[Qgis-developer] WCS-T server

[John Donovan]

> Does the WCS-T service need functionality from the QGIS API (raster layer,
> raster provider, ...)? If not, it could also be an option to build the WCS
> service directly on top of the GDAL library.

I see the WCS server querying things like raster layers to filter out
vector layers, limit non-writable formats, and so on. The hardest
issue I've yet to solve to my satisfaction is adding coverages through
a WCS transaction - my initial thoughts are to have a configuration
somewhere that describes in what format and where an added coverage
should be.

I agree there is much less need for the QGIS layer between a WCS
server and GDAL, but it did strike me as a good idea to add WCS
support to the suite of GIS services QGIS provides.

> QGIS (wms) server could certainly serve as an inspiration on how to
> implement other geospatial web services on top of the QGIS API. Code-wise, I
> don't think the WCS server can use many parts of the wms server. It would
> probably go into its own executable (qgis_wcs.fcgi or similar), be linked to
> qgis_core and use functions from libfcgi for communication with the
> webserver.

I've yet to have a deep look at the QGIS Server code, but I expect
there will be considerable overlap in the boilerplate code such as
formulating a response to a GetCapabilities request for instance, so
some light refactoring should yield some good, consistent results. I'm
easily convinced either way with regards to having a separate
executable or not. The advantage of having one executable for all
requests is that it's simpler to set up and will "just work". But
separate executables would make for potentially better load-balancing,
as well as avoiding monolithic "do everything" applications.


-John Donovan

-- 
One of the advantages of being disorderly is that one is constantly
making exciting discoveries. - AA Milne