krishnarajvr/microservice-mono-gin-gorm

Scalable Golang Microservices

Requirements

• Golang - 1.15 or higher recommended
• Mysql - 8.0 or higher
• Swag cli - For generating swagger docs
• Mockery - For generating mock classes for testing
• Docker and Docker-compose for the containerized setup - Not mandatory

Install Swag and Mockery

go get -u github.com/swaggo/swag/cmd/swag
go get -u github.com/vektra/mockery/cmd/mockery

Featues

• Multi tenancy support
• Scalable folder structure
• Config using .env
• Database migration
• GORM Integration
• Dependency Injection
• Swagger docs
• Separate handler, service, repository(repo), model
• Multi language support
• Json logger
• Makefile for commands
• Mock object integration
• Unit Test
• Integration Test
• Standard request and response and errors
• Common form validation
• Health endpoint
• Krakend Gateway integration
• Common error messages
• Docker
• Docker Compose
• Share library across service
• CRUD with pagination support
• Kubernetes

Overview

Gateway

Which act as a singe entrypoint for all the services

• Handle logs,trace,metrics collection
• Handle Authentication
• Handle ratelimit, Circuit breaker and many more

Common Library

• Common functionality shared accross the microserices , Refer micro-common

Account Service

• Manage tenants, users, authentication and authrorization

Product Service

• Manage product catalog. Demo purpose

Running Application

Go to the folders ./gateway ./account-service ./product-service and follow the readme.md files

Eg: Build Account microservice

 cd account-service

Setup packages locally

 go mod vendor

Change the config in .env for database and migrate the tables

make migrate-up

Generate API document to the ./doc folder using swag cli

 make doc

Swagger docs will be available at /swagger/index.html of the api path

Run service

make run 

or 

go run cmd/api/main.go

Generate mock files

make mock 

Test service

make test 

Swagger

• Access the url http://localhost:8082/swagger/index.html
• or through gateway once krakend is started http://localhost:8080/account/swagger/index.html

Same steps can be followed for product-service. For gateway steps are different. Please refere readme.md for gateway

Useful go commands

go clean --modcache   # Clean the mod cache
go mod vendor   # Initilize vendor folder locally
go mod download  #Download missing packages

Docker Compose setup

If Docker and Docker compose installed. Run below command from root directory

sudo docker-compose up

Create an account that can be used for /adminLogin api for token generation. Refer account service swagger.

curl -X POST "https://localhost:8080/account/v1/tenantRegister" -H  "accept: application/json" -H  "Content-Type: application/json" -d "{  \"domain\": \"eBook\",  \"email\": \"[email protected]\",  \"firstName\": \"John\",  \"lastName\": \"Doe\",  \"name\": \"Tenant1\",  \"password\": \"Pass@1\"}"

Can use the same user email and password for /adminLogin api

Folder Structure

├── app  # App Initialization
│   ├── app.go
│   └── database
│       ├── db
│       │   └── db.go
│       └── gorm
│           └── gorm.go
├── cmd # Starting point for any application
│   ├── api
│   │   └── main.go # Main application start
│   └── migrate
│       └── main.go # Migration start
├── config
│   └── config.go # App configurations
├── deploy
│   ├── bin
│   │   └── init.sh
│   ├── Dockerfile
│   └── prod.Dockerfile  
├── doc  # Swagger doc - Autogenerated
│   ├── docs.go
│   ├── swagdto
│   │   └── error.go  # Common errors used for swagger - Custom
│   ├── swagger.json
│   └── swagger.yaml
├── go.mod
├── go.sum
├── locale  # Language files
│   ├── el-GR
│   │   └── language.yml
│   ├── en-US
│   │   └── language.yml
│   └── zh-CN
│       └── language.yml
├── log
│   ├── micro.log -> micro.log.20210216.log
│   └── micro.log.20210216.log
├── Makefile
├── migration  # Migration files
│   └── 20210316142300_create_product.sql
├── module  # Application module - Main buisiness logic
│   ├── module.go
│   └── product
│       ├── handler.go
│       ├── handler_test.go
│       ├── inject.go
│       ├── mocks
│       │   ├── IProductRepo.go
│       │   └── IProductService.go
│       ├── model
│       │   └── product.go
│       ├── repo
│       │   └── product.go
│       ├── routes.go
│       ├── service
│       │   ├── product_service.go
│       │   └── product_service_test.go
│       └── swagger
│           └── product.go
├── README.md
└── util