A Python implementation of a rudimentary key/value server.

dblume dblume Update http to https in README.md 77a7eb3 @ 2023-03-16 08:13:18
.htaccess first commit 2016-09-08 23:30:02
LICENSE.txt Improve the documentation a little. 2016-09-09 10:52:19
README.md Update http to https in README.md 2023-03-16 08:13:18
auth_sample.txt first commit 2016-09-08 23:30:02
filelock.py first commit 2016-09-08 23:30:02
index.py Remove some extraneous ljust() calls. 2016-09-12 21:01:20
texttime.py Give Björn Lindqvist credit for texttime.py 2016-09-09 15:38:30
README.md

Key Value Store

kvs is an artisanal, hand-crafted online key/value store sourced by a California native. It is written in Python and yet harkens back to a simpler era before Redis and Riak.

Dependencies and Guarantees

kvs uses a local file for its backing store, and stores the data in the human-friendly YAML format. Its ACID properties are as follows:

  • Atomicity: Either all tuples in a transaction are successfully saved or none are.
  • Consistency: Only valid states are saved, and saves are atomic.
  • Isolation: All transactions are serialized.
  • Durability: System failure or restart won't break the store. Store writes are atomic.

Getting the project

You can get a copy of this project by clicking on the ZIP or TAR buttons near the top right of the GitList web page.

If you're me, and you want to contribute to the repo, then you can clone it like so:

git clone ssh://USERNAME@dlma.com/~/git/kvs.git

Building it

  1. Enable Python pages at your web server. See How to use Python in the web. My configuration is for Apache, hence the .htaccess file.
  2. Move auth_sample.txt to auth.txt, and replace yourauthorizationhere with a passcode you choose. chmod 600 the file or deny access to it via .htaccess.
  3. Optional: Use secure HTTP. I recommend getting a free SSL certificate from Let's Encrypt.
  4. If you don't have the YAML module, pip install pyyaml.

Using it

Here is a live instance that serves an index page. You can send a key to get a value like so:

https://kvs.dlma.com/?k=1GM35N000010

Special use case, here's how to get the value for the most-recently updated key of a list of keys. The list could contain any number of keys, but only one value will be returned.

https://kvs.dlma.com/?k=1GM35N000010,1GU44N010910

Here's the recipe for a cURL command to store a new value for a key:

curl --data "key=value&auth={authorization}" https://{url}

Here's the source code for a Roku channel client of such a service.

Is it any good?

Yes.

Licence

This software uses the MIT license.