Using a Reverse Proxy for Local Development

A reverse proxy acts as an intermediary server that forwards client requests to one or more backend servers, then returns the server's response to the client. While reverse proxies are commonly used in production environments for load balancing, SSL termination, and caching, they're also incredibly useful for local development workflows.

In a typical development setup, you might run multiple services on different ports: your frontend on port 3000, your API on port 8000, and perhaps a WebSocket server on port 8080. Remembering these port numbers and dealing with CORS issues can be frustrating. A local reverse proxy like nginx or Caddy can solve these problems elegantly.

With a reverse proxy, you can map clean URLs to your services. Instead of accessing http://localhost:3000 for your frontend and http://localhost:8000/api for your backend, you can configure the proxy to serve everything from http://myapp.local, with /api routes automatically forwarded to your backend service. This more closely mimics a production environment and eliminates CORS issues since everything appears to come from the same origin.

Setting up a basic reverse proxy is straightforward. With Caddy, for example, you can create a simple Caddyfile that defines your routing rules. The proxy can also handle SSL certificates for local HTTPS development, which is increasingly important as many modern web APIs require secure contexts. Whether you're working on a microservices architecture or just want a cleaner development experience, a local reverse proxy is a tool worth mastering.