Debugging with lite-server.py in FreeIPA

Kerberos doesn’t tell you who you are. Seems like a funny thing, but when you use Kerberos Auth on the web, the browser has not way of telling you “this is the principal that you are using.” For the UI in FreeIPA, I need to display just thins information. To find it, I have to look to the server to tell me.

Thus begins my study of FreeIPA plugins. I wrote a simple plugin, the whoami plugin, that did just what I needed. I returned the Principal in the summary, and all was good.

Now I need more. I need to know the role groups of which the current user is a member. This information is on the user object already. So, good-bye whoami plugin: we are going to add your behavior to the user plugin, where it belongs.

The key piece of information that made this work possible was how to get a breakpoint to stop the code and let me step through it. The trick, probably old hat to the Pythonistas out there, but new to me was this simple line:

import pdb; pdb.set_trace()

Without that, none of the breakpoints I’d set would get executed, maybe due to threading or something. Not sure, but with this, I was able to determine that what I needed to do was to modify the filter.

I ran the lite-server like this:

./lite-server.py

Which is actually preferable to running it like this

python -m pdb lite-server.py

As you don’t have to type cont, and the debugger is still activated by the breakpoints.