From 698928847181fc5ad0073696ebe34dd017daaad4 Mon Sep 17 00:00:00 2001
From: Kfir Dayan <kfda89@gmail.com>
Date: Sun, 9 Jul 2023 00:28:31 +0300
Subject: [PATCH] env vars from singleton service class

---
 .../src/controllers/todoController.ts         |  3 ---
 todo-service/src/main.ts                      | 10 ++++----
 .../src/middleware/createTodoMiddleWare.ts    |  1 -
 todo-service/src/rabbitmq/RabbitMQ.ts         | 15 +++++------
 todo-service/src/services/EnvService.ts       | 25 +++++++++++++++++++
 5 files changed, 38 insertions(+), 16 deletions(-)
 create mode 100644 todo-service/src/services/EnvService.ts

diff --git a/todo-service/src/controllers/todoController.ts b/todo-service/src/controllers/todoController.ts
index 6744bab..8dc8dab 100644
--- a/todo-service/src/controllers/todoController.ts
+++ b/todo-service/src/controllers/todoController.ts
@@ -2,11 +2,8 @@ import { NextFunction, Request, Response } from "express";
 import { ApiError } from "../utils/ApiError";
 import { ITodo } from "../schemas/todoSchema";
 import { TodoModel } from "../models/todoModel";
-// import { Sqs } from '../aws/Sqs';
 import { RabbitMQ } from "../rabbitmq/RabbitMQ";
 
-const env = require("dotenv").config().parsed;
-
 export class TodoController {
   private todoModel: TodoModel;
   queue: RabbitMQ;
diff --git a/todo-service/src/main.ts b/todo-service/src/main.ts
index e357fde..17ff8ef 100644
--- a/todo-service/src/main.ts
+++ b/todo-service/src/main.ts
@@ -1,15 +1,15 @@
 import express from "express";
 import mongoose from "mongoose";
 import todoRouter from "./routes/todoRouter";
-
+import { EnvService } from "./services/EnvService";
 import { ApiError } from "./utils/ApiError";
 
-const env = require("dotenv").config().parsed;
-
 class TodoApp {
   app: express.Application;
+  envService: EnvService;
 
   constructor() {
+    this.envService = EnvService.getInstance();
     this.connectToDB();
   }
 
@@ -29,7 +29,7 @@ class TodoApp {
   }
 
   private startServer() {
-    const PORT = env.PORT || 3000;
+    const PORT = this.envService.getEnvVariable("PORT") || 3000;
     this.app.listen(PORT, () => {
       console.log(`Server started on port ${PORT}`);
     });
@@ -40,7 +40,7 @@ class TodoApp {
   }
 
   private connectToDB() {
-    mongoose.connect(env.DATABASE_URL);
+    mongoose.connect(this.envService.getEnvVariable("DATABASE_URL"));
     const db = mongoose.connection;
     // Check for DB connection
     db.on("error", () => {
diff --git a/todo-service/src/middleware/createTodoMiddleWare.ts b/todo-service/src/middleware/createTodoMiddleWare.ts
index fd733cb..d48bb3c 100644
--- a/todo-service/src/middleware/createTodoMiddleWare.ts
+++ b/todo-service/src/middleware/createTodoMiddleWare.ts
@@ -1,7 +1,6 @@
 import { Request, Response, NextFunction } from "express";
 import { ApiError } from "../utils/ApiError";
 import { DateTime } from "luxon";
-import moment from "moment-timezone";
 
 const createTodoMiddleWare = async (
   req: Request,
diff --git a/todo-service/src/rabbitmq/RabbitMQ.ts b/todo-service/src/rabbitmq/RabbitMQ.ts
index 0333ea0..9ce035b 100644
--- a/todo-service/src/rabbitmq/RabbitMQ.ts
+++ b/todo-service/src/rabbitmq/RabbitMQ.ts
@@ -1,16 +1,17 @@
 import amqp, { Options, ConsumeMessage, Channel } from "amqplib";
 import { ITodo } from "../schemas/todoSchema";
-
-const env = require("dotenv").config().parsed;
+import { EnvService } from "../services/EnvService";
 
 export class RabbitMQ {
   connection: amqp.Connection;
   channel: amqp.Channel;
   queue: string;
   exchange: string;
+  envService: EnvService;
 
   constructor() {
-    this.queue = env.RABBITMQ_QUEUE_NAME;
+    this.envService = EnvService.getInstance();
+    this.queue = this.envService.getEnvVariable("RABBITMQ_QUEUE_NAME");
     this.exchange = "delayed_exchange";
 
     this.connect()
@@ -26,10 +27,10 @@ export class RabbitMQ {
     try {
       this.connection = await amqp.connect({
         protocol: "amqp",
-        hostname: env.RABBITMQ_HOST,
-        port: parseInt(env.RABBITMQ_PORT),
-        username: env.RABBITMQ_USERNAME,
-        password: env.RABBITMQ_PASSWORD,
+        hostname: this.envService.getEnvVariable("RABBITMQ_HOST"),
+        port: parseInt(this.envService.getEnvVariable('RABBITMQ_PORT')),
+        username: this.envService.getEnvVariable('RABBITMQ_USERNAME'),
+        password: this.envService.getEnvVariable('RABBITMQ_PASSWORD'),
       });
 
       this.channel = await this.connection.createChannel();
diff --git a/todo-service/src/services/EnvService.ts b/todo-service/src/services/EnvService.ts
new file mode 100644
index 0000000..5c7ccea
--- /dev/null
+++ b/todo-service/src/services/EnvService.ts
@@ -0,0 +1,25 @@
+import dotenv from "dotenv";
+
+// Load environment variables from .env file
+dotenv.config();
+
+export class EnvService {
+  private static instance: EnvService;
+  private env: any;
+
+  private constructor() {
+    // Get the parsed environment variables
+    this.env = dotenv.config().parsed;
+  }
+
+  public static getInstance(): EnvService {
+    if (!EnvService.instance) {
+      EnvService.instance = new EnvService();
+    }
+    return EnvService.instance;
+  }
+
+  public getEnvVariable(name: string): string | undefined {
+    return this.env[name];
+  }
+}