Barker is a hive mind for your clusters. But what the hell does that mean? Well, barker is intended to be a suite of pluggable tools which integrate together nicely to help you manage groups of servers.

The first component of barker is the PoD system. A "pod" is simply a piece of data; specifically metadata about a host or set of hosts. Pods are scripts written in the language of your choice that output JSON. Barker loads these pods on the fly to output (JSON-formatted) information about a given host.

Barker is capable of publishing the collected output of Pods as messages on an AMQP queue. See barker help publish for more information.

For now that is all, but there is definitely more to come! Barker is under active development and will change very frequently. You probably don't want to use it yet!

For now, clone the repo, set up a virtualenv, and python setup.py develop. There will be a real installation some day.

Barker loads barker/config.py in the repo directory, then loads /etc/barker/config.py if it exists. These are python files and must be written following python syntax. Configuration parameters are:

LOG_FILE

Path to the file which barker will log to.

LOG_LEVEL

Tune the verbosity of logging. Can be one of DEBUG, INFO, WARNING, ERROR, CRITICAL

POD_DIR

The directory containing PoD scripts for barker to load.

POD_TIMEOUT

Amount of time an individual PoD script can run before barker skips that PoD.

CONSOLE_LOG

Boolean controlling whether barker outputs logs to the console as well as its log file. Can be one of True or False

EXCHANGE

Name of the exchange that barker-publish-pod will publish to.

QUEUE_NAME

Name of the queue that barker-demo-listener will pull messages from.

QUEUE_USER

AMQP username to use when connecting to the queue service.

QUEUE_PASSWORD

Password used to authenticate to the queue service.

QUEUE_VHOST

AMQP virtual host to use when connecting to the queue service.

barker help [command]

Prints out a help message and exits. If a command is specified, prints specific usage help for that barker command.

barker pod [options ...] [-p pod ...]

Loads the specified PoD scripts (loads all by default) and outputs a JSON hash containing their individual data.

barker publish [options ...] queue_hostname [-p pod ...]

Connects to the specified queue host and publishes the specified pod(s) (or all of them if none are specified) to a fanout exchange. If no listeners are attached to the associated queues; the messages will be dropped.

examples/demo-listener.py

Connects to the specified queue host and waits for a single pod message, prints it out, acknowledges it, and exits. This is just a demo for how you might listen for pod information on the queue.