Step-by-step: what a reverse proxy is (educational)

Step-by-step: what a reverse proxy is (educational)

A reverse proxy is a server that sits between client devices and one or more backend servers, accepting requests and forwarding them to the appropriate destination while returning responses to the clients, and this article walks through a practical, step-by-step setup to explain how it works and why you might use one.

Step 1 — choose your role and software when planning a reverse proxy deployment, start by deciding the primary role you need it to fulfil, such as load balancing, TLS termination, caching, or application firewalling, and select software that matches those needs, for example common options include.

• Nginx, which is lightweight and performs well for TLS termination and caching.
• HAProxy, which is strong for high-performance load balancing and health checks.
• Traefik, which integrates neatly with container platforms and dynamic service discovery.
• Envoy, which is feature rich and designed for modern service meshes and observability.

Step 2 — install and create a minimal configuration file, install the chosen reverse proxy using your distribution package manager or a container image, then create a simple configuration that listens on a public IP and forwards requests to a backend server on a private network, for example configure a server block or frontend to accept connections on port 80 and direct them to an internal address and port, and test the configuration with a reload or check command before proceeding.

Step 3 — connect backends and set routing rules, define how the reverse proxy discovers and routes to backend services by using static server definitions or dynamic discovery mechanisms, include health checks to prevent the proxy from sending traffic to unhealthy nodes, and consider path-based or host-based routing for multiple applications on a single public address so requests are routed to the correct internal service.

Step 4 — secure the proxy and handle TLS termination, terminate TLS at the proxy to centralise certificate management and reduce the load on backend servers, configure strong cipher suites and HTTP security headers, enable automatic certificate renewal if possible, restrict management access with firewalls or IP allow lists, and set rate limits or basic filtering to reduce noisy traffic before it reaches application servers.

Step 5 — test, monitor and maintain the reverse proxy, validate behaviour by exercising the proxy with real requests, check that client IPs are preserved if needed using headers like X-Forwarded-For, monitor metrics such as request rate, latency and error codes, rotate logs and certificates, plan for failover if the proxy itself is a single point of failure, and consult related Infrastructure posts for longer guides and reference material by visiting the Infrastructure posts. For more builds and experiments, visit my main RC projects page.