12 Factor App: Red Dot Ruby Conf

Transcript

1. May 18th 2012 Richard Schneeman @schneems the 12factor App Monday,

   May 21, 12

2. Hello Monday, May 21, 12

3. 㟬޷ Monday, May 21, 12

4. It’s Friday Monday, May 21, 12

5. whoami • @Schneems • BSME with Honors from Georgia Tech

   • 5 + years experience Ruby & Rails • Work for @Heroku • Rails 3.1, 3.2, & 4.0 contributor • 3 + years technical teaching • UT Austin Monday, May 21, 12

6. Twelve Factor • Can apply to any language • Speeds

   up deployment, makes scaling easier & keeps apps clean • Developed over direct exposure to the deployment of hundreds of thousands of apps Monday, May 21, 12

7. Monday, May 21, 12

8. Code + Methodology • Speed and confidence through: • Development

   environment • Staging environments • Consistent codebase practices • Quick access to logs and metrics • Easy scaling architecture Lets take a look Monday, May 21, 12

9. Config Monday, May 21, 12

10. Config • What varies between deploys • resource strings to

    databases • credentials to S3, twitter, facebook, etc. • canonical values, hostname • security tokens Monday, May 21, 12

11. Config Does NOT go in source control Monday, May 21,

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12. secrets in source control aren’t secret Monday, May 21, 12

13. Open source- able? Monday, May 21, 12

14. Rotateable Secure Keys Monday, May 21, 12

15. Config: Development $ cat .env S3_KEY=FOONVBAR FACEBOOK_APP_ID=281502345249818 FACEBOOK_SECRET=d59c2a439f4be49cf1 Monday, May

    21, 12

16. Config: Development $ foreman run rails console ruby-1.9.3 > puts

    ENV[“S3_KEY”] ruby-1.9.3 > “FOONVBAR” Monday, May 21, 12

17. Config: Development $ foreman start $ cat Procfile web: bundle

    exec unicorn -p $PORT -c ./config/unicorn.rb worker: bundle exec rake jobs:work Monday, May 21, 12

18. Config: Production • Heroku ‘config’ • Read from environment $

    heroku config:add S3_KEY=FOONVBAR > puts ENV[‘S3_KEY’] > “FOONVBAR” Monday, May 21, 12

19. Config: Production • On A VPS • Use Foreman •

    Add values directly to command $ S3_KEY=FOONVBAR rails console ruby-1.9.3 > puts ENV[‘S3_KEY’] ruby-1.9.3 > “FOONVBAR” Monday, May 21, 12

20. development vs. production Monday, May 21, 12

21. Development • As close to production as possible • Same

    data-stores (postgres, memcache) • Same language versions (Ruby 1.9) • Real/consistent data Monday, May 21, 12

22. Development • Real/consistent data $ heroku db:pull Monday, May 21,

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23. Development • Real/consistent data $ rake users:drop $ rake users:create

    # ... $ rake master:create Monday, May 21, 12

24. Bundler • Bundle versions specified • ~> • Use semantic

    versioning • Prevent unexpected library changes gem 'twitter', '~> 2.0.2' gem "koala", '~> 1.2.1' gem 'tumblr-api', '~> 0.1.4' # ... Gemfile Monday, May 21, 12

25. README.md • Living document • Standardize dev environment • Instructions

    for external dependencies • Instructions for starting processes • Problem with dev environment? • Put the fix in the readme $ brew install memcache $ foreman start Monday, May 21, 12

26. but... it worked in development Monday, May 21, 12

27. Staging • A “production like” environment • Try stuff out

    here before production Monday, May 21, 12

28. Staging [remote "production"] url = [email protected]:hourschool.git fetch = +refs/heads/*:refs/remotes/heroku/* [remote

    "staging"] url = [email protected]:hourschool-drama.git fetch = +refs/heads/*:refs/remotes/heroku/* .git/config Monday, May 21, 12

