Lymph

lymph is an opinionated framework for Python services. Its features are

• Discovery: pluggable service discovery (e.g. backed by ZooKeeper)
• RPC: request-reply messaging (via ZeroMQ + MessagePack)
• Events: pluggable and reliable pub-sub messaging (e.g. backed by RabbitMQ)
• Process Management

There's documentation on readthedocs.org.

Installation (as a dependency)

# py-monotime requires python headers, and gevent and cython require build-essential
$ sudo apt-get install build-essential python-dev

$ pip install http://py-monotime.googlecode.com/archive/5fb3eb35a8e25140204e957bd010991bfe8758e3.zip#egg=monotime
$ pip install https://github.com/johbo/gevent/archive/1.1-dev-20140506.tar.gz#egg=gevent-1.1-dev-20140506
$ pip install https://github.com/deliveryhero/lymph.git#egg=lymph

Development (of lymph itself)

$ git clone https://github.com/deliveryhero/lymph.git
$ cd lymph
$ pip install cython
$ pip install -r requirements/base.txt -r requirements/dev.txt
$ pip install -e .

Run tests with tox, build documentation with fab docs.

Running services

To run the example services, you can use the example node config in conf/local-zookeeper-rabbitmq-node.yml. You'll also need a local installation of ZooKeeper (with the configuration provided in the Getting Started Guide) and RabbitMQ:

$ export PYTHONPATH=examples
$ cp conf/local-zookeeper-rabbitmq-node.yml .lymph.yml
$ lymph node

You can then discover running services:

$ lymph discover

and send requests to them from the commandline:

$ lymph request lymph://echo echo.upper '{"text": "transform me"}'

To see the log output of a running service, try:

$ lymph tail lymph://echo -l DEBUG