How to use nginx modules
Like other web servers, nginx supports dynamically loaded modules to provide in-server support for programming languages, security mechanisms, and so on. Ubuntu provides a number of these modules as separate packages that are either installed simultaneously with nginx, or can be installed separately.
Available modules
nginx will report the modules it has been built with via its -V option. A quick and dirty way to list the available modules is thus:
$ nginx -V 2>&1 | tr -- - '\n' | grep _module
http_ssl_module
http_stub_status_module
http_realip_module
...
http_image_filter_module=dynamic
http_perl_module=dynamic
http_xslt_module=dynamic
stream_geoip_module=dynamic
Many of these modules are built-in and thus are always available with nginx, but some exist as separate packages whose installation status can be checked via apt. For example:
$ apt policy libnginx-mod-http-image-filter
libnginx-mod-http-image-filter:
Installed: (none)
Candidate: 1.24.0-1ubuntu1
Version table:
1.24.0-1ubuntu1 500
500 http://archive.ubuntu.com/ubuntu mantic/main amd64 Packages
apt can also be used to install the desired dynamic module:
$ sudo apt install libnginx-mod-http-image-filter
...
The following NEW packages will be installed:
libnginx-mod-http-image-filter
0 upgraded, 1 newly installed, 0 to remove and 34 not upgraded.
...
Triggering nginx reload
...
Enabling and disabling dynamic modules
Dynamic modules are automatically enabled and get reloaded by nginx on installation. If you need to manually disable an installed module, remove its file from the /etc/nginx/modules-enabled directory, for example:
$ ls /etc/nginx/modules-*
/etc/nginx/modules-available:
/etc/nginx/modules-enabled:
50-mod-http-image-filter.conf
$ sudo mv /etc/nginx/modules-enabled/50-mod-http-image-filter.conf /etc/nginx/modules-available/
$ service nginx restart
Note that built-in modules cannot be disabled/enabled.
Configuring modules
The installed configuration file for an nginx module mainly consists of the dynamically-loaded binary library:
## /etc/nginx/modules-enabled/50-mod-http-image-filter.conf
load_module modules/ngx_http_image_filter_module.so;
Note that you can also use the load_module parameter in your /etc/nginx/nginx.conf at the top level, if preferred for some reason.
To use a module for your website, its settings are specified in your server block. For example:
location /img/ {
image_filter resize 240 360;
image_filter rotate 180;
image_filter_buffer 16M;
error_page 415 = /415.html;
}
Further reading
You’ve completed the nginx guide! See the following resources for more in-depth information on further extending nginx’s capabilities:
-
The nginx documentation provides detailed explanations of configuration directives.
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O’Reilly’s nginx cookbook provides guidance on solving specific needs.
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For Ubuntu-specific nginx questions, ask in the
#ubuntu-serverIRC channel on libera.chat.