Created: 2011-07-11 21:27
Updated: 2019-02-09 08:45
License: gpl-3.0

OpenNode Management Service

OpenNode Management Service (OMS) is a modular framework for creating management applications. Its initial target was hosting the OMS Knot cloud management platform.

OMS main documentation is generated and can be viewed online.


Currently the only requirements are Python 2.7, its headers, GCC and GNU Make.

Mac OS X

  1. Install Python 2.7 in one of the ways:
    • using MacPorts

        sudo port install python27
    • using Homebrew

        brew install python
    • manually


On Ubuntu Python 2.7 is shipped out of the box, so no installation is needed.

To work-around version incompatibility between system-wide setuptools and the one needed for buildout, virtualenv is needed. This work-around, though, results in a warning BROKEN_DASH_S_WARNING each time a script in bin/ is run. It can be safely ignored.

  1. Install build tools:

     sudo apt-get install --yes g++ make
  2. Install Python headers:

     sudo apt-get install --yes python-dev
  3. Install Virtualenv:

     sudo apt-get install --yes python-virtualenv


  1. Get the code:

     git clone
     cd opennode-management
  2. Boostrap buildout:

    • Without Virtualenv:

        python -v 1.7.0
    • With Virtualenv:

        virtualenv --setuptools venv
        venv/bin/pip install setuptools==1.3
        venv/bin/python -v 1.7.0
  3. Run buildout:

  4. Restrict access to Python egg cache to avoid future warnings:

     chmod go-rwx -R $HOME/.python-eggs

Note: Steps 2 and 3 may fail with timeout error. It happens due to heavy load on PyPi package repository. It is safe to repeat the failed command once again.

Note: Steps 1, 2 and 4 must be done only once. The 3rd one must be done each time buildout.cfg gets changed.


  1. Setup user accounts with the bin/omspasswd utility:

     bin/omspasswd -g admins -a john
     bin/omspasswd -g users -a jane
  2. Start OpenNode Management Service:

  3. It should be possible to log into OMS shell using credentials specified in 1st step:

     ssh -l john localhost -p 6022


  1. ./


You can quickly enable plugins by adding the plugin buildout snippet to the eggnest dir, e.g:

bin/plugin install opennode.oms.onc

This will download the published egg for the plugin. If you want to use a development plugin you have to specify the plugin checkout:

bin/plugin install opennode.oms.knot -d ../opennode-knot


During development, you can use the autoreload mode with bin/omsd -d. If you make changes in the dependencies, just rerun bin/buildout. You can use bin/buildout -o to avoid waiting for the network, if you already have the eggs in the cache.

You can get a python prompt with the correct python path with bin/python.

High level architecture

The core consists of:

  • The models:

    These are mostly ORM backed and some transient classes which contain CRUD and most of the domain logic.

  • Traversal:

    Mapping of URIs/paths to model objects, i.e. /datacentres/123/computes/9 -> .

  • Interaction layers a.k.a endpoints (in Twisted terminology):

    This is a thin layer that takes an incoming request/interaction (either SSH/vconsole, HTTP or WebSocket) which is always bound to a URI/path (cwd in SSH, request URI in HTTP/Websocket) and maps it, using traversal, to a domain object and executes appropriate methods and returns a result.

    This layer can be thought of as the controller.

    The interaction layer is as thin as possible as traversal, domain logic and security are in the core, and serialisation is generic.

Interaction layers/endpoints

The primary interaction layer is the HTTP REST endpoint which contains an HTTP request handler and a set of views, one for each content type. The views can either be generic over content types, or specialised for specific models. Generic is preferred over specialised though.

The WebSocket endpoint is in big part complementary to the HTTP REST endpoint. It is mostly an alternative carrier or transport mechanism for individual HTTP-like requests. In addition, it is used to push a stream of data/events to the browser for real time updates of the UI. As HTTP REST like requests can be transported from client to server over this layer, it also provides a performance boost over classic HTTP as it eliminates any request overhead both in terms of responsiveness and network/resource usage. It is also easier to manage than classic HTTP as browser security restrictions do not apply to WebSocket connections.

The SSH virtual console endpoint provides a bash-like pseudo shell over SSH that exposes a filesystem-like hierarchy to navigate in and manage the server infrastructure environment. It provides or will provide all the basic shell-like commands such as cd, ls, pwd, cat, mv, cp and rm. It also provides the generic command set to modify attributes of objects.


OpenNode Management Service is released under an open-source Apache v2 license. Commercial support is possible, please contact for more information.

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