Tuesday, August 16, 2016

Twelve Important Design Patterns

Read this: http://12factor.net/

Then. After reading it. Read it again to be sure you've got it. It's dense with best practices.

Now that you've read it, make yourself a Quality Engineering checklist.

I. Codebase: One codebase tracked in revision control, many deploys
II. Dependencies: Explicitly declare and isolate dependencies
III. Config: Store config in the environment
IV. Backing services: Treat backing services as attached resources
V. Build, release, run: Strictly separate build and run stages
VI. Processes: Execute the app as one or more stateless processes
VII. Port binding: Export services via port binding
VIII. Concurrency: Scale out via the process model
IX. Disposability: Maximize robustness with fast startup and graceful shutdown
X. Dev/prod parity: Keep development, staging, and production as similar as possible
XI. Logs: Treat logs as event streams
XII. Admin processes: Run admin/management tasks as one-off processes

If your app doesn't follow all of these patterns, you've got technical debt to work off. Start by posting the debt remediation stories in Jira (or whatever you're using.)

I've got config issues left, right, and center. Numerous assumptions include the URL's for RESTful services on which my RESTful services rely: this is not good.

Some of these things, however, are a done deed in the Python/Flask world with no real thinking required.

  • Build, release, run - done
  • Processes - done
  • Port binding - done
  • Disposability - done

Other things require some care. And the config is something that I've really got to fix.