Go Random Chat (Kafka version)

Modern real-time random chat with high performance and linear scalability, written in go.

Features:

• Real-time communication and efficient websocket handling using Melody.
• Microservices architecture. All services can be horizontally scaled on demand.
  • web: frontend server
  • user: user account server
  • match: user matching server
  • chat: messaging server
  • uploader: file uploader
• Use gRPC for inter-service communication
  • with retry, timeout, rate limiting, and circuit breaker
• Use cobra and viper for CLI and configuration management respectively.
• Dependency injection using wire.
• Observability using client_golang and opentelemetry-go.
• At-least-once delivery for message Pub/Sub using Kafka.
• Persist messages and channel metadata in Cassandra, an open source NoSQL distributed database trusted by thousands of companies for scalability and high availability.
• Use Traefik FowardAuth for authentication when uploading files.
• Automatically generate RESTful API documentation with Swagger 2.0.
• User matching with idempotency.
• Message seen feature.
• Auto-scroll to the first unseen message.
• Automatic websocket reconnection.
• File uploads using object storage.
• Responsive web design.

System architecture:

Usage

Prerequisite:

• Docker-Compose v2
• Root permission

To run locally, execute the following command:

cd deployments
docker-compose up cassandra -d
# check cassandra connection
docker exec deployments-cassandra-1 bash -c "cqlsh -u ming -p cassandrapass"
# once cassandra starts successfully
sudo ./run.sh start

run.sh needs root permission to alias minio to localhost in /etc/hosts.

This will spin up all services declared in docker-compose.yaml. Visit http://localhost and you will see the application home page.

Bucket myfilebucket will be created automatically on minio by createbucket. However, if minio is still initializing after 5 retries of createbucket, the bucket creation will fail. If this happens, please run the following command once minio is up and running:

docker restart deployments-createbucket-1

• Visit http://localhost for the application home page.
• Visit http://localhost:8080 for Traefik dashboard.
• VIsit http://localhost:9000 for Minio dashboard.
• Visit http://localhost:9090 for Prometheus dashboard.
• Visit http://localhost:16686 for Jaeger dashboard.
• Visit http://localhost/api/<svc>/swagger/index.html for API documentation, where <svc> could be user, match, chat, or uploader.

Example configuration: config.example.yaml.

Deploy with SSL

A common scenario is that one deploys the application behind a reverse proxy with SSL termination. If that is your case, remember to correctly configure your proxy for websocket. For example, in Google Cloud Platform, for websocket traffic sent through a Google Cloud external HTTP(S) load balancer, the backend service timeout is interpreted as the maximum amount of time that a WebSocket connection can remain open, whether idle or not. Therefore, you may want to use a timeoutSec value larger than the default 30 seconds in your BackendConfig.

Docker Tagging Rules

Event	Ref	Docker Tags
pull_request	refs/pull/2/merge	pr-2
push	refs/heads/master	master
push	refs/heads/releases/v1	releases-v1
push tag	refs/tags/v1.2.3	v1.2.3, latest
push tag	refs/tags/v2.0.8-beta.67	v2.0.8-beta.67, latest

Screenshots