Project architecture

Nikita is a Node.js based software use to automate the execution of actions. Use an already defined action or write one in JavaScript. If you are interested to read the Nikita codebase, this page presents the high-level architecture of the project. Use it as a map to find what thing is doing what accross the code, where is it located.

Project layout

Nikita is organized as one GIT monorepo repository. If you are not familiar with this organization, read the Adaltas series of articles on monorepos in JavaScript.

All the packages are located inside the packages folder.

The documentation is located inside the docs/content folder for the raw documentation written in Markdown and the docs/website folder for the website generation with Gatsby.

Project management

Lerna is used to coordinate the installation of package and execution of commands accross all the Nikita packages.

Versioning and change log generation is based on conventionnal commit.

How packages relate to each other

The nikita package provide an entry point for the majority of users. The @nikitajs/core package is the heart of the library with its engine, the plugins and the core actions. All the other packages defines additionnal actions. For example, the @nikitajs/docker package defines Docker related actions.

The nikita package

Users are encouraged to declare the nikita package as their only dependency. The package is just a facade in front of the @nikitajs/core package where the Nikita logic resides and all the other packages which defines additional actions.

Using the nikita package, developers can require Nikita in their code with const nikita = require('nikita') and they are ready to go.

In fact, if you look inside the nikita package, there is only one module and its content is explicit:

// Register actions from Nikita packages
require('@nikitajs/db/lib/register')
require('@nikitajs/docker/lib/register')
require('@nikitajs/file/lib/register')
require('@nikitajs/ipa/lib/register')
require('@nikitajs/java/lib/register')
require('@nikitajs/krb5/lib/register')
require('@nikitajs/ldap/lib/register')
require('@nikitajs/log/lib/register')
require('@nikitajs/lxd/lib/register')
require('@nikitajs/network/lib/register')
require('@nikitajs/service/lib/register')
require('@nikitajs/system/lib/register')
require('@nikitajs/tools/lib/register')
// Expose the Nikita core engine
module.exports = require('@nikitajs/core')

The @nikitajs/core package

The package defines an entry point in the src/index.coffee module. The module creates a new session instance from the src/session.coffee module with all the plugins loaded.

Plugins are stored inside the src/plugins folder. Pretty much everything in Nikita is implemented as a plugin. Plugins define hooks which are interception points of the action lifecycle.

Worth of interest are also the src/registry.coffee module to register and unregister actions and the src/schedulers/native.coffee module to control the execution of action successive actions.