nginx config files grow. What starts simple gets layers added on top: another reverse proxy, TLS settings, routing logic that branches and branches again.
Before long you're looking at 20+ location blocks and can't say off the top of your head which one handles which request. You add a single add_header line and some other header silently disappears. You fix an alias path and prod throws 404s while staging is fine. nginx -t says "syntax is ok." But you don't feel ok about it.
Every config change comes with a quiet dread: will this break something? And that dread usually has a basis. nginx config mistakes are silent. Nothing shows up in the error log. The browser gets a normal-looking response. You don't find out something is broken until much later.
nginx itself is well-documented, but the ecosystem around it is harder to survey. Validation tools, config generators, test frameworks — searching turns up scattered information. This article organizes the common pain points into six categories and maps the tools that address each one.
Problem 1: Prevent config mistakes upfront
