Plugins

BunkerWeb comes with a plugin system to make it possible to easily add new features. Once a plugin is installed, you can manage it using additional settings defined by the plugin.

Official plugins

Here is the list of "official" plugins that we maintain (see the bunkerweb-plugins repository for more information) :

Name	Version	Description	Link
ClamAV	0.1	Automatically scans uploaded files with the ClamAV antivirus engine and denies the request when a file is detected as malicious.	bunkerweb-plugins/clamav
CrowdSec	0.1	CrowdSec bouncer for BunkerWeb.	bunkerweb-plugins/crowdsec
VirusTotal	0.1	Automatically scans uploaded files with the VirusTotal API and denies the request when a file is detected as malicious.	bunkerweb-plugins/virustotal

How to use a plugin

The first step is to install the plugin by putting the plugin files inside the corresponding plugins data folder, the procedure depends on your integration :

DockerDocker autoconfSwarmKubernetesLinux

When using the Docker integration, plugins must be written to the volume mounted on /data.

The first thing to do is to create the plugins folder : shell mkdir -p ./bw-data/plugins

Then you can drop the plugins of your choice into that folder : shell git clone https://github.com/bunkerity/bunkerweb-plugins && \ cp -rp ./bunkerweb-plugins/* ./bw-data/plugins

Because BunkerWeb runs as an unprivileged user with UID and GID 101, you will need to edit the permissions : shell chown -R root:101 bw-data && \ chmod -R 770 bw-data

When starting the BunkerWeb container, you will need to mount the folder on /data : shell docker run \ ... -v "${PWD}/bw-data:/data" \ ... bunkerity/bunkerweb:1.4.0

Here is the docker-compose equivalent : yaml mybunker: image: bunkerity/bunkerweb:1.4.0 volumes: - ./bw-data:/data ...

When using the Docker autoconf integration, plugins must be written to the volume mounted on /data.

The easiest way to do it is by starting the Docker autoconf stack with a folder mounted on /data (instead of a named volume). Once the stack is started, you can copy the plugins of your choice to the plugins folder from your host : shell git clone https://github.com/bunkerity/bunkerweb-plugins && \ cp -rp ./bunkerweb-plugins/* ./bw-data/plugins

Because BunkerWeb runs as an unprivileged user with UID and GID 101, you will need to edit the permissions : shell chown -R root:101 bw-data && \ chmod -R 770 bw-data

When using the Swarm integration, the easiest way of installing plugins is by using docker exec and downloading the plugins from the container.

Execute a shell inside the autoconf container (use docker ps to get the name) : shell docker exec -it myautoconf /bin/bash

Once you have a shell inside the container, you can drop the plugins of your choice inside the /data/plugins folder : shell git clone https://github.com/bunkerity/bunkerweb-plugins && \ cp -rp ./bunkerweb-plugins/* /data/plugins

When using the Kubernetes integration, the easiest way of installing plugins is by using kubectl exec and downloading the plugins from the container.

Execute a shell inside the autoconf container (use kubectl get pods to get the name) : shell kubectl exec -it myautoconf -- /bin/bash

Once you have a shell inside the container, you can drop the plugins of your choice inside the /data/plugins folder : shell git clone https://github.com/bunkerity/bunkerweb-plugins && \ cp -rp ./bunkerweb-plugins/* /data/plugins

When using the Linux integration, plugins must be written to the /opt/bunkerweb/plugins folder : shell git clone https://github.com/bunkerity/bunkerweb-plugins && \ cp -rp ./bunkerweb-plugins/* /data/plugins

When a plugin is installed, you are ready to use it, please refer to the plugin documentation for more information.

Writing a plugin

Existing plugins

If the documentation is not enough you can have a look at the existing source code of official plugins and the core plugins (already included in BunkerWeb but they are plugins technically speaking).

The first step is to create a folder that will contain the plugin :

shell mkdir myplugin && \ cd myplugin

Metadata

A file named plugin.json and written at the root of the plugin folder must contain metadata about the plugin. Here is an example :

json { "id": "myplugin", "order": 42, "name": "My Plugin", "description": "Just an example plugin.", "version": "1.0", "settings": { "DUMMY_SETTING": { "context": "multisite", "default": "1234", "help": "Here is the help of the setting.", "id": "dummy-id", "label": "Dummy setting", "regex": "^.*$", "type": "text" } } "jobs": [ { "name": "my-job", "file": "my-job.py", "every": "hour" } ] }

Here are the details of the fields :

Field	Mandatory	Type	Description
`id`	yes	string	Internal ID for the plugin : must be unique among other plugins (including "core" ones) and contain only lowercase chars.
`order`	yes	int	When the plugin should be executed during the access phase : `1` for whitelisting, `2` for blacklisting, `3` for "standard security feature" or `999` if your settings don't use the access phase.
`name`	yes	string	Name of your plugin.
`description`	yes	string	Description of your plugin.
`version`	yes	string	Version of your plugin.
`settings`	yes	dict	List of the settings of your plugin.
`jobs`	no	list	List of the jobs of your plugin.

