notification-service

notification-service

Overview

Microservice for handling notifications to users through real time notifications, email, or SMS.

Installation

npm i @sourceloop/notification-service

Implementation

Create a new Application using Loopback CLI and add the Component for NotificationService in application.ts

import {BootMixin} from '@loopback/boot';
import {ApplicationConfig} from '@loopback/core';
import {RepositoryMixin} from '@loopback/repository';
import {RestApplication} from '@loopback/rest';
import {
  RestExplorerBindings,
  RestExplorerComponent,
} from '@loopback/rest-explorer';
import {ServiceMixin} from '@loopback/service-proxy';
import { NotificationServiceComponent } from '@sourceloop/notification-service';
import * as dotenv from 'dotenv';
import * as dotenvExt from 'dotenv-extended';
import path from 'path';

export {ApplicationConfig};

const port = 3000;
export class Client extends BootMixin(
  ServiceMixin(RepositoryMixin(RestApplication)),
) {
  constructor(options: ApplicationConfig = {}) {
    dotenv.config();
    dotenvExt.load({
      schema: '.env.example',
      errorOnMissing: true,
      includeProcessEnv: true,
    });
    options.rest = options.rest || {};
    options.rest.port = +(process.env.PORT || port);
    options.rest.host = process.env.HOST;
    super(options);
    // Set up default home page
    this.static('/', path.join(__dirname, '../public'));

    // Customize @loopback/rest-explorer configuration here
    this.configure(RestExplorerBindings.COMPONENT).to({
      path: '/explorer',
    });
    this.component(RestExplorerComponent);
    // add Component for NotificationService
    this.component(NotificationServiceComponent);

    this.projectRoot = __dirname;
    // Customize @loopback/boot Booter Conventions here
    this.bootOptions = {
      controllers: {
        // Customize ControllerBooter Conventions here
        dirs: ['controllers'],
        extensions: ['.controller.js'],
        nested: true,
      },
    };
  }
}

Environment Variables

Name	Required	Default Value	Description
NODE_ENV	Y		Node environment value, i.e. dev, test, prod
LOG_LEVEL	Y		Log level value, i.e. error, warn, info, verbose, debug
DB_HOST	Y		Hostname for the database server.
DB_PORT	Y		Port for the database server.
DB_USER	Y		User for the database.
DB_PASSWORD	Y		Password for the database user.
DB_DATABASE	Y		Database to connect to on the database server.
DB_SCHEMA	Y		Database schema used for the data source. In PostgreSQL, this will be public unless a schema is made explicitly for the service.
JWT_SECRET	Y		Symmetric signing key of the JWT token.
JWT_ISSUER	Y		Issuer of the JWT token.

Setting up DataSource

Here is a sample Implementation DataSource implementation using environment variables and PostgreSQL as the data source.

import {inject, lifeCycleObserver, LifeCycleObserver} from '@loopback/core';
import {juggler} from '@loopback/repository';

const config = {
  name: 'notificationDb',
  connector: 'postgresql',
  url: '',
  host: process.env.DB_HOST,
  port: process.env.DB_PORT,
  user: process.env.DB_USER,
  password: process.env.DB_PASSWORD,
  database: process.env.DB_DATABASE,
  schema: process.env.DB_SCHEMA,
};

@lifeCycleObserver('datasource')
export class NotificationDbDataSource extends juggler.DataSource
  implements LifeCycleObserver {
  static dataSourceName = 'notification';
  static readonly defaultConfig = config;

  constructor(
    // You need to set datasource configuration name as 'datasources.config.Notification' otherwise you might get Errors
    @inject('datasources.config.Notification', {optional: true})
    dsConfig: object = config,
  ) {
    super(dsConfig);
  }
}

Migrations

Refer to Database Migrations | LoopBack Documentation for instructions for handling migrations.

API Documentation

Common Headers

Authorization: Bearer where is a JWT token signed using JWT issuer and secret. Content-Type: application/json in the response and in request if the API method is NOT GET

Common Request path Parameters

{version}: Defines the API Version

Common Responses

200: Successful Response. Response body varies w.r.t API
401: Unauthorized: The JWT token is missing or invalid
403: Forbidden : Not allowed to execute the concerned API
404: Entity Not Found
400: Bad Request (Error message varies w.r.t API)
201: No content: Empty Response

API Details