[source/native] refactor eid generation code
This set of related methods clutters the native source API.
It will be better served with a dedicated eid genrator object.
Related to #3526594.
[jcr: allocate the eid generator in __init__]
from logilab.common.shellutils import generate_password
from cubicweb.server.utils import crypt_password
for user in rql('CWUser U WHERE U cw_source S, S name "system", U upassword P, U login L').entities():
salt = user.upassword.getvalue()
if crypt_password('', salt) == salt:
passwd = generate_password()
print 'setting random password for user %s' % user.login
user.set_attributes(upassword=passwd)
commit()