plume/twistd runs code as root before dropping privileges

[cvandeplas]

Plume is, by default, dropping privileges to the user nobody.
This only happens after the whole code was run once as root, privileges are only dropped afterwards when running transforms.
This can cause problems with permissions with for example logging, file creation, ...

You can easily reproduce this by creating a file or folder within the code (outside of a function):

os.mkdir('/tmp/testing_plume')

Start twistd:

twistd --pidfile=/var/run/plume.pid --rundir=/var/plume --uid=65534 --gid=1001 --no_save --nodaemon web --wsgi=canari.tas.plume.application  --port=tcp:8080

Notice the folder is owned by root and not nobody:

root@ubuntu:/var/plume# ls -al /tmp/
drwxrwxrwt 10 root root 4096 Dec 25 20:59 .
drwxr-xr-x 24 root root 4096 Dec 25 14:25 ..
drwxr-xr-x  2 root root 4096 Dec 25 17:43 testing_plume

I however have no idea yet on how to prevent this from happening.
To work around this, either move all the code to functions, or change permissions os.chmod('/tmp/testing_plume', mode=0o777) which is not the best.