1. COWS CEDA OGC Web Services Framework Stephen Pascoe

2. COWS Motivation Develop lightweight OGC services Don't attempt to implement the specifications in full Enable integration with custom web applications Build upon a fully-featured web framework Layered design Support multiple OGC services in one stack

3. COWS Architecture Built on Pylons web- appliction framework Python Eggs – Automatic download/install of components WSGI – A protocol for deploying Python web- apps to production HTTP servers HTTP Server Paste Pylons Middleware Web Application COWS WMSWCSW*S Data Model WSGI Apache + mod_wsgi, FastCGI, Python HTTPD E.g. Authentication Library Standard Interface Application-specific Code

4. COWS Package Structure cows: top level package cows.model Implements toe OWS-common data model cows.service Provides service interfaces and implementations cows.pylons OGC service controllers and XML templates OGC parameter and exception handling due for reorganisation cows.pylons.project_templates pre-canned application template(s)‏

5. WSGI Middleware Add security to a COWS Application by adding security middleware Python Paste package enables inclusion of middleware via a config file – no change to COWS code required: CowsApplication AnotherFilter AuthenticationFilter [pipeline:CowsApplication] pipeline = AuthenticationFilter AnotherFilter CowsApplication Example middleware chain: HTTP Request HTTP Response

6. Development workflow Install COWS Create web-application from template Customise Test Package Deploy

7. Example Applications

8. IPCC Data Distribution Centre

9. NDG Discovery Portal http://www.ipcc-data.org/maps

10. NERC Portals Project 2 Different Station datasets Integrate with CSML Pylons Application plots CSML Features 2 visualisation interfaces KML references plot service COWS WMS provides in- browser support.

11. DEFRA UKCP Portal Highly Dimensional Dataset Time Period Emission Scenario Percentile (CDF)‏ Meaning Period UKMO UM Rotated Grid but we need to plot it on GoogleMaps (Transverse Mercator)‏ Custom WMS operation to serve Grid-box values as JSON

12. COWS Future Clean-up and publicised release for NDG3 cows-0.3 on the way WFS being developed as part of the C-SEKT project WPS developed for UKCP portal. Will be included in COWS in the future (post v0.3)‏