Doubledecker

DoubleDecker messaging system

View project on GitHub

DoubleDecker logo

DoubleDecker messaging system

DoubleDecker is an hierarchical distributed message system based on ZeroMQ which can be used to provide messaging between processes running on a single machine and between processes running on multiple machines. It is hierarchical in the sense that message brokers are connected to each-other in a tree topology and route messages upwards in case they don't have the destination client beneath themselves.

DoubleDecker currently supports two types of messaging, Notifications, i.e. point-to-point messages from one client to another, and Pub/Sub on a topic. The Pub/Sub mechanism furthermore allows scoping when subscribing to a topic. This means that a client can restrict the subscription to messages published only within a certain scope, such as to clients connected to the same broker, a specific broker, or different groups of brokers.

DoubleDecker currently supports multiple tenants by authenticating clients using public/private keys, encrypting messages, and enforcing that messages cannot cross from one tenant to another. Additionally there is a special tenant called 'public' that can cross tenant boundaries. This can be used in order to connect clients that are intended to provide a public service, such as a registration service for all tenants, a name-lookup service, or similar.

Double Decker tenants messaging

This initial release contains only the Python version of the DoubleDecker broker and client library (and a demo client). A version in C is planned to be released shortly.

This work is carried out within the UNIFY FP7 EU project. For more information about the purpose and how we use DoubleDecker, see:

INSTALLATION

DoubleDecker requires Python > 3.3. To install on Ubuntu 15.10, run the install.sh script which performs these actions:

#install dependencies 
apt-get update
apt-get install python3-setuptools python3-nacl python3-zmq python3-urwid python3-tornado git
# clone the code
git clone https://github.com/Acreo/DoubleDecker.git
# install the doubledecker module and scripts
cd DoubleDecker/python
sudo python3 setup.py install
# generate public/private keys
cd /etc
mkdir doubledecker
cd doubledecker
# create keys for 4 tenants, public, tenant a, b, and c
ddkeys.py (input "a,b,c")

USAGE

# start a broker listening for TCP connections on *:5555, using the keys
# from broker-keys.json, called 'broker0'
ddbroker.py -r tcp://*:5555 -k /etc/doubledecker/broker-keys.json broker0
# start a client from tentant A, called cli1, connect to broker0
ddclient.py -d tcp://127.0.0.1:5555 -k /etc/doubledecker/a-keys.json cli1 a
# start a second client tentant A, called cli2, connect to broker0
ddclient.py -d tcp://127.0.0.1:5555 -k /etc/doubledecker/a-keys.json cli2 a
# now you can use the CLI interface to send notifications
# from cli1 to cli2 or to subscribe and publish messages
# to send a notification from cli1 to cli2
Send Notification -> Destination: cli2 -> Message: hello -> Notify
should result in message "hello" appearing at cli2
# to subscribe to topic "alarms"
Subscribe to topic -> Topic: alarms -> Scope: region -> Subscribe
# to publish on topic alarms
Publish message -> Topic: alarms -> Message: warning -> Publish

LICENSE

DoubleDecker is licensed under LGPLv2, for more details see COPYING.LESSER.

The file 'python/doubledecker/trie.py' is from the Google PyTrie module, licensed under version 2.0 of the Apache License.