Backend Instant Messaging System

This is a server assignment for Tiktok Tech Immersion 2023

Table of Contents

1. About The Project
   • Built With
   • Kitex
   • Hertz
2. Getting Started
   • Prerequisites
   • Running using Kubernetes
   • Running using Docker Compose
   • Result
3. API Documentation

About The Project

This assignment is about designing and developing an IM system by implementing a set of specific APIs using Golang. This project only contains the backend side of the system, focusing on core message features without the front-end part and the account/authentication part.

It has two main features:

• Sender can send a message to a receiver, and message will be stored in the database
• Receiver can retrieve all messages sent to him/her through pull mocde

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Built With

This project is built with the following tools:

• Golang
• Kitex
• Hertz
• Redis
• Docker
• Kubernetes

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Kitex

• kitex_gen folder includes codes generated from idl_rpc.thrift. This generates RPC client code to be used in both HTTP Server and RPC Server
• If the definitions of idl_rpc.thrift file is modified, remember to regenerate the codes
• Install thrift compiler

  go install github.com/cloudwego/thriftgo
  

• Install Kitex

  go install github.com/cloudwego/kitex/tool/cmd/kitex@latest
  

• Generate the code for both http-server and rpc-server

  cd ./rpc-server
  kitex -module "github.com/ernst12/Backend_Server-TikTok_Tech_Immersion-Assignment/rpc-server" -service imservice ../idl_rpc.thrift
  cp -r ./kitex_gen ../http-server
  

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Hertx

• If you wish to modify the API definitions, remember to update idl_http.proto file and regenerate the code
• To regenerate the code:
• Install Protobuf (for MacOS)

  brew install protobuf
  

• Install protoc-gen-go plugin to generate idl code

  go install github.com/golang/protobuf/protoc-gen-go@latest
  

• Generate the new API definitions

  protoc --go_out=./http-server/proto_gen/api --go_opt=paths=source_relative ./idl_http.proto`
  

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Getting Started

To get a local copy up and running follow these simple example steps.

Prerequisites

Clone the repo into your local machine

gh repo clone Jaylin0312/TikTokImmersion_Assignment

Running using Kubernetes

1. Build the docker images for both http-server and rpc-server

cd ./http-server
docker build -t http-server .
cd ../rpc-server
docker build -t rpc-server .

2. Publish the images to Docker Hub

docker tag http-server [your docker username]/http-server
docker push [your docker username]/http-server
docker tag rpc-server [your docker username]/rpc-server
docker push [your docker username]/rpc-server

3. Deploy the images to Kubernetes

kubectl apply -f ./k8

Extra notes: Check the status of the pods

kubectl get pods

Check the status of the services

kubectl get services

If you want to delete the services and deployments created (after running the above command), you can run the following commands:

kubectl delete -f ./k8

Running using Docker Compose

1. Run the following command to start the containers

docker-compose up

2. To stop the containers, run the following command

docker-compose down

Result

You should now be able to access and test the APIs through the following endpoints using Postman or similar tool:

• http://localhost:8080/send
• http://localhost:8080/pull

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API Documentation

Send Message

1. Send message to receiver

• Endpoint: http://localhost:8080/send
• Method: POST
• Sample Request Body:

{
  "chat": "user1:user2",
  "text": "hello world!",
  "sender": "user1"
}

2. You should be able to see the status code 200 OK

Pull Message

1. Pull message from redis database

• Endpoint: http://localhost:8080/pull
• Method: GET
• Sample Request Body:

{
  "chat": "user1:user2",
  "limit": 10,
  "cursor": 0,
  "reverse": true
}

2. You should be able to see the status code 200 OK and the following response body:

{
  "messages": [
    {
      "chat": "user1:user2",
      "text": "hello world!",
      "sender": "user1",
      "send_time": 1686674603
    }
  ]
}