How to configure Mountain Lion Server to run Web2py with wsgi?

Question

I am trying to config Mountain Lion Server to run Web2py with mod_wsgi. I get an error saying: "Premature end o scritp Header" wsgihandler.py (which is the wsgi file for Web2py).
I had it working fine in Snow Leopard and Lion Servers but not in Mountain Lion Server.
Thanks for your help.
Flavio.

Answer 1

I don't run web2py framework so can't tell you specifically.
That error means your script is not writing an http header to the browser so the browser can't decode whatever string it is getting. Your script is running as a plain old Python script. This is most likely because the Server.app in 10.8 now includes mod_wsgi built-in and configured from the GUI.
You can insert an intercept anywhere in your code to check any variable by saying this:
##########   PROGRAMMING HERE  ###############
print("Content-type:text/plain\n\n")
print(someVariable)
# raise SystemExit
The above sends an "http header" so the browser knows what to do. These headers are invisible in the browser window. But depending on your Python version, the pring statement may not work (I am running Python3). The SystemExit statement is optional, just in case your script crashes downstream.
WSGI sends a header like this:
startResponse("200 OK", [("Content-Type", "text/plain")])
but it sounds like mod_wsgi is not even being invoked. Normally your WSGI script is named *.wsgi and your Apache is set up to run the Python script as CGI under the mod_wsgi handler using this directive:
AddHandler wsgi-script .wsgi
The file having the config is located at
/Library/Server/Web/Config/apache2/httpd_wsgi.webapp.conf
where webapp is the name of your webapp. I would suggest copying the file called httpd_wsgi.conf and renaming it to your webapp name. When Server.app is configured properly, you enable wsgi webapps in the GUI Advanced wndow for your domain.