Custom start command

Custom start command

The auto builder correctly guesses the start command in the vast majority of cases. If it doesn't, or if you want specific behavior, you can override it from Settings → Start command.

Common examples

# Next.js in standalone mode, if automatic detection fails
node .next/standalone/server.js

# Node.js application supervised by PM2
npx pm2-runtime start ecosystem.config.js

# Python API served by Gunicorn
gunicorn app:app --bind 0.0.0.0:$PORT --workers 2

# Already-compiled Go binary from the build
./main --port $PORT

The port counts twice

Your application must listen on the address 0.0.0.0 (not localhost) and on the port defined by the PORT environment variable. Traefik uses that port to route traffic to your pod.

const port = process.env.PORT || 3000;
app.listen(port, "0.0.0.0");

A start command that ignores PORT and listens hardcoded on 3000 will work as long as the port configured in Webgune stays 3000. But it will break silently as soon as that port changes.