12_factor.theory.txt

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12 FACTOR ==>           #Create isolated apps that scale up, behave as expected and easy to config.
                        #Isolated apps:
                        #  - one repo === one app
                        #  - dependency -> dependency manager:
                        #     - no system-wide dependency
                        #     - run in isolated environment (e.g. nvm|pyenv) to make sure
                        #  - local/remote backing services (databases, etc.) -> URL only
                        #     - if should communicate, export itself by listening to localhost:PORT
                        #That scale up:
                        #  - stateless/share-nothing processes
                        #  - automated:
                        #     - start on boot
                        #     - fast startup, graceful shutdown (SIGTERM or sudden death)
                        #     - timestamp releases
                        #Behaves as expected, i.e. branches are as close as possible, and easy to config:
                        #  - same people (DevOps), same tools (OS, backing services), continuous deployment
                        #     - use container (Vagrant, etc.)
                        #  - logs to stdout (branch-specific config redirects it)
                        #  - admin scripts run in same environment as the app itself (e.g. REPL)
                        #  - steps:
                        #     - build, not branch-specific: most should happen here
                        #     - release, branch-specific: only adds config (ENVVAR-only, not in code)
                        #     - run: should be minimalistic