netbox/docs/plugins/development/index.md

Plugins Development

!!! tip "Plugins Development Tutorial" Just getting started with plugins? Check out our NetBox Plugin Tutorial on GitHub! This in-depth guide will walk you through the process of creating an entire plugin from scratch. It even includes a companion demo plugin repo to ensure you can jump in at any step along the way. This will get you up and running with plugins in no time!

!!! tip "Plugin Certification Program" NetBox Labs offers a Plugin Certification Program for plugin developers interested in establishing a co-maintainer relationship. The program aims to assure ongoing compatibility, maintainability, and commercial supportability of key plugins.

NetBox can be extended to support additional data models and functionality through the use of plugins. A plugin is essentially a self-contained Django app which gets installed alongside NetBox to provide custom functionality. Multiple plugins can be installed in a single NetBox instance, and each plugin can be enabled and configured independently.

!!! info "Django Development" Django is the Python framework on which NetBox is built. As Django itself is very well-documented, this documentation covers only the aspects of plugin development which are unique to NetBox.

Plugins can do a lot, including:

• Create Django models to store data in the database
• Provide their own "pages" (views) in the web user interface
• Inject template content and navigation links
• Extend NetBox's REST and GraphQL APIs
• Load additional Django apps
• Add custom request/response middleware

However, keep in mind that each piece of functionality is entirely optional. For example, if your plugin merely adds a piece of middleware or an API endpoint for existing data, there's no need to define any new models.

!!! warning While very powerful, the NetBox plugins API is necessarily limited in its scope. The plugins API is discussed here in its entirety: Any part of the NetBox code base not documented here is not part of the supported plugins API, and should not be employed by a plugin. Internal elements of NetBox are subject to change at any time and without warning. Plugin authors are strongly encouraged to develop plugins using only the officially supported components discussed here and those provided by the underlying Django framework to avoid breaking changes in future releases.

Plugin Structure

Although the specific structure of a plugin is largely left to the discretion of its authors, a typical NetBox plugin might look something like this:

project-name/
  - plugin_name/
    - api/
      - __init__.py
      - serializers.py
      - urls.py
      - views.py
    - migrations/
      - __init__.py
      - 0001_initial.py
      - ...
    - templates/
      - plugin_name/
        - *.html
    - __init__.py
    - filtersets.py
    - graphql.py
    - jobs.py
    - models.py
    - middleware.py
    - navigation.py
    - signals.py
    - tables.py
    - template_content.py
    - urls.py
    - views.py
  - pyproject.toml
  - README.md

The top level is the project root, which can have any name that you like. Immediately within the root should exist several items:

• pyproject.toml - is a standard configuration file used to install the plugin package within the Python environment.
• README.md - A brief introduction to your plugin, how to install and configure it, where to find help, and any other pertinent information. It is recommended to write README files using a markup language such as Markdown to enable human-friendly display.
• The plugin source directory. This must be a valid Python package name, typically comprising only lowercase letters, numbers, and underscores.

The plugin source directory contains all the actual Python code and other resources used by your plugin. Its structure is left to the author's discretion, however it is recommended to follow best practices as outlined in the Django documentation. At a minimum, this directory must contain an __init__.py file containing an instance of NetBox's PluginConfig class, discussed below.

Note: The Cookiecutter NetBox Plugin can be used to auto-generate all the needed directories and files for a new plugin.

PluginConfig

The PluginConfig class is a NetBox-specific wrapper around Django's built-in AppConfig class. It is used to declare NetBox plugin functionality within a Python package. Each plugin should provide its own subclass, defining its name, metadata, and default and required configuration parameters. An example is below:

from netbox.plugins import PluginConfig

class FooBarConfig(PluginConfig):
    name = 'foo_bar'
    verbose_name = 'Foo Bar'
    description = 'An example NetBox plugin'
    version = '0.1'
    author = 'Jeremy Stretch'
    author_email = 'author@example.com'
    base_url = 'foo-bar'
    required_settings = []
    default_settings = {
        'baz': True
    }
    django_apps = ["foo", "bar", "baz"]

config = FooBarConfig

NetBox looks for the config variable within a plugin's __init__.py to load its configuration. Typically, this will be set to the PluginConfig subclass, but you may wish to dynamically generate a PluginConfig class based on environment variables or other factors.

