URL Go

URL Go is a simple python3 flask application designed to provide an open source url shortener service.

You can check for a live demo of URL Go on go.northy.xyz

How to install

To install URL Go , you need to:

git clone https://github.com/northy/url-go.git
cd url-go

Installing dependencies

URL Go uses pipenv to manage dependencies, so install pipenv with:

sudo pip install -r requirements.txt

or:

sudo pip install pipenv pipenv-shebang

Configuration

To configure URL Go, you need to edit url_go/settings.py, with the options being as follows:

• SERVER_NAME (string) - The URL for the server to listen requests on. This can be your domain if you are hosting on one.
• SQLALCHEMY_DATABASE_URI (string) - RFC-1738 compilant URL that indicates SQLAlchemy how to connect to the database. For more information on how to create the url, check this link
• HCAPTCHA_ENABLED (boolean) - True or False value to enable hCaptcha service when creating new shortened URLs.
  • HCAPTCHA_SITE_KEY (string) - Site key for hcaptcha.
  • HCAPTCHA_SECRET_KEY (string) - Secret key for hcaptcha.
• LIMIT_SHORTENS (boolean) - True or False value that indicates if you want to limit how much shortens an user is able to make until a refresh request is made.
  • LIMIT_COUNT (integer) - The numeric value of how much shortens the user can make.
• MINIMUM_URL_LENGTH (integer) - Numeric value that represents the minimum length of the shortened URL.
• URL_OFFSET (integer) - Numeric offset for the first URL value.
• URL_ALPHABET (string) - String of characters that will be used to create the shortened URLs.

Example configuration file:

import string

SERVER_NAME = "127.0.0.1:5001"
SQLALCHEMY_DATABASE_URI = "sqlite:///db.sqlite3"

HCAPTCHA_ENABLED = False
HCAPTCHA_SITE_KEY = ''
HCAPTCHA_SECRET_KEY = ''

LIMIT_SHORTENS = False
LIMIT_COUNT = 0

MINIMUM_URL_LENGTH = 4
URL_OFFSET = 0
URL_ALPHABET = string.ascii_letters + string.digits

Configuring database:

After changing the configuration file, run create_db.py to generate the tables on the database.

pipenv run python create_db.py

Running URL Go

If you are running URL Go on a test environment, you can use the following command to run the server:

pipenv run flask run

However, that's not recommended by flask, so you should use a production WSGI server instead. A WSGI configuration file is present as webapp.wsgi, where you should change "/PATH/TO/APP/" to the path of the URL Go folder.

WSGI on apache

If you are running apache, you can install mod_wsgi to run the application.

An example Virtual Host configuration for apache would be:

<VirtualHost *:80>
    ServerAdmin admin@SERVER_NAME
    ServerName SERVER_NAME
    WSGIScriptAlias / /PATH/TO/APP/webapp.wsgi
    <Directory /PATH/TO/APP/>
        Options FollowSymLinks
        AllowOverride None
        Require all granted
    </Directory>
</VirtualHost>

Refreshing the url limit

To refresh the url limits, just make a web request to SERVER_NAME/refresh.

curl SERVER_NAME/refresh

You can also add a cron job to do this periodically. An example cron job for running each hour would be:

0 * * * * /usr/bin/curl --silent --show-error -m 120 SERVER_NAME/refresh &>/dev/null

Note that the refresh job will only be completed if the issuer address is 127.0.0.1

Libraries used:

• Flask - Main web framework
• pipenv - Install and manage environments
• pipenv-shebang - Shebang for pipenv
• SQLAlchemy - Manage SQL Database
• python-dotenv - Load environment files
• requests - Manage requests
• passlib - Hash and verify passwords