Design Overview

Application Overview

2 main components/programs/processes, both executing Python code, which is Django-based:

  • Gunicorn # the HTTP front-end
  • Celeryd # the back-end for actually performing NETCONF updates and SNMP statistics queries

(compare ./runfod.sh, the default start wrapper script)

as well as

  • a common database,
  • either mysql or just an sqlite file
  • it contains the defined FlowSpec rules (active or inactive) + further model data
  • redis as a task broker (for tasks + messages)

in between Gunicorn and Celeryd

Python Code Overview

Installation directories

  • default installation directory proper: /srv/flowspy
  • default installation directory for Python dependencies (via virtualenv): /srv/venv

Overview of directories and files in the repository

Django Config

  • Django settings:
  • ./flowspy/settings.py

  • ./flowspy/settings_local.py (the latter included from the former for separating non-host specific settings from host-specific ones in cases of multiple installations)

  • ./flowspy/urls.py # Django urls config

Python program entry points

Gunicorn: ./flowspy/wsgi.py Celeryd: ./flowspy/celery.py Django manage: ./manage.py

task defintions shared between Gunicorn and Celeryd: ./flowspec/tasks.py

Overview of directories and files with code

proper Python code, partly shared by gunicorn and celeryd components:

  • ./flowspec/
  • for Gunicorn: views (for web UI), viewsets (for REST API), forms, validators;
  • common to both, Gunicorn and Celeryd: models, serializers, tasks;
  • snmpstats (for Celeryd),
  • further: admin.py (customization of Django /admin interface), helper classes
  • ./utils/
  • mainly helper classes,
  • but also proxy.py, which performs the actual NETCONF updates
  • ./accounts/
  • ./peers/

  • ./poller/: sub system for live-status message support in web UI

  • ./templates: Django web page templates