12 Factor applications

• offers a set of best practices for building modern software applications

• created by the platform heroku

1. Codebase:

• Have one place to keep all your code, and manage it using version control like Git.

1. Dependencies:

• List all the things your app needs to work properly, and make sure they're easy to install.

• maven/gradle

1. Config:

• Keep important settings like database credentials separate from your code, so you can change them without rewriting code.

• Spring config/custom remote config, config maps, secrets

1. Backing Services:

• Use other services (like databases or payment processors) as separate components that your app connects to.

• Other connected microservices

1. Build, Release, Run:

• Make a clear distinction between preparing your app, releasing it, and running it in production.

• Jenkins/teamcity/github actions CI/CD, Blue-Green/Canary

1. Processes:

• Design your app so that each part doesn't rely on a specific computer or memory. It's like making LEGO blocks that fit together.

• Stateless APIs

1. Port Binding:

• Let your app be accessible through a network port, and make sure it doesn't store critical information on a single computer.

• NAT Gateway/Service discovery/Service Mesh

1. Concurrency:

• Make your app able to handle more work by adding more copies of the same thing, like hiring more workers for a busy restaurant.

• Docker/Podman containers, idempotancy, immutability

1. Disposability:

• Your app should start quickly and shut down gracefully, like turning off a light switch instead of yanking out the power cord.

• Kubernetes orchestration for containers

1. Dev/Prod Parity:

• Ensure that what you use for developing your app is very similar to what you use in production, to avoid surprises.

• Separate PreProd/Prod pipelines and environments

1. Logs:

• Keep a record of what happens in your app so you can understand and fix issues, like a diary for your software.

• Fluentd/Splunk

1. Admin Processes:

• Run special tasks separately from your app, like doing maintenance work in a workshop instead of on the factory floor.

Links

• https://12factor.net/

• https://www.bmc.com/blogs/twelve-factor-app/

• https://cloudposse.com/12-factor-app/

• https://reflectoring.io/spring-boot-12-factor-app/

• https://youtu.be/94PxlbuizCU The Twelve Factor app: Best Practices for Java Deployment by Joe Kutner