Presented at ServerlessConf NYC 2016. Seven lessons learned, experiences made and problems solved while getting the most out of Clojure and AWS Lambda.

1. Serverless Adventures
with AWS Lambda and
Clojure

2. ________ ______
__ ___/______________ ________________ /___________________
_____ _ _ _ ___/_ | / / _ _ ___/_ /_ _ _ ___/_ ___/
____/ // __/ / __ |/ // __/ / _ / / __/(__ )_(__ )
/____/ ___//_/ _____/ ___//_/ /_/ ___//____/ /____/
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88~~~88 88 88 `8b d8' 88~~~~~ 88 V8o88 88 88 88 88`8b 88~~~~~ `Y8b. Y8 I8I 88 88 88 88~~~88
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YP YP Y8888D' YP Y88888P VP V8P YP ~Y8888P' 88 YD Y88888P `8888Y' `8b8' `8d8' Y888888P YP YP YP
┌───────────────────────────────────────────────────────────────────────────────────────────────────────────────────────┐
│ │
│ │
│ ___ ____ __ ____ _______. __ ___ .___ ___. .______ _______ ___ │
│ / / / / / | | | / | / | | _ | / │
│ / ^ / / / | (----` | | / ^ | / | | |_) | | .--. | / ^ │
│ / /_ / | | / /_ | |/| | | _ < | | | | / /_ │
│ / _____ / / .----) | | `----./ _____ | | | | | |_) | | '--' | / _____ │
│ /__/ __ &&&&&&&&&&/ |_______/ |_______/__/ __ |__| |__| |______/ |_______/ /__/ __ │
│ &::::::::::& │
│ &::::&&&:::::& ╔════════════════════════════════════════════════════════════════════════════════╗ │
└────────────────&::::&───&::::&────╣ ╠──┘
&::::& &::::& ║ ║
&::::&&&::::& ║ ______ __ ______ __ __ __ .______ _______ ║
&::::::::::& ║ / || | / __ | | | | | | | _ | ____| ║
&:::::::&& ║ | ,----'| | | | | | | | | | | | | |_) | | |__ ║
&::::::::& &&&& ║ | | | | | | | | .--. | | | | | | | / | __| ║
&:::::&&::& &:::& ║ | `----.| `----.| `--' | | `--' | | `--' | | | ----.| |____ ║
&:::::& &::&&:::&& ║ ______||_______| ______/ ______/ ______/ | _| `._____||_______| ║
&:::::& &:::::& ║ ║
&:::::& &::::& ║ ║
&::::::&&&&::::::&& ╚════════════════════════════════════════════════════════════════════════════════╝
&&::::::::&&&::::&
&&&&&&&& &&&&&

3. Lars Trieloff
!❤
! @trieloff
!" @trieloff

4. !"
!"#$%&'

5. !

6. What?

7. Excel + HTTP = Excelsior

8. !"
github.com/trieloff/excelsior

9. !

10. Why?

11. ! Clojure

12. λ !

13. ! 12 ✕
12factor.net

14. ! Swagger
swagger.io

15. !"?

16. AWS Lambda!

17. !" = #

18. !" = #

19. !"

20. AWS λ + Clojure λ = ♥

21. !

22. Sounds good.

23. Sounds too good.

24. Sounds too good to be true.

25. If something sounds too
good to be true, it
probably is.

26. ┌─────────────┐
│ │
│ │
│ Clojure │
│ ┌─────┼───────┐
│ │ ! │ │
└───────┼─────┘ │
│ AWS Lambda │
│ │
│ │
└─────────────┘

27. !

28. How?

29. → ! github.com/metosin/compojure-api
→ " github.com/jpb/ring-aws-lambda-adapter
→ # github.com/mjul/docjure
→ ⭕ circleci.com
→ % github.com/mhjort/lein-clj-lambda

30. ┌────────────────────────┐ ┌────────────────────────┐
│ ┌────────────────────┐ │ │ │
│ │ ┌────────────────┐ │ │ │ │
│ │ │ ┌────────────┐ │ │ │ │ │
│ │ │ │ Docjure !│ │ │ │ │ │
│ │ │ └────────────┘ │ │ │ ┌────────────┐ │ AWS API Gateway │
│ │ │ My code " │ │ │ ┌────────▶│swagger.json│─────Import─────▶│ │
│ │ └────────────────┘ │ │ Export └────────────┘ │ │
│ │ Compojure API # ├─┼─────┘ │ │
│ └────────────────────┘ │ │ │
│ Ring Lambda Adapter $ │ │ │
└────────────────────────┘ └────────────────────────┘
│ │
│ Proxy
│ │
│ ▼
│ ┌────────────────────────┐
│ │ │
│ │ │
│ │ │
│ │ │
│ ┌────────────┐ │ AWS Lambda │
└───────────Build % ─────▶│ server.jar │────Deploy──────▶│ │
└────────────┘ │ │
│ │
│ │
│ │
└────────────────────────┘

31. !

32. Problems?

33. ┌─────────────┐
│ │
│ │
│ Clojure │
│ ┌─────┼───────┐
│ │!"#│ │
└───────┼─────┘ │
│ AWS Lambda │
│ │
│ │
└─────────────┘

34. !"
github.com/trieloff/lein-aws-apigateway

35. !"
AWS API Gateway

36. !"
AWS IAM Permissions

37. Execution failed due to configuration error: Invalid
permissions on Lambda function
aws lambda add-permission
--function-name <name>
--statement-id <someid>
--action "lambda:*"
--principal "apigateway.amazonaws.com"
! docs.aws.amazon.com/cli/latest/reference/
lambda/add-permission.html

38. !

39. Tips?

40. Think small
100 LOC should be
enough for a Lambda
function. !

41. Think
modular
Two tiny functions are
better than one large
function. !

42. !"
github.com/trieloff/salvador

43. Think
Stateless
simplicity, performance,
composablity ☠

44. Be lazy
Sit, don’t stand on the
shoulders of giants. Re-
use, don’t re-invent. ♻

45. ┌──────────────────┐ ┌──────────────────┐ ┌──────────────────┐
│ │ │ │ │ │
│ Typeform │───Redirect──▶│ Excelsior │───Redirect──▶│ Salvador │
│ │ │ │ │ │
└──────────────────┘ └──────────────────┘ └──────────────────┘
▲ ▲
│ │
Spreadsheet Template
│ │
│ │
┌──────────────────┐ ┌──────────────────┐
│ │ │ │
│ S3 │ │ S3 │
│ │ │ │
└──────────────────┘ └──────────────────┘

46. Smile & Share
Community eats code for
breakfast. ☕

47. !

48. ⏰

49. AWS λ + Clojure λ = ♥

50. ! Rainbow Parentheses make " #

51. ))))))))))))*