Each setting has the following fields (the key is the ID of the settings used in a configuration) :

Field	Mandatory	Type	Description
`context`	yes	string	Context of the setting : `multisite` or `global`.
`default`	yes	string	The default value of the setting.
`help`	yes	string	Help text about the plugin (shown in web UI).
`id`	yes	string	Internal ID used by the web UI for HTML elements.
`label`	yes	string	Label shown by the web UI.
`regex`	yes	string	The regex used to validate the value provided by the user.
`type`	yes	string	The type of the field : `text`, `check` or `select`.
`multiple`	no	string	Unique ID to group multiple settings with numbers as suffix.
`select`	no	list	List of possible string values when `type` is `select`.

Each job has the following fields :

Field	Mandatory	Type	Description
`name`	yes	string	Name of the job.
`file`	yes	string	Name of the file inside the jobs folder.
`every`	yes	string	Job scheduling frequency : `minute`, `hour`, `day`, `week` or `once` (no frequency, only once before (re)generating the configuration).

Configurations

You can add custom NGINX configurations by adding a folder named confs with content similar to the custom configurations. Each subfolder inside the confs will contain jinja2 templates that will be generated and loaded at the corresponding context (http, server-http and default-server-http).

Here is an example for a configuration template file inside the confs/server-http folder named example.conf :

conf location /setting { default_type 'text/plain'; content_by_lua_block { ngx.say('{{ DUMMY_SETTING }}') } }

{{ DUMMY_SETTING }} will be replaced by the value of the DUMMY_SETTING chosen by the user of the plugin.

LUA

Main script

Under the hood, BunkerWeb is using the NGINX LUA module to execute code within NGINX. Plugins that need to execute code must provide a lua file at the root directory of the plugin folder using the id value of plugin.json as its name. Here is an example named myplugin.lua :

```lua local _M = {} _M.__index = _M

local utils = require "utils" local datastore = require "datastore" local logger = require "logger"

function _M.new() local self = setmetatable({}, _M) self.dummy = "dummy" return self, nil end

function _M:init() logger.log(ngx.NOTICE, "MYPLUGIN", "init called") return true, "success" end

function _M:access() logger.log(ngx.NOTICE, "MYPLUGIN", "access called") return true, "success", nil, nil end

function _M:log() logger.log(ngx.NOTICE, "MYPLUGIN", "log called") return true, "success" end

return _M ```

The 3 functions init, access, and log are automatically called during specific contexts. Here are the details of each function :

Function	Context	Description	Return value
`init`	init_by_lua	Called when NGINX just started or received a reload order. the typical use case is to prepare any data that will be used by your plugin.	`ret`, `err` `ret` (boolean) : true if no error else false `err` (string) : success or error message
`access`	access_by_lua	Called on each request received by the server. The typical use case is to do the security checks here and deny the request if needed.	`ret`, `err`, `return`, `status` `ret` (boolean) : true if no error else false `err` (string) : success or error message `return` (boolean) : true if you want to stop the access phase and send a status to the client `status` (number) : the return value to set if `return` is set to true
`log`	log_by_lua	Called when a request has finished (and before it gets logged to the access logs). The typical use case is to make stats or compute counters for example.	`ret`, `err` `ret` (boolean) : true if no error else false `err` (string) : success or error message

Libraries

All directives from NGINX LUA module are available. On top of that, you can use the LUA libraries included within BunkerWeb : see this script for the complete list.

If you need additional libraries, you can put them in the root folder of the plugin and access them by prefixing them with your plugin ID. Here is an example file named mylibrary.lua :

```lua local _M = {}

_M.dummy = function () return "dummy" end

return _M ```

And here is how you can use it from the myplugin.lua file :

```lua local mylibrary = require "myplugin.mylibrary"

...

mylibrary.dummy()

... ```

Helpers

Some helpers modules provide common helpful functions :

datastore : access the global shared data (key/value store)
logger : generate logs
utils : various useful functions

To access the functions, you first need to require the module :

```lua ...

local utils = require "utils" local datastore = require "datastore" local logger = require "logger"

... ```

Retrieve a setting value :

lua local value, err = utils:get_variable("DUMMY_SETTING") if not value then logger.log(ngx.ERR, "MYPLUGIN", "can't retrieve setting DUMMY_SETTING : " .. err) else logger.log(ngx.NOTICE, "MYPLUGIN", "DUMMY_SETTING = " .. value) end

Store something in the cache :

lua local ok, err = datastore:set("plugin_myplugin_something", "somevalue") if not value then logger.log(ngx.ERR, "MYPLUGIN", "can't save plugin_myplugin_something into datastore : " .. err) else logger.log(ngx.NOTICE, "MYPLUGIN", "successfully saved plugin_myplugin_something into datastore into datastore") end

Check if an IP address is global :

lua local ret, err = utils.ip_is_global(ngx.var.remote_addr) if ret == nil then logger.log(ngx.ERR, "MYPLUGIN", "error while checking if IP " .. ngx.var.remote_addr .. " is global or not : " .. err) elseif not ret then logger.log(ngx.NOTICE, "MYPLUGIN", "IP " .. ngx.var.remote_addr .. " is not global") else logger.log(ngx.NOTICE, "MYPLUGIN", "IP " .. ngx.var.remote_addr .. " is global") end

More examples

If you want to see the full list of available functions, you can have a look at the files present in the lua directory of the repository.

Jobs

BunkerWeb uses an internal job scheduler for periodic tasks like renewing certificates with certbot, downloading blacklists, downloading MMDB files, ... You can add tasks of your choice by putting them inside a subfolder named jobs and listing them in the plugin.json metadata file. Don't forget to add the execution permissions for everyone to avoid any problems when a user is cloning and installing your plugin.