Dcard Demo

Simple Live Demo

Front-end

I've deployed a simple shorten-URL Demo that have developed by React. If You wanna demo,visit the link below(a bit slow~):

https://shortener-url.herokuapp.com/

Backend

API Server have been deployed on AWS EC2 and the host name:

https://ec2-18-141-10-193.ap-southeast-1.compute.amazonaws.com

Using this API to check server active state. If it's being active,you'll receive a pong message

https://ec2-18-141-10-193.ap-southeast-1.compute.amazonaws.com/ping

Tool in use

Gin-Gonic(backend framework)
Mysql database
GROM
Validator v10
Viper
Swagger-API

APIs Document

Allowing to access Swagger-API if server is in debug mode

Mode: debug

{HOST}/swagger/index.html

APIs

Uri	Method	Desc
/api/v1/urls	POST	Upload Longrest URL with expired date in UTC format
/{url_id}	GET	Redirect to original url with url_id

How it work

Upload url

Getting uploaded data from the HTTP Form and validating the data via Validator including URL and time
Create a new tuple/record to the DB with Form data if data is validated successfully

After tuple is created, server'll use base62 Algorithm to generate the short_URL depending on Unix time

base62 Algorithm Implementation
Input int64(unix time) and output a string which string consists of a-z, A-Z,and 0-9(total 62 characters)

//Base62URL in order to generate shorten url string,it's consider to use base 62 approach(6byte)
func Base62URL(id int64) string {
  if id < 0 {
    return ""
  }
  //[a-z,A-Z,0-9]
  urlStr := "0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ" //total 62 character
  url := ""

  for {
    if id <= 0 {
      break
    }
    str := urlStr[int(id%62)]
    url += string(str)
    id = id / 62
  }
  return url
}

After the short_URL is generated by the algorithm, the short_URL will be updated in DB

Redirect to original URL

Getting short URL id from URL path, for example: the short URL_id is abc123
We'll query the database and check the URL_id (Checking steps below)
- Step 1 :whether the URL_id exist
  - 1.the URL_id not exist,return 404 Not Found Immediately
  - 2.the URL_id exist in the database,it goes to the next step
- Step 2 :whether the url_id expire
  - 1.the URL_id expired, return 404 Not Found Immediately
  - 2.the URL_id does not expire, redirect to the original_URL

RyanTokManMokMTM/dcard_demo_shortenurl