Nginx Custom Error Pages – Efficient Definition Methods

custom-errorsnginx

I created some custom 4xx and 5xx HTML error pages for most errors listed on the Wikipedia page. I'd like to install them on any nginx server I set up, without impacting performance too much.

Following the documentation I came up with this configuration directive for an error:

error_page 404 /nginx/404.html;
location = /nginx/404.html {
        alias /usr/share/nginx/errors/404.html;
        internal;
}

I put this in /etc/nginx/snippets/errors.conf and can include the snippet in all my server blocks.

This works great, however…

It prepends nearly 50 location directives to every server block on the box.

Is this excessive, and is there a more performance-friendly way to achieve the same thing? I avoided server-side includes, if statements, and rewrites thinking it would require more server resources.

Best Answer

When you don't map each error page to it's own location you can do with a single location directive:

error_page 402 /error/402.html;
error_page 403 /error/403.html;
error_page 404 /error/404.html; 
... etc. 

location = /error/ {
        alias /usr/share/nginx/errors/;
}

Related Solutions

Nginx – Trouble with nginx and serving from multiple directories under the same domain

The root directive is the problem here. Quote from the doc:

note: Keep in mind that the root will still append the directory to the request so that a request for "/i/top.gif" will not look in "/spool/w3/top.gif" like might happen in an Apache-like alias configuration where the location match itself is dropped. Use the alias directive to achieve the Apache-like functionality.

Basically, only use root for real roots: if the content is to be at / use root. If it's going to end on a subfolder, use alias:

location  /map/ {
  alias  /home/user/public_html/map/;
}

Also check what user nginx is running as and make sure that this user can access /home/user/public_html/map

Nginx custom 404 error page for virtual host

Firstly, set your root directive outside the location block - in this case, above the error_page - directive. See the nginx pitfalls page. The reason for this is that many directives (including error_page) need to know paths relative to something - and all paths are assumed to be relative (i.e. /404.html is not in the root of your file system - it is relative to your document root).

server{
    #listen 80; - not needed
    server_name www.foo.com;
    root    /srv/www/foo/public_html;
    expires     1M;
    access_log  /srv/www/foo/logs/access.log;
    error_log   /srv/www/foo/logs/error.log;

    error_page 404 /404.html;

    location / {
        index   index.html;
        rewrite ^/(.*)/$ /$1 permanent;
        try_files "${uri}.html" $uri $uri/ =404;
    }

    location = /404.html {
        internal;
    }       
}

If the above does not resolve your error, increase the verbosity of your error_log (e.g. to 'info') and see what page nginx is actually serving when you hit a 404.

Best Answer

Related Solutions

Nginx – Trouble with nginx and serving from multiple directories under the same domain

Nginx custom 404 error page for virtual host

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