Fighting Continuous Entropy

What happens when you leave a codebase alone for a year? Would you expect it to still work? What about 5 years? 10 years?

If you've experienced you know the answer: it's a whole bunch of work to replatform the code to something more modern, more supported.

It doesn't have to be like this.

What if we used continuous integration and deployment techniques to ensure an easier future for ourselves and our future teams? Let's discuss a world in which we can write systems that, to a large degree, can look after themselves when we're not looking.

In this session, we'll explore code rot, continuous deployment, and the tools (automated and otherwise) you can use to keep your code alive for a bit longer.

Transcript

6. !
7. NOVEMBER FIFTEEN, NINETEEN NINETY-FIVE
8. SIXTEEN => SOXTEEN
9. SIXTEEN => SOXTEEN
10. TWO THOUSAND SOXTEEN
11. ▸ No source code (written in an older language) ▸ Runs in a green screen terminal, ▸ Has to be emulated.
12. FIGHTING CONTINUOUS ENTROPY ADVENTURES IN CONTINUOUS DELIVERY @GARYFLEMING
13. WHAT IS ENTROPY? "a thermodynamic quantity representing the unavailability of a system's thermal energy for conversion into mechanical work, often interpreted as the degree of disorder or randomness in [a closed] system."
14. WHAT IS ENTROPY? "Disorder of a closed system"
15. SYSTEM EXPERIMENT: FISHES
16. SYSTEM EXPERIMENT: FISHES AND TIME ▸ 10 minutes? ▸ 10 hours? ▸ 10 days? ▸ 10000 years?
17. ENTROPY IN SOFTWARE
18. !
19. MULTI-FACETED
20. Problem KNOWING WHETHER YOUR SOFTWARE IS DEPLOYABLE
21. BRIEF INTRO TO CI/CD
22. CONTINUOUS INTEGRATION All developers/testers merge their code to a shared mainline at least once a day.
23. CONTINUOUS INTEGRATION Related: ▸ Trunk-Based Development ▸ Feature Toggles
24. IF IT HURTS, DO IT MORE OFTEN.
25. CONTINUOUS DEPLOYMENT All changes go to production; safely, quickly, and sustainably.
26. CONTINUOUS DEPLOYMENT Related: Blue-Green releases.
28. Problem DEPENDENCY UPDATES
29. IF IT HURTS, DO IT MORE OFTEN.
30. IDEA UPDATE DEPENDENCIES DAILY
31. CONTINUOUS REGENERATION
32. CONTINUOUS REJUVENATION
33. EXPERIMENT: DEPENDENCY UPDATE DAILY ▸ Update ▸ Build and test ▸ Commit/Revert ▸ Commit causes CD to happen
34. OUTCOME: DEPENDENCY UPDATE DAILY Mostly success! ▸ Some Major Version upgrades would need intervention, ▸ Temporary exclusions are important, ▸ Found unexpected end-to-end issues!
35. DEPENDENCY UPDATES: OTHER LANGUAGES ▸ Single versioned: Maven, Gradle, packages.config e.g 5.4.1 3.0-ALPHA 1.3.2
36. DEPENDENCY UPDATES: OTHER LANGUAGES ▸ Ranges and Lock files: gem/bundler, most JS frameworks. >=5.4.1 3.* [3.7.1)
37. DEPENDENCY UPDATES: OTHER LANGUAGES ▸ Possibly open: pip, some JS frameworks, gem some-dep a-different-dep
38. ALWAYS USE A LOCK FILE! Avoid "It works on my machine"
39. RECENT DEVELOPMENTS ▸ Dependabot ▸ Atomist
40. GOOD TESTS ARE ESSENTIAL!
41. Problem RUNTIME ROT
42. ROT WILL SET IN ▸ JVM ▸ .NET ▸ NPM version
43. THE CONTINUOUS NOW
44. INTERMEDIARY TOOLING ▸ Java -> Jabba ▸ Ruby -> RVM ▸ Node -> NVM ▸ Python -> Virtualenv (to some degree)
45. Problem STANDING SERVERS
46. Problem STANDING SERVERS
47. AVOID SNOWFLAKE SERVERS ▸ Hard to Reproduce ▸ Hard to Modify ▸ Require manual processes, auditing, and docs.
48. IF IT HURTS, DO IT MORE OFTEN.
49. INFRASTRUCTURE AS CODE ▸ Chef/Puppet/Ansible ▸ Terraform ▸ Containerisation ▸ Various cloud toolkits
50. ENGINEERING PRACTICE ▸ Daily Deletion ▸ Chaos Engineering ▸ Dev Laptop Wipes
51. CAUTION: TAKE THE UPDATES
52. Problem LANGUISHING LANGUAGES
53. Problem LANGUISHING LANGUAGES
55. AVOIDING OBSOLESCENCE ▸ Move to new versions, ▸ Cautiously embrace new languages, ▸ Design language agnostic APIs
56. DESTROY YOUR MICROSERVICES
57. Problem PEOPLE COME AND GO.
58. Problem PEOPLE COME AND GO.
59. IF IT HURTS, DO IT MORE OFTEN.
60. People Prepping RETROS
61. People Prepping DOMAIN KNOWLEDGE ▸ User Story Maps ▸ Example mapping
62. People Prepping STAFF LIQUIDITY MATRICES
64. People Prepping BIGGER CHANGES
65. EVERYTHING IS ROTTING...
66. ...YOU CAN GET BETTER
67. THANK YOU @GARYFLEMING #TALK-CONTINUOUSENTROP -> SELFCONF.SLACK.COM