drett

Resource tracking service for automated engines that allocate and---hopefully--- free up resources without human interaction. For example, auto-scaling, or active monitoring (probing) of IaaS cloud infrastructures with test instances.

The problem with these is that, sometimes, resources may not be freed (need kill -9, network problems, bugs, etc.) So the allocated resources are stuck, possibly with a ticking accounting clock.

drett offers a simple way to track these resources. The clients can

• register the intent of allocating a resource (so if the resource is allocated, but the client side only receives an error, human intervention can fix the problem)
• register the successful allocation of the resource
• register the successful release of the resource
• do the same with batches of allocations

drett is now in pre-pre-alpha condition, but it works. Only MongoDB is supported as a backend yet. The API may change drastically (the main goal is simplicity on client side). Later even garbage collection will be possible running on the backend database.

Files

Server side (server/):

• drett_server -- Application server. Uses Flask.
• drett_cgi_server.py -- CGI script as server. Apache must be configured accordingly. !!! Not maintained, probably won't work.
• drett/utils/command.py -- Abstract command class
• testconfig/ -- Configuration files for testing and as example
  • config.yaml -- main configuration file
  • logging.yaml -- logging configuration
  • mongo.yaml -- MongoDB specific configuration

MongoDB Connector (drett-mongo/):

• drett/plugins/mongo/connector.py -- The MongoDB connector implementation

Client side (client/):

• drett/client/drett.py -- A single module containing all services.
• drett-client-test -- Test client; configuration is wired in.

Trying

Using virtualenv is highly recommended.

You need two terminals, one for the server, one for the client.

Server side:

virtualenv dserver
source dserver/bin/activate
cd drett
pip install server
pip install drett-mongo
drett_server server/testconfig # Opens port 5001 on localhost

Client side:

virtualenv dclient
source dclient/bin/activate
cd drett
pip install client
drett-client-test # Connects to port 5001 on localhost

To see what's happening, or to tinker with the client, take a look at:

• server/testconfig/config.yaml and mongo.yaml
• client/drett-client-test

Misc

Environment: Python 2.7

License: LGPL 3.0 (client, plugins, libs) and GPL 3.0 (server)

Contact: Adam Visegradi "a.visegradi@gmail.com"