EasyKVS

EasyKVS - an easy key value store server written in Python for small web apps

Starting the server

Install Python 2.7

Python 2.7 can be installed from https://www.python.org/downloads/

Install pip

Pip can be installed from https://pip.pypa.io/en/stable/installing/

Download the source

Run the git clone command to clone this repo to your machine

git clone https://github.com/alok-sm/EasyKVS.git

Install the Requirements

cd into the EasyKVS directory

cd EasyKVS

Install all the required packages using pip:

pip install --upgrade -r requirements.txt

Running server

Run the routes.py file:

python routes.py

Configuring the server (optional)

You can configure the server by modifying the config.json to suit you needs. Here's what each key does:

• host: This sets the host of the server. 0.0.0.0 allows you to access the server from a remote location whereas localhost only lets you access the API from a local site. You can also set this value to the IP address of the machine that you are using to run the server.

• port: By default, the server runs on port 8000 but you can change this if it conflicts with your webserver.

• storage_file: This key sets the file name of the file where the data is stored. If the file name does not exist, an empty file is created with the given name.

• debug: If this is set to true, the server auto restarts if the source code of the server changes

• threaded: If this is set to true, the server runs on multiple threads for better performance but debugging might be harder.

• strict_modify: refer to the PUT requestion section of this readme

• strict_delete: refer to the DELETE requestion section of this readme

• allow_empty_values: refer to the Using the API section of this readme.

Using the API

The API endpoint /kvs is all you need. You can send the following HTTP methods to perform actions on the API

The API throws an error if the key is null or empty

if the allow_empty_values key is set to false in config.json, the API will throw and error if the request body is null for the POST and PUT requests, i.e: The API will not let you set empty values. If it is set to true, the API will allow you to store empty values.

GET to list all keys

GET localhost:8000/kvs

Returns a list of all keys present on the db encoded as a JSON string with response code 200

GET to get the value of a key

GET localhost:8000/kvs/<key>

Returns the value of the key with response code 200 if the key exists Sends a 500 error if the key does not exist

POST to set the value of a key

POST localhost:8000/kvs/<key>

Send the request as url encoded (default with jquery), like this:

$.ajax({
    type: "POST",
    url: "http://localhost:8000/kvs/" + key,
    data: {value: <PUT YOUR VALUE STRING HERE>},
    success: function(){
        //THIS CODE IS CALLED WHEN THE REQUEST SUCCEDS
    }
})

Sets the value for the key to the text sent in the request body and will return a 204 empty response Sends a 500 error if you try to set the value for a key that exists

PUT to modify the value of a key

PUT localhost:8000/kvs/<key>

$.ajax({
    type: "PUT",
    url: "http://localhost:8000/kvs/" + key,
    data: {value: <PUT YOUR VALUE STRING HERE>},
    success: function(){
        //THIS CODE IS CALLED WHEN THE REQUEST SUCCEDS
    }
})

Modifies the value for the key to the text sent in the request body and will return a 204 empty response

If the strict_modify key is set to true in config.json, this will return a 500 error if you try to modify the value of a key that does not exist.

If the strict_modify key is set to false, this will behave similar to the POST request when the key does not exist, i.e: It will create a new key and set the value to the string in the request body.

DELETE to drop a key

DELETE localhost:8000/kvs/<key>

Deletes the key value pair for the key sent and will return a 204 empty reponse

If the strict_delete key is set to true in config.json, this will return a 500 error if you try to delete a key that does not exist.

If the strict_delete key is set to false, this will not throw an error and will simply send a 204 empty response even if the key to be deleted never existed

Troubleshooting

In some machines, you might need to use python2 instead of python and pip2 instead of pip

Checking stored values

You can run

python print_db.py <storage file name>

to print out the contents of the data stored in the specified file name in JSON format.

If no file name is specified, the script defaults to the file specified in config.json