Email-System

System that handles a large number of email requests

Design diagram for the system

To be added here

Link: https://github.com/sunil-karki/Email-System/blob/main/Design_diagram.png

Starting the Services for Email System

This guide will walk you through the process of starting three services in Python: a producer service, a consumer service, and Kafka servers. These services will communicate with each other using Apache Kafka as the messaging system.

Prerequisites

Before you start, ensure that you have the following installed on your system, except MongoDB:

Python (version 3.9.7 or higher)
Kafka (version __ or higher)
Flask (version __ or higher)
MongoDB

Steps To Follow

Follow these steps to start the three services:

Start Kafka

Start your Kafka server by running the appropriate command based on your installation. This typically involves starting the ZooKeeper server and then starting the Kafka broker. You can refer to the Kafka documentation for detailed setup.

After the setup, start the ZooKeeper for Kafka
```
.\bin\windows\zookeeper-server-start.bat .\config\zookeeper.properties
```
Start the Kafka broker
```
.\bin\windows\kafka-server-start.bat .\config\server.properties
```
Set Up MongoDB Database

In your preferred terminal or command prompt:
```
docker pull mongo
```
This will pull image file of the MongoDB database

Then, run the container (27017 is port for MongoDB)
```
docker run --name mongodb -d -p 27017:27017 mongo
```
Start the Consumer Service

Run the following command to start the EmailService (consumer 1): (You can skip this if to run in Docker)
```
python kafkaServerService.py
```
Run the following command to start the next consumer service (consumer 2): (You can skip this if to run in Docker)
```
python kafkaDBService.py
```
To run it on Docker, execute the following four commands below:
Note: In files 'serverServiceDockerfile' and 'dbServiceDockerfile', add IP address/port where kafka server runs and also IP address/port for MongoDB. IP address could be found with ipconfig or ifconfig.

For EmailService (consumer 1):
```
docker build -t email-service -f serverServiceDockerfile .
```
```
docker run --name email-service-container2 -d email-service
```
Then, for DBService (consumer 2):
```
docker build -t db-service -f dbServiceDockerfile .
```
```
docker run --name db-service-container3 -d db-service
```
Start the Producer Service

Run the following command to start the ApiGateway service (producer): (You can skip this if to run in Docker)
```
python apiGateway.py
```
To run it on Docker, execute the following two commands:
Note: In apiGatewayDockerfile, add IP address/port where kafka server runs.
```
docker build -t api-gateway -f apiGatewayDockerfile .
```
Then,
```
docker run --name api-gateway-container -d -p 8000:8000 api-gateway
```

Interact with the Services

Run the following command to send the email:

curl --header "Content-Type: application/json" --request POST --data "{\"emailFrom\": \"tese320@gmail.com\", \"emailTo\": \"test1@gmail.com\", \"message\": \"Message from gateway\", \"subject\": \"apigateway.\", \"templateFlag\": \"1\"}"  http://localhost:8000/sendMail

Run the following command to query the email records/documents:

curl --header "Content-Type: application/json" --request POST --data "{\"emailAddress\": \"tese320@gmail.com\", \"startTime\": \"2022-08-15\", \"endTime\": \"2022-10-15\"}" http://localhost:8000/queryMail