29. Staging $ git push --remote staging $ cap deploy staging

    Monday, May 21, 12

30. Stage with Data Production Development Staging Monday, May 21, 12

31. Multiple Staging [remote "production"] # ... [remote "staging"] # ...

    [remote "staging-bill"] # ... [remote "staging-ted"] # ... .git/config Monday, May 21, 12

32. 1 app 1 codebase Monday, May 21, 12

33. Git • All code for the app goes in one

    repository • Split out easily reusable code into separate libraries • i.e. github.com/schneems/wicked Monday, May 21, 12

34. Git Flow • New feature? • Put it in a

    branch • Refactoring code? • Put it in a branch • Need a New Demo? • Put it in a branch Monday, May 21, 12

35. Branches • Keep the codebase clean • Testing feature branches

    in staging $ git co -B schneems/solr_search $ git push --remote staging schneems/solr_search:master Monday, May 21, 12

36. logging Monday, May 21, 12

37. Logging • Production errors still happen • Tail logs to

    find the cause • Use a logging service to dig in deeper $ heroku logs --remote production --tail Monday, May 21, 12

38. Logging • Record Logs & Errors • New Relic (rpm)

    • Scout • Loggly • Papertrails • Airbrake (hoptoad) Monday, May 21, 12

39. Logging • Help when the problem is intermittent • Too

    much traffic for tail to be effective • Provide additional insights Monday, May 21, 12

40. Error Pages • Admins get error + Backtrace Couldn't find

    Course with ID=chunkybacon Details Params: {"action"=>"show", "controller"=>"courses", "id"=>"chunkybacon"} Backtrace: lib/active_record/relation/finder_methods.rb:304:in `find_one' Monday, May 21, 12

41. Custom Error Pages • Admins get error + Backtrace Couldn't

    find Course with ID=chunkybacon Details Params: {"action"=>"show", "controller"=>"courses", "id"=>"chunkybacon"} Backtrace: lib/active_record/relation/finder_methods.rb:304:in `find_one' Monday, May 21, 12

42. scale out Monday, May 21, 12

43. Web Instances • Handle web requests • More instances =

    more throughput • Worker instances can help offload tasks Monday, May 21, 12

44. Workers • Push long tasks that don’t fit in request

    cycle to a worker • Workers have the same code, but don’t serve web content • Perfect for • Delayed emails • Image Processing • etc. Monday, May 21, 12

45. Workers • Use with a queuing system • Resque (redis)

    • DelayedJob (sql) • Sidekiq • Enqueue from the web server • User signs up, queue email • Dequeue & run on the worker • Process next item in queue Monday, May 21, 12

46. the web app demystified Monday, May 21, 12

47. Twelve Factor Monday, May 21, 12

48. Twelve Factor • Web apps have a contract with their

    platform • When the right development methods are used, their app can be cleanly deployed quickly Monday, May 21, 12

49. Do You Like? • Minimizing new developer overhead? • Running

    in multiple environments? • Easily scaling without tooling, architecture or development headaches? • Having the latest updates available to users at a moments notice? Read more at 12factor.net Monday, May 21, 12

50. Questions? @schneems Monday, May 21, 12

51. 12factor.net • Codebase • One codebase tracked in revision control,

    many deploys • Dependencies • Explicitly declare and isolate dependencies • Config • Store config in the environment • Backing Services • Treat backing services as attached resources Monday, May 21, 12

52. 12factor.net • Build, Release, Run • Strictly separate build and

    run stages • Process • Execute the app as one or more stateless processes • Port Binding • Export services via port binding • Concurrency • Scale out via the process model Monday, May 21, 12

53. 12factor.net • Disposability • Maximize robustness with fast startup and

    graceful shutdown • Dev/Prod Parity • Keep development, staging, and production as similar as possible • Logs • Treat logs as event streams • Admin Process • Run admin/management tasks as one-off processes Monday, May 21, 12