View Slide

9. Image source: https://docs.aws.amazon.com/lambda/latest/dg/runtimes-extensions-
   api.html
   

   View Slide

10. Image source: https://github.com/awslabs/aws-lambda-web-adapter/blob/main/
    README.md
    

    View Slide

11. ɹ
    

    View Slide

12. Just tried it!
    # Add the following into your Dockerfile
    COPY --from=public.ecr.aws/awsguru/aws-lambda-adapter:0.7.0 /lambda-adapter /opt/extensions/lambda-adapter
    

    View Slide

13. It worked!
    

    View Slide

14. Advantages
    • Can focus on Rails development
    • Mitigate cold start with API Gateway's Lambda Proxy
    Integration
    

    View Slide

15. However ...
    • Cold start: Rails is not fast & the extension brings extra costs
    • Are there any servers optimized for a single process?
    • There are many servers that run on multiple processes/
    threads, but I'm not sure about a server suitable for a
    single process?
    • Single Dockerfile (this is a minor issue)
    • Same Dockerfile can't be used for job processes because
    the extension always starts up and handles events
    

    View Slide

16. Lamby
    https://github.com/rails-lambda/lamby
    

    View Slide

17. Lamby
    • An approach similar to AWS Lambda Web Adapter
    • Additionally, it operates without an extra process
    

    View Slide

18. How Lamby works
    Lamby is an AWS Lambda Web Adapter for Rack applications.
    — Referenced from: Lamby's README.md
    • Rack server converts Lambda events into Rack requests, and
    vice versa
    • So your rails app code and development style are not
    affected
    

    View Slide

19. It solves the problems
    • Remove extra cost on cold starts with Lambda Web Adapter
    • No need to bother finding a suitable server for single
    process; instead, Lamby starts the Rails app
    • Can use Single Dockerfile by overriding CMD
    

    View Slide

20. Some problems encountered
    when using Lamby
    • Lamby passes URL queries percent-decoded
    • We solve this with a monkey patch in our project
    • Cold start times are long
    • Following the documentation: enable Bootsnap and
    create cache during Docker build phase
    • AWS Lambda Ruby RIC does not currently support Ruby 3.x
    

    View Slide

21. Summary
    • Approaches to Rails Web Development on Lambda
    • AWS Lambda Web Adapter
    • Lamby
    • Continue to use rails development skills
    • Code remains well-organized and keeps readability
    • Mitigate vendor lock-in
    

    View Slide

22. Resources: Lambda x Rails
    • Ruby on Rails on Lambda - Speaker Deck https://
    speakerdeck.com/joker1007/ruby-on-rails-on-lambda
    

    View Slide

23. Resources: Lambda Web Adapter
    • GitHub - awslabs/aws-lambda-web-adapter: Run web
    applications on AWS Lambda https://github.com/awslabs/
    aws-lambda-web-adapter
    • Lambda Extensions API - AWS Lambda https://
    docs.aws.amazon.com/lambda/latest/dg/runtimes-
    extensions-api.html
    

    View Slide

24. Resources: Lamby
    • GitHub - rails-lambda/lamby: Simple Rails & AWS
    Lambda Integration https://github.com/rails-lambda/lamby
    • GitHub - rack/rack: A modular Ruby web server interface.
    https://github.com/rack/rack
    

    View Slide

25. END
    

    View Slide