Try moving the line
app = Doorcamdaemon()
to after the lines that create and set up logger. The traceback is telling you:
logger doesn't exist in line 18 where Doorcam's constructor tries to use it
Doorcamdaemon tries to construct a Doorcam at line 159 in its own constructor
So you can't create a Doorcamdaemon if logger isn't defined yet.
Some of the content you omitted in Doorcam.__init__
was related to this issue :)