User Management Services

This is a Go Microservice Playground project, implementing User Management Services with REST, gRPC and GraphQL APIs, PostgreSQL storage, and Kafka notifications.

Provides:

• HTTP API
  • POST /api/v1/user
  • GET /api/v1/user/:id
  • GET /api/v1/users?page=1&limit=10&country=GB
  • PUT /api/v1/user/:id with JSON body
  • DELETE /api/v1/user/:id
• gRPC/GraphQL API:
  • Create
  • User
  • Users
  • Update
  • Delete
• User change notifications via Kafka
• Health check
  • GET /health

Tools and Dependencies

Tools

• Go 1.23.6
• GNU Make 4.3
• Docker 27.5.1
• jq 1.6
• graphviz 2.43.0

Dependencies

• PostgreSQL - for storing user data
• Apache Kafka - for notifying other services of user changes

Interactions

• User HTTP/gRPC services handle user management requests
• User data stored in PostgreSQL
• Notifier notifies other services of user changes via Kafka

Service Internals

Packages

• Services code
• Public and internal contracts
• HTTP server, router and handlers
• gRPC server, router and handlers
• Domain - user domain logic
• Storage - database adapter
• Notifier - user changes notifier

Used Go Modules

• Go-otelw for telemetry
• Viper and Viperx for configuration
• Gin for HTTP routing
• Pgx and Pq PostgreSQL drivers for storage and notifications
• Kafka client for publishing notifications

Interactions

REST

gRPC

Directory Structure

go-userv
├── cmd
│   └── user-*
│       ├── config.go
│       ├── config.yml
│       ├── Dockerfile
│       └── main.go
├── db
│   └── postgres
│       ├── migrations
│       └── init.sql
├── contract
│   ├── dto
│   │   └── *.go
│   ├── graphql
│   │   └── *.graphql
│   └── proto
│       └── *.proto, *.pb.go
├── internal
│   ├── contract
│   │   ├── domain
│   │   ├── server
│   │   └── storage
│   ├── domain
│   ├── notifier
│   ├── router
│   │   ├── grpc
│   │   └── http
│   ├── server
│   │   ├── grpc
│   │   └── http
│   └── storage
│       └── postgres
├── make
│   └── *.mk
├── test
│   └── integration
├── docker-compose.yml
├── go.mod
├── go.sum
├── Makefile
└── README.md

Build System

The service build system is constructed with GNU Make and Docker BuildKit.

• Makefile and make/*.mk
• docker-compose.yml
• Dockerfile

Make

• Display help

  make help

• All - install, lint, test, coverage, build, run

  make all

Step by step

• Install project

  make install

  • This installs required tools and Git hooks.

• Lint

  make lint

  • Currently limited to Go files only, mocks_*.go excluded.

• Test

  make test

  • Runs:
    • Router unit tests
    • REST, gRPC, GraphQL integration tests
  • Generates test results in JUnit XML Format, ready to be consumed by CI/CD pipelines, e.g. Jenkins, GitLab CI/CD, CircleCI, Azure DevOps, etc.

• Make coverage report

  make coverage

  • This generates a coverage report in HTML format, try to open it in a browser

• Generate dependency graph

  make deps

  • Generates dependency graph in docs/dep-..

• Build docker images

  make build

• Run all

  make run

  • Runs User Service and 3rd party dependency services in Docker containers

Logs

• All Logs

  docker compose logs -f

• Selective Logs

  docker compose logs -f user-rest

  docker compose logs -f user-notifier kafka

  docker compose logs -f user-grpc postgres

• Start dependency services only

  make doco-up-dependencies

  • Now you can run and debug the user-* service in vscode

• Kafka consumer In 2nd terminal

  ./test/scripts/kafka-consumer.sh

  • This allows to observe user changes

• Create, list, get, update, delete users In 3rd terminal:

  • REST - use UUID from the output of list-users.sh

    ./test/scripts/create-users.sh
    ./test/scripts/list-users.sh 
    ./test/scripts/get-user.sh UUID 
    ./test/scripts/update-user.sh UUID 
    ./test/scripts/delete-user.sh UUID

  • gRPC
  • GraphQL

• Stop

  make stop

  • Stops all running services

• Clean

  make clean

  • Stops running services, removes all containers, mocks and generated folders

• Remove docker volume

  docker volume rm go-userv_user-data

  • Removes the docker volume with user data in PostgreSQL database

• Health check

  ./scripts/health-check.sh

  • Returns health status of the User Service

TODO

• More unit tests
• API annotaions and documentation
• Telemetry