@longucodes/plugin-system-loader

Purpose

This package provides a Nestjs module for dynamically loading modules during runtime. The goal is to create a way of extending ready-to-go services without needing to edit their code.

Developer usage

To use the system, import the module in your application

import {Module} from "@nestjs/common";
import {PluginModule} from "@longucodes/plugin-system-loader";

@Module({
  imports: [
    PluginModule.forRoot({})
  ]
})
export class AppModule {}

Optionally, path to the definition file can be provided

import {Module} from "@nestjs/common";
import {PluginModule} from "@longucodes/plugin-system-loader";

@Module({
  imports: [
    PluginModule.forRoot({pluginsDefinitionFilePath: '/path/to/plugins.json'})
  ]
})
export class AppModule {}

It's recommended to use this module in conjunction with @longucodes/plugin-system-cli for runtime installation of plugins.

End-user usage

To add a plugin, add plugins.json file in the directory, where microservice is running and add plugin definitions. The file should consist of an array, with each entry representing one plugin.

Simple definition

Simples plugin definition is just the name of the NPM package

[
  "plugin-name"
]

The plugin will be automatically installed by the cli and loaded into the application.

Advanced definition

To add more capabilities, like config or specific version, advanced definition should be used.

[
  {
    "name": "plugin-name"
  }
]

In addition to name, following properties can be provided.

• version - install specific version of the package
• mode - can be static (default) and dynamic. Dynamic plugins will not be installed by cli
• config - object with configuration values

Config

The config object can contain direct values or read them from environment. To use environment variable , the config value should be the name of the environment variable with $ at the beginning. All variables consisting only of uppercase letters and _, and a $ will be treated as a environment variable read.

[
  {
    "name": "plugin-name",
    "config": {
      "staticVariable": "123",
      "dynamicVariable": "$SOME_VAR"
    }
  }
]

Not all plugins are configurable, check documentation of used plugin.

Plugin development

To create your own plugin, create NPM package, that default exports a Nestjs module. If you want your package to be configurable, add static method forRoot returning a dynamic module.