Test your knowledge: Nginx Config Mechanics

Review

1. Requests hit both location /images/ and location /images/avatars/. Which serves the request?

   NGINX remembers the longest prefix that matched and only replaces it when a longer one matches. Order matters only for regex locations and exact matches ( =), which short-circuit everything.
2. What does the = modifier on a location do?

   An exact-match location terminates the matching algorithm the moment it hits. For high-traffic URIs like / it skips regex evaluation entirely.
3. Why is map the recommended way to branch on request values instead of if?

   map evaluates when the variable is first read, outside the content-phase re-entry trap that makes if unpredictable. It produces one clean variable you can use anywhere — the config stays declarative.
4. A directive set at the server level and again inside one location — what happens?

   Scalar directives inherit downward and are replaced when re-declared in a nested context. Array-type directives (like access_log or add_header) accumulate when repeated at the same level — but a nested context that declares any of them cancels the entire inherited set (the add_header trap). listen does not inherit at all.
5. A request arrives with a Host header matching no server_name. Which server block handles it?

   listen flags mark the default: the first block for the port unless another declares default_server. It is the catch-all — point it at a 444 or a stub when you do not want stray Host headers served.
6. What does include conf.d/*.conf; give a growing configuration?

   include pulls files into the parse at load time — same validation, same tree, but concerns stay separate: one conf.d file per vhost, one per shared setting. Globs expand in sorted order, keeping merges predictable.