12factor app

What are 12factor app ?

In the modern era, software is commonly delivered as a service: called web apps, or software-as-a-service.

12factor app¶

The twelve-factor app is a methodology for building software-as-a-service apps that:

Update the deployment (new released container image tag)
Use declarative formats for setup automation, to minimize time and cost for new developers joining the project Have a clean contract with the underlying operating system,
offering maximum portability between execution environments
Suitable for deployment on modern cloud platforms, obviating the need for servers and systems administration, minimize divergence between development and production
enabling continuous deployment for maximum agility and can scale up without significant changes to tooling, architecture, or development practices.
The twelve-factor methodology can be applied to apps written in any programming language, and which use any combination of backing services (database, queue, memory cache, etc).

The Twelve Factor provides detailed information with background for the twelve-factor methodology.

As explained at the website, it is a highly recommended reading for any developer.

This is a high level summary of The twelve Factor

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
Build, release, run: Strictly separate build and run stages
Processes: Execute the app as one or more stateless processes
Port binding: Export services via port binding
Concurrency: Scale out via the process model
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 processes: Run admin/management tasks as one-off processes