PluginConfig Attributes

Name	Description
name	Raw plugin name; same as the plugin's source directory
verbose_name	Human-friendly name for the plugin
version	Current release (semantic versioning is encouraged)
description	Brief description of the plugin's purpose
author	Name of plugin's author
author_email	Author's public email address
base_url	Base path to use for plugin URLs (optional). If not specified, the project's name will be used.
required_settings	A list of any configuration parameters that must be defined by the user
default_settings	A dictionary of configuration parameters and their default values
django_apps	A list of additional Django apps to load alongside the plugin
min_version	Minimum version of NetBox with which the plugin is compatible
max_version	Maximum version of NetBox with which the plugin is compatible
middleware	A list of middleware classes to append after NetBox's build-in middleware
queues	A list of custom background task queues to create
search_extensions	The dotted path to the list of search index classes (default: search.indexes)
data_backends	The dotted path to the list of data source backend classes (default: data_backends.backends)
template_extensions	The dotted path to the list of template extension classes (default: template_content.template_extensions)
menu_items	The dotted path to the list of menu items provided by the plugin (default: navigation.menu_items)
graphql_schema	The dotted path to the plugin's GraphQL schema class, if any (default: graphql.schema)
user_preferences	The dotted path to the dictionary mapping of user preferences defined by the plugin (default: preferences.preferences)

All required settings must be configured by the user. If a configuration parameter is listed in both required_settings and default_settings, the default setting will be ignored.

!!! tip "Accessing Config Parameters" Plugin configuration parameters can be accessed using the get_plugin_config() function. For example:

```python
from netbox.plugins import get_plugin_config
get_plugin_config('my_plugin', 'verbose_name')
```

Important Notes About django_apps

Loading additional apps may cause more harm than good and could make identifying problems within NetBox itself more difficult. The django_apps attribute is intended only for advanced use cases that require a deeper Django integration.

Apps from this list are inserted before the plugin's PluginConfig in the order defined. Adding the plugin's PluginConfig module to this list changes this behavior and allows for apps to be loaded after the plugin.

Any additional apps must be installed within the same Python environment as NetBox or ImproperlyConfigured exceptions will be raised when loading the plugin.

Create pyproject.toml

pyproject.toml is the configuration file used to package and install our plugin once it's finished. It is used by packaging tools, as well as other tools. The primary function of this file is to call the build system to create a Python distribution package. We can pass a number of keyword arguments to control the package creation as well as to provide metadata about the plugin. There are three possible TOML tables in this file:

• [build-system] allows you to declare which build backend you use and which other dependencies (if any) are needed to build your project.
• [project] is the format that most build backends use to specify your project’s basic metadata, such as the author's name, project URL, etc.
• [tool] has tool-specific subtables, e.g., [tool.black], [tool.mypy]. Consult the particular tool’s documentation for reference.

An example pyproject.toml is below:

# See PEP 518 for the spec of this file
# https://www.python.org/dev/peps/pep-0518/

[build-system]
requires = ["setuptools"]
build-backend = "setuptools.build_meta"

[project]
name =  "my-example-plugin"
version = "0.1.0"
authors = [
    {name = "John Doe", email = "test@netboxlabs.com"},
]
description = "An example NetBox plugin."
readme = "README.md"

classifiers=[
    'Development Status :: 3 - Alpha',
    'Intended Audience :: Developers',
    'Natural Language :: English',
    "Programming Language :: Python :: 3 :: Only",
    'Programming Language :: Python :: 3.10',
    'Programming Language :: Python :: 3.11',
    'Programming Language :: Python :: 3.12',
]

requires-python = ">=3.10.0"

Many of these are self-explanatory, but for more information, see the pyproject.toml documentation.

Create a Virtual Environment

It is strongly recommended to create a Python virtual environment for the development of your plugin, as opposed to using system-wide packages. This will afford you complete control over the installed versions of all dependencies and avoid conflict with system packages. This environment can live wherever you'd like, however it should be excluded from revision control. (A popular convention is to keep all virtual environments in the user's home directory, e.g. ~/.virtualenvs/.)

python3 -m venv ~/.virtualenvs/my_plugin

You can make NetBox available within this environment by creating a path file pointing to its location. This will add NetBox to the Python path upon activation. (Be sure to adjust the command below to specify your actual virtual environment path, Python version, and NetBox installation.)

echo /opt/netbox/netbox > $VENV/lib/python3.10/site-packages/netbox.pth

Development Installation

To ease development, it is recommended to go ahead and install the plugin at this point using setuptools' develop mode. This will create symbolic links within your Python environment to the plugin development directory. Call pip from the plugin's root directory with the -e flag:

$ pip install -e .

More information on editable builds can be found at Editable installs for pyproject.toml .

Configure NetBox

To enable the plugin in NetBox, add it to the PLUGINS parameter in configuration.py:

PLUGINS = [
    'my_plugin',
]