# Plugins¶

Bunkerized-nginx comes with a plugin system that lets you extend the core with extra security features.

## Official plugins¶

• ClamAV : automatically scan uploaded files and deny access if a virus is detected

• CrowdSec : CrowdSec bouncer integration within bunkerized-nginx

## Community plugins¶

If you have made a plugin and want it to be listed here, feel free to create a pull request and edit that section.

## Use a plugin¶

The generic way of using a plugin consists of :

• Edit the settings inside the plugin.json files (e.g., myplugin/plugin.json)

• If you are using a container based integration, you need to mount it to the plugins special folder inside the container (e.g., /where/is/myplugin:/plugins/myplugin)

• If you are using Linux integration, copy the downloaded plugin folder to the plugins special folder (e.g., cp -r myplugin /plugins)

To check if the plugin is loaded you should see log entries like that :

2021/06/05 09:19:47 [error] 104#104: [PLUGINS] *NOT AN ERROR* plugin MyPlugin/1.0 has been loaded


## Write a plugin¶

A plugin is composed of a plugin.json which contains metadata (e.g. : name, settings, …) and a set of LUA files for the plugin code.

### plugin.json¶

{
"id": "myplugin",
"name": "My Plugin",
"description": "Short description of my plugin.",
"version": "1.0",
"settings": {
"MY_SETTING": "value1",
"ANOTHER_SETTING": "value2",
}
}


The id value is really important because it must match the subfolder name inside the plugins volume. Choose one which isn’t already used to avoid conflicts.

Settings names and default values can be choosen freely. There will be no conflict when you retrieve them because they will be prefixed with your plugin id (e.g. : myplugin_MY_SETTING).

### Main code¶

local M		= {}
local logger	= require "logger"

-- this function will be called at startup
-- the name MUST be init without any argument
function M.init ()
-- the logger.log function lets you write into the logs
-- only ERROR level is available in init()
logger.log(ngx.ERR, "MyPlugin", "*NOT AN ERROR* init called")

-- here is how to retrieve a setting
local my_setting = ngx.shared.plugins_data:get("pluginid_MY_SETTING")
logger.log(ngx.ERR, "MyPlugin", "*NOT AN ERROR* my_setting = " .. my_setting)

return true
end

-- this function will be called for each request
-- the name MUST be check without any argument
function M.check ()

-- the logger.log function lets you write into the logs
logger.log(ngx.NOTICE, "MyPlugin", "check called")

-- here is how to retrieve a setting
local my_setting = ngx.shared.plugins_data:get("pluginid_MY_SETTING")

-- a dummy example to show how to block a request
if my_setting == "block" then
ngx.exit(ngx.HTTP_FORBIDDEN)
end
end

return M


That file must have the same name as the id defined in the plugin.json with a .lua suffix (e.g. : myplugin.lua).

Under the hood, bunkerized-nginx uses the lua nginx module therefore you should be able to access to the whole ngx.* functions.

### Dependencies¶

Since the core already uses some external libraries you can use it in your own plugins too (see the compile.sh file and the core lua files).

In case you need to add dependencies, you can do it by placing the corresponding files into the same folder of your main plugin code. Here is an example with a file named dependency.lua :

local M = {}

function M.my_function ()
return "42"
end

return M


To include it from you main code you will need to prefix it with your plugin id like that :

...
local my_dependency = require "pluginid.dependency"

function M.check ()
...
local my_value = my_dependency.my_function()
...
end
...