Simple Chat service using Hexagonal Architecture with Go

• Install Golang
• Install tflocal
• Install Docker or Podman
• Install Docker Compose
• Install AWS CLI
• Install GolangCI Linter
• Install gomock

Short version if you have all the tools installed and configured (never happens :) ) (it will start a local web page http://localhost:8081 that you can connect to play with chat)

make setup

Create containers to run the service with docker compose

make infra-up

Run local infra setup - executes terraform code against LocalStack

make infra-local #

Executes tests and creates coverage report against local infra

make cover

• Handler: http with WebSocket
• Repository: DynamoDB
• Notifier: RabbitMQ
• Moderator: Ignore (just passthrough the message, no moderation done)

sequenceDiagram 
    title: Connect Flow
    Client -->> WebSocket: Connect(uID, roomID)
    WebSocket -->> ChatService: Register(uID, roomID)
    ChatService -->> Notifier: Register(uID, roomID, receiver)
    Notifier ->> ChatService: Registered 
    ChatService --> WebSocket: Registered
    WebSocket -> Client: Connected 

sequenceDiagram 
    title: Send Message Flow
    Client -->> WebSocket: Send(message, roomID)
    WebSocket -->> ChatService: Send(message, roomID)    
    ChatService -->> Moderator: Check(message)
    Moderator ->> ChatService: ModeratedMessage
    ChatService -->> Repository: Store(ModeratedMessage)
    Repository ->> ChatService: ModeratedMessageStored
    ChatService -->> Notifier: Broadcast(ModeratedMessage, GroupId)
    Notifier ->> ChatService: Sent OK
    ChatService ->> WebSocket: Sent
    WebSocket ->> Client: Sent

• Implement a Presence component that embeds the notification system
• Integrate a mock framework (gomock)
• Add logging
• Integrate Golang Linters
• Implement WebSocket Handler
• Add Grafana, Prometheus to Docker Compose
• Separated UnitTest from Integration Tests (with local infra)
• Improve tests that cover errors
• Add CICD with Github Actions
• Add Configuration (Consul, Vault)
• Add metricts
• Add rate limiting
• Add Load Tests Local
• Add Load Tests Cloud
• Add deployment on ECS
• Add deployment on K8S
• Add deployment on Nomad
• Explore coverage report in Github [https://github.com/johejo/go-cover-view]

• - Remove dependency of AWS CLI by running in a container