C

configdb

A REST relational abstraction on top of arbitrary database backends.

Overview

configdb is a relational database for administrative databases (i.e., stuff that gets read more often than written to) with a focus on stability and usability rather than performance.

When provided with a simple JSON schema of your data, it will offer:

  • An HTTP API to a database implementing your schema;
  • ACL and validation support for every field, and a pluggable authentication system (which can use objects in the database itself);
  • a Python client library to manipulate such database;
  • a client tool to manipulate the database from the command line.

This framework is meant for those small databases where the ability to make quick manual changes is critical: for instance, databases used to store configuration and management information. As an example, in our organization we're currently using one instance of configdb to store data about hosts, users and groups, and another one for source code projects.

When managing systems, there is often the necessity of this kind of lightweight authoritative database. configdb is meant to remove the tedium of writing your own solution: just craft an appropriate schema, and the management functionality is already taken care of.

Caveats and Limitations

Plenty, of course:

  • The relational capabilities of the schema are (purposedly) limited, as it will only model many-to-many relations.
  • The performance characteristics are sub-optimal: serialization and validation have their cost. Furthermore, the network transport is HTTP, which adds overhead, etc. Queries, for some backends, can be particularly expensive since we might have to do filtering on the client side (in the configdb server).
  • Transaction support is currently limited to what is provided by the underlying SQL storage backend (so, possibly, none).