3 posts tagged with "rails"

You have a Rails app. It has a web service, a Postgres database, and a Sidekiq worker, and it runs on your laptop with a docker-compose.yml you copy-pasted from a blog post two years ago. You want it on Fibe: a real HTTPS URL, live logs, a terminal, source pulled from your repo, secrets that aren't sitting in plaintext, and migrations that run before anyone hits the app.

This post does the whole conversion, top to bottom: we start from a realistic raw Compose file and turn it, one decision at a time, into a polished, launchable template — the kind you'd publish to the Bazaar. By the end you'll have a file you can click Launch on, and a mental model for why each label is there.

Fibe runs Docker development environments for people, and the brain of that is a Rails modular monolith. It decides when a Playground is healthy, when to tear one down, when a Wallet has run dry, and when a state transition is illegal and should be refused. That code is dynamic Ruby, and it is load-bearing in the most literal sense: get a state transition wrong and you destroy someone's running environment.

So we type it — but not all of it. Typing every line of a Rails app is a great way to spend a quarter and ship nothing. We type the parts where a wrong shape becomes a wrong outcome, and leave the rest dynamic. This post is about where that line is.

Every few months someone asks when Fibe is going to "break the monolith into services." It's a reasonable question. We provision Docker hosts, route TLS, run AI coding agents, charge money, and reconcile container state every sixty seconds — all in one Rails app that ships in one deploy. On paper, the thing the microservices talks warn you about.

It isn't, and the reason is boring in the best way: the monolith is split into ten-plus enforced domains whose boundaries are checked in CI, so a call from the billing domain into the provisioning domain's internals fails the build like a syntax error would. We get the part of microservices that matters — domains that can't secretly reach into each other — and skip the part that hurts: a network between every method call.