Adventures in Umbrella App Design

An Experience Report on wacky things I've tried when building Umbrella projects.

Transcript

1. Adventures in Umbrella App Design Desmond Bowe NYC Elixir Meetup September 28, 2017
2. Elixir Training • Basics • OTP • Design / Architecture EMPEX Founder
3. ☂ "Umbrella projects are used to build applications that run together in a single repository.” - elixirlang.org
4. ☂ my_app/ _build/ config/ deps/ lib/ my_app/ my_app.ex log/ priv/ test/ mix.exs mix.lock _build/ apps/ my_app/ config/ deps/ lib/ my_app/ my_app.ex log/ priv/ test/ mix.exs mix.lock photo_service/ config/ deps/ mix.exs mix.lock Normal App Umbrella App
5. ☂ Calling Functions Across Apps ☠
6. Should I Use One?
7. Experience Report Twig Crevalle
8. Example 1: Twig Infrastructure • landing site • admin site • backoffice Needs • share assets across web frontends • web frontends need data from different services
9. Twig 1st approach • 3 phoenix applications • separate assets app apps/ admin/ assets/ landing/ mother_brain/
10. Twig • share js, css, images • assets app is styleguide • hard to share templates • redundant dependencies • painful upgrades
11. Twig 2nd approach • all web apps in single OTP app apps/ mother_brain/ site/ config/ web/ admin/ assets/ landing/ controllers/ views/ endpoint.ex router.ex web.ex
13. Twig • share js, css, images • assets app is styleguide • easy to share templates • streamlined dependencies • simpler authentication • configuration • file organization is important to reduce cognitive load
14. Example 2: Crevalle Infrastructure • many distinct user-facing apps with individual datastore Needs • easily spin up new projects • reuse functionality • bird’s eye view of company
15. Crevalle Approach • each project is its own app • shared functionality (e.g. image processing, authentication) is extracted to its own app apps/ chitta/ crux/ oauth/ postfactor/ pulse/ config/ lib/ web/
16. Crevalle • easy to create/deploy projects • simple integration testing • deploy entire company platform at once
17. Crevalle if your entire company is an umbrella app, your company’s individual services are their own OTP apps • teams work on specific app • apps are individually deployed to appropriate hardware • monolith + services • no more issues of internal API versions, data serialization
18. Anti-Patterns extracting all services to their own app because Boundaries
19. Rules of Thumb for OTP apps • it has its own datastore • it has particular resource needs (eg high CPU load) • shared functionality
20. successful Elixir application design means thinking in terms of Applications
21. successful Elixir application design means thinking in terms of Applications we are still figuring this out.
22. successful Elixir application design means thinking in terms of Applications we are still figuring this out. join us at the bar!
23. thanks. @desmondmonster