Watch Party (Frontend + Backend)

Watch Party is a small full-stack app for synchronized viewing with a live timer and episode control.

Features

• Live timer with server-synced clock and schedule-driven start/end.
• Episode selector (set current episode + optional custom start time).
• Time-skew banner (warns when client clock is off).
• Debug-only logging overlay and error toasts for API failures (enable with FRONTEND_MODE=debug / VITE_APP_MODE=debug).

Prerequisites

• Docker + Docker Compose plugin.
• Node.js 20+ (for local frontend dev/test).
• Go 1.22+ (for local backend dev/test).
• A .env file at repo root (see template below).

Deploy (compose)

docker compose build
docker compose up -d

Open: http://<mac-mini-LAN-IP>:3000/watch-party/

Health checks:

• Web (nginx): curl http://<mac-mini-LAN-IP>:3000/
• API via web proxy: curl http://<mac-mini-LAN-IP>:3000/api/healthz
• API direct (inside network): curl http://api:8082/healthz

Logs:

docker compose logs -f migrate
docker compose logs -f api
docker compose logs -f web
docker compose logs -f db

Architecture:

router → Debian nginx (TLS) → Mac mini :3000 → [web nginx ↔ api ↔ db]

---

Repository Layout

.
├── docker-compose.yml      # single compose for web + api + db + migrate
├── .env                    # stack configuration (see template below)
├── backend/                # Go API + migrations
│   ├── cmd/
│   │   ├── migrate/        # one-off migration binary
│   │   └── server/         # API server (Gin)
│   ├── db/migration/       # SQL migrations (0001_init.sql, etc.)
│   ├── Dockerfile          # builds server + migrate
│   └── go.mod / go.sum
└── frontend/               # Vite + React + TS
    ├── Dockerfile          # Vite build → Nginx runtime (envsubst for proxy)
    ├── ops/                # container runtime bits
    │   ├── entrypoint.sh
    │   ├── nginx.conf      # (optional/manual)
    │   └── nginx.conf.template  # uses BACKEND_ORIGIN
    ├── src/, public/, vite.config.ts, package*.json, tsconfig*.json

---

Services (Compose)

• web: Nginx serving the built SPA, and proxying /api/* to api:8082 (Docker DNS)
• api: Go server (Gin), listens on :8082, health at /healthz
• migrate: one-off job that runs the migrate binary, applies SQL from backend/db/migration
• db: PostgreSQL 16 (internal only)

Only web is published to your LAN (port 3000 by default). api and db are internal to the compose network.

---

.env (template)

##################
## Frontend env ##
##################
WEB_PORT=3000
PUBLIC_BASE_PATH=/watch-party/
BACKEND_ORIGIN=http://api:8082

#################
## Backend env ##
#################
# Postgres (container)
POSTGRES_DB=watchparty
POSTGRES_USER=admin
POSTGRES_PASSWORD=change-me
TZ=Asia/Tokyo
COMPOSE_PLATFORM=linux/arm64/v8

# Backend server
ADDR=:8082
GIN_MODE=release
PGHOST=db
POSTGRES_PORT=5432
PGSSLMODE=disable

Why mixed names? The current Go code builds its DSN from PGHOST, POSTGRES_PORT, POSTGRES_USER, POSTGRES_PASSWORD, POSTGRES_DB, and PGSSLMODE.

---

Debian Nginx (public reverse proxy)

Terminate TLS on Debian and forward to the Mac mini:

# Serve the SPA under /watch-party/
location /watch-party/ {
  proxy_pass http://<mac-mini-LAN-IP>:3000/watch-party/;
  proxy_set_header Host $host;
  proxy_set_header X-Forwarded-For $remote_addr;
}

# Proxy API via the web container (keeps same-origin from browser POV)
location /api/ {
  proxy_pass http://<mac-mini-LAN-IP>:3000/api/;
  proxy_set_header Host $host;
  proxy_set_header X-Forwarded-For $remote_addr;
}

Security headers & HSTS on Debian are recommended.

---

Local Development (hot reload)

See per-service READMEs:

• Frontend: frontend/README.md
• Backend: backend/README.md

---

Notes & Conventions

• Only web is exposed to the LAN. api and db are exposed internally.
• The frontend does not use host.docker.internal; it proxies to api:8082 by Docker DNS.
• Backend healthcheck probes http://localhost:8082/healthz and the server binds ADDR=:8082.
• Migrations live in backend/db/migration/ and are applied by the migrate container at startup.
• Vite base path is controlled by PUBLIC_BASE_PATH (e.g., /watch-party/).

---

Quick Test Endpoints

# Latest health:
curl http://<mac-mini-LAN-IP>:3000/api/healthz

# Current show (if table seeded and current_ep=true):
curl http://<mac-mini-LAN-IP>:3000/api/current

---

Troubleshooting

• Migrate “hangs” / API starts instead
  Ensure the backend image uses CMD (not ENTRYPOINT) and compose sets:

  migrate:
    command: ["/app/migrate"]
  api:
    command: ["/app/server"]
  

• 404 for deep links under /watch-party/
  Confirm SPA fallback is active in frontend/ops/nginx.conf.template and Vite base matches PUBLIC_BASE_PATH.
• DB not reachable
  Check .env values match the mixed DSN env names. PGHOST=db, POSTGRES_PORT=5432, etc.
• CORS issues
  There shouldn’t be any—browser hits web, which proxies to api, so it’s same-origin.

---

License

MIT