go-microservices-goldcopy

A Reference project to implement microservices using go programming language. This project acts as a template/goldcopy to setup and implement microservices using Golang within short period of time.

This application has the following features:

A library microservices that exposes APIs to store, retrieve, update and delete list of books in database
Provide docker and docker-compose tempates to quickly build docker images, run containers and push the containers to docker registry
Custom logging to print all request and response from handlers
Demonstrates the use of interceptors to inject headers into the response
Provides a health monitoring API to check the service and DB health status

Tools and Technologies

This reference project uses the following tools and technologies:

Technology	Version	Description
Golang	1.13	Programming language
go-chi	2.1.0	Router Framework
mysql	8.0	Database
gorm	1.9.12	ORM framework
zerolog	1.17.2	Logging framework
Docker	18.09.2	Container Creator
git	2.20.1	Soure Code Management
Goclipse	0.16.1	Integrated Developement Environment

Deliverables

The deliverables for the application can be found at the below location Library-Service/deliverables

Deliverable	Summary
Swagger.yaml	Swagger documentation for library-service API
ProjectStructure.PNG	Diagram depicting the project structure

Assumptions

Docker is installed in your system following the guide
Golang is installed in your system following the guide and the $GOROOT and $GOPATH are set correctly
The code is expected to use Goclipse project structure for GoProjects

Execution

Run in local

clone the project
Open terminal and navigate to the following src folder

[PROJECT_LOCATION]/go-microservices-goldcopy/library-service/src

Run following command to build the project
```
$ docker-compose build
```
Run following command to run the project
```
$ docker-compose run
```
go to your browser and check for http://localhost:9090 you should see "Hello World!!" printed on the browser

Run Docker image

An docker image of the code is currently pushed into public docker hub repository. Follow the below steps once docker is installed in your local machine

Open terminal and pull the docker image

$ docker pull ravikiran763/library-service

run the following command to start the library services

$ docker run -d -p 9090:9090 ravikiran763/library-service /bin/bash

go to your browser and check for http://localhost:9090 you should see "Hello World!!" printed on the browser

Example

Go to browser and hit the following URL : http://localhost:9090/api/v1/library/books

Expected output

[
   {
      "id":1,
      "title":"I Too Had a Love Story",
      "author":"Ravinder Singh",
      "published_date":"2008-01-01",
      "image_url":"https://images-na.ssl-images-amazon.com/images/I/81phwRtlzCL.jpg",
      "description":"I Too Had a Love Story is an English autobiographical novel written by Ravinder Singh"
   }
]

Technical Design

Project Structure

Package Structure

Package	Summary
library-service	code containing library microservices
library-service/src	golang code of microser
library-service/src/config	configuration files
library-service/src/main	entrypoint to the application
library-service/src/model	models for library service
library-service/src/repository	classes to interact with database
library-service/src/server	contains routers and handlers of the application
library-service/src/setup	setup files used during build
library-service/src/server	utility and constant files

Model

Class	Summary
book.go	Domain object representing a book
bookDto.go	Data transfer object for book domain object
bookForm.go	presentation object for book domain object

Class Design

Class	Summary
libraryApp.go	Entrypoint to the Application consisting main() method
appConfig.go	Contains configuration related to applction like server details etc
ormConfig.go	Contains configuration related to database and gorm
bookRepo.go	Repository class to perform CRUD operation on Book table
handler.go	Application request handler
handlerWrapper.go	Wrapper for request handler and logging
rootHander.go	handles request to '/'
libraryHander.go	handles request to '/api/vi/library-service'
libraryHander.go	handles request to '/health'
router.go	routes the request to necessary handler
responseInterceptor.go	intercepts router reponse
constants.go	contains application constants
logger.go	wrapper to zerolog framework
logEntry.go	log entry formatter

Future Enhancements

Implement swagger generator for the router and handlers
Implement service-discovery, load-balance and gateway
Deploy in kubernates and implement liveness and readiness probe to monitor health
Deploy in cloud
Create another microservice and demonstrate communication between services
implement OAuth security

Contact Information

Author : Ravikiran Butti, Email Id : (ravikiran763@gmail.com)

rbutti / go-microservices-goldcopy

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