Fossgis: mapproxy workshop - Dominik Helle and Oliver Tonnhofer¶

Tags: fossgis, python

After the actuall conference was over, I attended another workshop: about mapproxy. At my work, we have done nothing regarding map caching and proxying and tiling (we have done a lot on regular web caching, though). We’re “just” generating complete images on demand via WMS as lots of our data is pretty dynamic. But there is mostly-static data. And by setting up our software differently, tiling and proxying and caching becomes possible. At the moment I can only dream about what that’ll do to the speed of our web applications... :-) So that’s why I attended this workshop: getting to know at least one of the available map proxy tools.

Ok, what’s mapproxy?

• Started in 2008.
• Made with python, so platform-independent. (It is harder to install on windows than on osx/linux, though, probably because of some dependencies).
• It is more or less a proxy, a cache, between a WMS server and clients. It speeds it up.
• The advantage of mapproxy compared to most other proxies is that it supports all of WMS, so desktop clients also work fine with it.

A core piece of functionality of mapproxy is that it tiles the map. In order to cache a map, it subdivides it into parts.

What are the possible input data types?

• WMS
• WMS-C
• TMS
• Tiles (like google maps, openstreetmap).

And what can come out? (Note that this means that you can theoretically take google tiles and turn them into a WMS service!)

• WMS
• WMS-C
• TMS (Tile Map Service, so google-tile-like, only sepecified properly)
• KML

Some comments from the hands-on-keyboard part of the workshop:

• MapProxy is just an pip install MapProxy away. Well packaged!
• You can create an example configuration with paster. This made a good impression on me, as it means it is really a well-packaged python product.
• Whoever designed those German keyboard layouts should be shot. Twice. Darn, I kept mis-typing all the time.
• Hey, a nice .ini python paste file to run the server with. Integration with standard python wsgi tools and so easy integration into web servers. Looks good.
• Some instructions are at http://workshop.omniscale.net/workshop.html

In the end, I found it a very good workshop. Glad I attended. And the mapproxy software left a very good impression on me: I’m looking forward to using it.