KV Store

Overview

Basic KV store web application & CLI Interface written in Python. It has 2 components:

1. The WEB Server - This runs via Python flask web server and has 2 functionalites:
   a. /get - This requires an input of the "key" value for which the value has to be retrieved from the KV store.
   b. /add - This requires an input of the "key" and "value" that has to be added to the KV store.
   c. /get_all - This displays all the available KV pairs in the store.
2. CLI Interface - This is a CLI shell that consumes the WEB API and performs actions over the KV store.
   a. get <key> - Output the values of the provided key from the KV store.
   b. put <key> <value> - Add the KV pair to the KV store.
   c. watch - Subscribe to the changes happening to the KV store in real time.
   d. getall - This displays all the available KV pairs in the store.

This project contains 2 python files and 1 pickle data file to handle data persistance.

1. kvstore.py - This implements the Web API functionality of the project.
2. kv-cli.py - This implements the CLI client created to consume the KV Store Web Server.
3. store.pickle - This stores the KV pairs that are added to the KV Store. It is loaded once at the start of the API.

Requirements

Python 3.8.x and above.
Libraries used - flask, cmd, requests, pickle, sockets, gevent.

Installation and Usage

Download the requirements file and install the required libraries using pip.
$ python3.8 -m pip install -r requirement.txt

Start the Web Server (Default Port - 5000)
$ python3.8 kvstore.py
To run the Web Server in background in Linux - $ nohup python3.8 kvstore.py &

Use the CLI Shell
$ python3.8 kv-cli.py

Examples

1. $ python3.8 kv-cli.py
   CLI Client to consume the KV Web API. Type help or ? to list commands. To exit press 'Ctrl + D' or fire 'quit' command.

   kvstore> put test 1  
   b'Successfully added Value - 1 for Key - test'  
   kvstore> get test  
   b'1'
   kvstore>  
   

2. Invoke 2 simultaneous CLI shells - one for watch and another to make changes to KV.
   $ python3.8 kv-cli.py
   CLI Client to consume the KV Web API. Type help or ? to list commands. To exit press 'Ctrl + D' or fire 'quit' command.

   kvstore> watch  
   b'Successfully added Value - 1 for Key - test'  
   b'Successfully added Value - 2 for Key - test1'  
   ^C  
   Got keyboard interrupt, exiting!!  
   kvstore>  
   

   $ python3.8 kv-cli.py
   CLI Client to consume the KV Web API. Type help or ? to list commands. To exit press 'Ctrl + D' or fire 'quit' command.

   kvstore> put test 1    
   b'Successfully added Value - 1 for Key - test'  
   kvstore> put test1 2  
   b'Successfully added Value - 2 for Key - test1'  
   kvstore>  
   

3. Help to see all the commands.
   $ python3.8 kv-cli.py
   CLI Client to consume the KV Web API. Type help or ? to list commands. To exit press 'Ctrl + D' or fire 'quit' command.

    kvstore> help  
   
    Documented commands (type help <topic>):
    ========================================
    EOF  get  help  quit  put  watch getall  
    kvstore> help  
    Get the value of the provided key.  
    Syntax - get <key>  
    kvstore>