Newsfeed

https://drive.google.com/file/d/1Qnca6dITavOpRk4mYVik2BCb-G9nsaPi/view

1. Init project structure We will have 3 services in this project:

• HTTP server: works like a gateway to receive HTTP requests, validate and forward data to internal GRPC services.
• User GRPC server: CRUD for users, posts, follows, likes, and comments
• Newsfeed GRPC server: creates and returns newsfeed.

The project will be structured with the following folders:

• /cmd: The entry point for each service, containing main function. We will initializes all configs, service dependencies and the main services will be called to run here.
• /config: Configurations will be stored here.
• /pkg: Our backend implementation will be here. We can use /internal with the same purpose with /pkg. It's based on personal choice.
  • /pkg/handler: This folder will handle the request/response to each service. For HTTP server, it will have a HTTP server (gin). For GRPC servers, it will have a GRPC server attached with GRPC handler. The data model for these handlers will be XxxRequest and XxxResponse structs.
  • /pkg/service: This folder will store the business logic. The data model is business model. Handler and Repo layers will communicate with this Service layer by the business model here.
  • /pkg/repo: This is where we perform the actual operations to the external storage, such as database, cache, message queues ... The data model is defined based on each external storage library.
  • /pkg/util: Utility functions defined here.

2. Handler
3. Service
4. Repo
5. Setup local external dependencies

• MySQL:
  • Steps: pull image -> run mysql container with configs -> run SQL to create schemas
  • Pull: docker pull mysql
  • Run: docker run --name newsfeed-db -e MYSQL_ROOT_PASSWORD=123456 -p 33334:3306 -v {{absolute_path}}/data/mysql:/var/lib/mysql mysql
  • Exec mysql client in container: docker exec -it newsfeed-db mysql -p
• Redis: TBD
• Kafka: TBD
• Prometheus/Grafana: TBD

7. Generate GRPC servers and clients code:

• Quick start References: https://grpc.io/docs/languages/go/quickstart/, https://grpc.io/docs/languages/go/basics/, https://grpc.io/docs/languages/go/generated-code/
• Example code: https://github.com/grpc/grpc-go/tree/master/examples/helloworld
• Steps:
  • Download and install: protoc, protoc-gen-go, protoc-gen-go-grpc (follow Quick Start reference)
  • Write proto: /proto/user.proto
  • Generate grpc server: protoc --go_out=proto/gen --go_opt=paths=source_relative --go-grpc_out=proto/gen --go-grpc_opt=paths=source_relative proto/user.proto

8. Run demo:

• Setup MySQL in Section 5.
• Run User GRPC server: go run cmd/user_grpc/main.go
• Run HTTP server: go run cmd/http/main.go
• Test request:

curl --location 'localhost:33333/signup' \
  --header 'Content-Type: application/json' \
  --data-raw '{
  "user_name": "testuser",
  "password": "123456",
  "first_name": "Test",
  "last_name": "User",
  "dob": "01-01-2000",
  "email": "[email protected]"
  }'