software

Since no such beast seemed to exist yet, I have hacked up a wrapper to turn an existing python CGI script into a WSGI application. The result is available from the sysfs download area as cgi2wsgi.py.

The wrapper requires you to rename the original CGI script to somecgi.py (pick a name), make it available in the python path, and set the name you gave the script in the wrapper wrapcgi method. This is due to the way it works: it mangles the environment and standard output, and then tries to import the CGI as a python module. Any output is gathered, split into headers and data and then returned to the WSGI server. An alternative approach could have been to create a full-fledged CGI environment and run the script by forking or another equivalent method, with the added bonus that this should work even to turn non-python CGI scripts into WSGI applications; but this looks like a lot more work than the import approach I used (which was tricky enough in certain details already).

The wrapper is not complete as it stands: there are a bunch of variables which are usually available to CGI scripts but aren't when the CGI is loaded by the wrapper. Also if your script uses globals and does not reset them to a sane state before use data may linger in between subsequent invocations. However, I have successfully run a few applications through it so it should provide a reasonably good base to start from. And it did show a few bugs which were not triggered in a standard CGI environment.
The best way to figure out weak spots in your CGI script is probably by running the wrapper in a WSGI server which is not run itself through CGI, to avoid the WSGI server environment leaking through to the application. If run standalone, the wrapper tries to use the OwlFish.com WSGIUtils to this purpose.

Bugfixes, enhancements and feedback welcome at mechanix on rack66.net.