⚓️ Ports - example of Microservices architecture, gRPC/protobuf, HTTP

The project contains an example of microservices written in Go. The purpose of the system is to store, update and return marine port objects. There are 2 microservices (Client and Ports) that communicate using gRPC. Client service exposes the HTTP interface to add and list ports.

Features

• 🤝 gRPC Client and Service communation
• 💿 Storage using repository pattern
• 🟢 Tests
• ✅ Lint using golangci
• 🚢 Docker and docker-compose
• 🔥 Read JSON lazy, allowing to consume JSON of huge size, larger than memory
• 🔧 Go modules
• 🎉 Github Actions to run tests and lint on push

Prerequisites

brew install protoc-gen-go

Ports service

Ports service is used to store ports. Port can be inserted or updated in DB. Ports service is a gRPC server. The repository is an interface that includes several functions to upsert (insert or update), list all ports. There is an in-memory implementation of the repository that stores all data in a map.

Ports service expects following environment variables set:

• PORTS_GRPC_PORT port number gRPC server will be listen to

Client service

Client service on startup reads ports from JSON file and calls upsert on ports service to store ports. Client service provides HTTP API to get a list of all ports.

Client service needs following environment variables:

• HTTP_PORT HTTP port REST service will use
• PORTS_ADDRESS Address of Ports gRPC server
• PORTS_JSON Path to ports.json file

Folders structure

There are 2 folders:

• ports_service contains the implementation of Ports Service, repository and gRPC server.
• client_service contains the implementation of Client Service.

Generate structures and gRPC client and server from protobuf

Script gen.sh generates protobuf structures, functions, and gRPC client and server code. ports.proto file contains a description of the Ports service.

Tests

To run tests run the script test.sh. The script will run tests in all 3 folders.

Running in docker

Client and Ports services contain dockerfiles to build and run them in containers. Client service starts after Ports service. docker-compose.yml file describes services in docker.

Run docker-compose up --build to start both services.

Docker output:

Starting ports_ports_service_1 ... done
Starting ports_client_service_1 ... done
Attaching to ports_ports_service_1, ports_client_service_1
ports_service_1   | time="2021-02-04T20:17:35Z" level=info msg="Starting Ports GRPC Server on port 4040" Server="Ports GRPC Server"
client_service_1  | time="2021-02-04T20:17:37Z" level=info msg="Total ports loaded: 1632, failed: 0" Server=Client
client_service_1  | time="2021-02-04T20:17:37Z" level=info msg="🆙 Starting server at port 8080" Server=Client

Open second terminal and run curl :8080/ports to get a list of all ports in JSON format

Press Ctrl+C to stop services gracefully.