Exploring location block priorities

This problem frequently occurs when using multiple location blocks in the same server block: configuration does not apply as you thought it would.

As an example, suppose that you want to define a behavior to be applied to all image files that are requested by clients:

location ~* .(gif|jpg|jpeg|png)$ {
    # matches any request for GIF/JPG/JPEG/PNG files
    proxy_pass http://imageserver; # proxy pass to backend
}

Later on, you decide to enable automatic indexing of the /images/ directory. Therefore, you decide to create a new location block, matching all requests starting with /images/:

location ^~ /images/ {
    # matches any request that starts with /images/
    autoindex on;
}

With this configuration, when a client requests to download /images/square.gif, NGINX will apply the second location’s block only. Why not the first one? The reason is that...