continuous integration

lion taming / code taming

old way

• deploy by hand
• hack till it works
• confusion - special decisions

lion taming - understand, conditioning, behaviour -> response trust

• understand -> deploy hard
• conditioning -> CI
• push -> test-> green
• happy
• trust - it works in live

team

• committed to quality
• everyone deploys
• identical environments
• everyone is responsible

working code

• tests

  • unit, acceptance (user’s viewpoint)
  • quick, reliable
  • slow tests -> fail

• no pylint fail

• commit often, rollback

• both dev + qa responsible

• don’t let tests rot

• break tests - triage: right now vs asap

repeatable build

• automated
• no manual changes

deploy

• script <env> <version>
• not just code - config infrastructure
• always follow the pipeline - even in emergencies

rollback

• you will break stuff!
• blue is the new green (blue is working on live)
• canary servers
• databasea - keep backwards compatible

release

• last step - automatic
• small changes, frequent, get experience, less risk - maybe, maybe just to staging server

tips

• split in components
• rehearse releases - get very good at them
• manage and test infrastructure - eg test email sending
• all environments equal (vagrant)
• automate everything, if really not possible then document, but will drift