ng-config

Configuration library for Angular handling environments in continuous delivery systems.

Why using ng-config?

Angular comes with built-in mechanism of environment files but this mechanism requires you to build for each environment. This approach doesn't fit to modern development paradigm which advocate for build once - deploy anywhere.

Getting started

Installation

npm install @golavr/ng-config --save

Create files

1. Create assets/configs folder.
2. Create assets/configs/env.json file.
3. Create assets/configs/config.json file.
4. Create assets/configs/config.prod.json file.
5. Add more assets/configs/config.$$$.json files to support all environments.

You should have this folder structure:

- assets
    - configs
        - config.json
        - config.prod.json
        - env.json

Note: Library depends on the above folder and file names.

env.json file

Open assets/configs/env.json and add this content:

{
  "env": "prod"
}

In continues delivery system you should edit the env value to target the selected environment.

Note: you can replace prod with other environment $$$ as long as you have assets/configs/config.$$$.json file for it.

How to use?

Lets set two configuration values for demonstration purpose.

Open assets/configs/config.json file and add:

{
    "baseValue": "other configurations will inherit this value",
    "overrideValue": "base"
}

Open assets/configs/config.prod.json file and add:

{
    "overrideValue": "prod"
}

Create interface reflecting the configuration:

export interface MyConfig {
  baseValue: string;
  overrideValue: string;
}

Inject it and use it:

import { Component } from '@angular/core';
import { ConfigService } from 'ng-config';
import { MyConfig } from './my-config';

@Component({
  selector: 'app-root',
  templateUrl: './app.component.html',
  styleUrls: ['./app.component.css']
})
export class AppComponent {
  constructor(config: ConfigService) {
    config.get<MyConfig>().subscribe(conf => console.log(conf.overrideValue));
  }
}

How does it work?

Each request will read config values during the call, so changes can be made to config files while the app is running. The returned config object will be composed from config.json and will be overridden with env config. In continues delivery system you need to edit env.json and set which env config (config.prod.json) will be selected at runtime. You can have multiple env config files like config.integration.json etc.