v4: the devcontainer starts several gerbeur instances side by side, so that signing in from one to another can be tried on one machine — the dev environment ran a single instance. dev/instances.ts lists them (gerbeur on :3000 and :8000, musique on :3001 and :8001), and dev/start.ts starts an API server, restarted on change, and a Vite server for each instance it's given, by one rule: instance <name> keeps api/sql/<name>.db and api/uploads/<name>/, reads .env, and takes its ports and what sets it apart from its entry, with federation allowed over http on localhost. It prefixes each line of output with the instance's name, and stops every server when one stops, such as a Vite server whose port is taken. The devcontainer is now a compose project (.devcontainer/compose.yaml): the workspace, a one-shot install that runs deno install and draws the icons once, and a service per instance running dev/start.ts for it, all on the host's network as before and sharing Deno's cache through a volume. ffmpeg moves from a feature into the Dockerfile, since the instances' services get no features, and docker-outside-of-docker gives the workspace's terminal their logs and restarts. Outside the devcontainer, deno task dev starts them all, or those named. Each Vite server keeps its own dependency cache. The existing dev uploads move to api/uploads/gerbeur/.

dev/start.ts was checked by hand: musique starting alone on a fresh database, an unknown name refused, a taken port stopping both servers, and Ctrl+C or SIGTERM leaving no server behind. The compose project couldn't be run here (no Docker in the workspace): its YAML parses and resolves as intended, but it is untested; tsc, eslint, deno check, deno fmt, deno lint and doc:lint, which now covers dev/, are clean.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

README.md

@@ -31,15 +31,32 @@ cp .env.example .env
 
 ### Run
 
+In the devcontainer, the dev instances listed in
+[`dev/instances.ts`](dev/instances.ts) start with the container, each a service
+of [`.devcontainer/compose.yaml`](.devcontainer/compose.yaml): `gerbeur` at
+[http://localhost:3000](http://localhost:3000), `musique` at
+[http://localhost:3001](http://localhost:3001). They run side by side so that
+signing in from one instance to another can be tried on one machine, and from
+the workspace's terminal:
+
 ```sh
-deno task dev
+docker compose -p gerbeur-dev logs -f musique   # follow an instance
+docker compose -p gerbeur-dev restart gerbeur   # restart one
 ```
 
-This starts both the API server (port 8000, with file watching) and the Vite dev
-server (port 3000) concurrently.
+Outside the devcontainer, or with those services stopped, `deno task dev` starts
+them all, and `deno task dev gerbeur` only those named.
 
-Open [http://localhost:3000](http://localhost:3000). On first run a default
-`admin` / `admin` account is created — change the password immediately.
+Each instance has an API server, restarted on change, and a Vite server, and its
+output is prefixed with its name. They follow one rule
+([`dev/start.ts`](dev/start.ts)): instance `<name>` keeps its database in
+`api/sql/<name>.db` and its uploads in `api/uploads/<name>/`, reads `.env`, and
+takes what sets it apart (ports, site name, emoji, style) from its entry. A new
+instance is an entry in `dev/instances.ts` and a service in `compose.yaml`.
+
+On first run each instance creates a default `admin` / `admin` account — change
+the password immediately. To let one instance's users sign in to another, trust
+it on the other's `/manage`.
 
 ### Environment variables
 
@@ -141,13 +158,14 @@ can reach each other. An admin decides who comes in, on `/manage`:
 - users of **any other** instance join with an invite, from the register page,
   and sign in without one afterwards.
 
-To try it on one machine, run two instances on different ports with
+`deno task dev` runs several instances on one machine (see [Run](#run)), with
 `GERBEUR_FEDERATION_ALLOW_PRIVATE=1`, which lets them reach each other over
 plain http on localhost. Never set it in production.
 
 ## Project structure
 
 ```
+dev/               # The dev instances (instances.ts) and their launcher (start.ts), for `deno task dev`
 shared/            # Imported by both halves: API and socket types, limits, permissions
   test/            # Tests of shared/ (Deno): test/<module>.test.ts
 locales/           # Lingui catalogues (en, fr): the interface's and the emails' messages
@@ -171,8 +189,8 @@ api/
     migrations/    # Versioned schema migrations
   test/            # Backend tests (Deno): test/<layer>/<module>.test.ts
   sql/
-    gerbeur.db     # SQLite database (not committed)
-  uploads/         # User-uploaded files — avatars, dumps, thumbnails, … (not committed)
+    gerbeur.db     # SQLite database (not committed); <name>.db per dev instance
+  uploads/         # User-uploaded files — avatars, dumps, thumbnails, … (not committed); <name>/ per dev instance
 src/               # React frontend (Vite)
   config/          # API base URL, default feed tab, player mode, instance settings
   pages/           # One component per route, nothing else