Description Arvid Requate 2017-08-28 19:15:53 CEST

A customer reported that windows clients could not be joined with his UCS@school Slave PDC if the client machine object had not been created manually beforehand.

The error message was misleading the customer (or professional service) to believe that something was wrong with the RID Pool or so. Bug log.samba shows that it was actually a UMC connection failing due to a certificate issue:
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[2017/08/23 13:01:52.732651,  1, pid=27714] ../lib/ldb-samba/ldb_wrap.c:76(ldb_wrap_debug)
  ldb: univention_samaccountname_ldap_check: calling ucs-school-create_windows_computer
  
Traceback (most recent call last):
  File "/usr/sbin/ucs-school-create_windows_computer", line 77, in <module>
    main()
  File "/usr/sbin/ucs-school-create_windows_computer", line 62, in main
    client = Client(args.server, args.username, args.password)
  File "/usr/lib/pymodules/python2.7/univention/lib/umc.py", line 242, in __init__
    self.authenticate(username, password)
  File "/usr/lib/pymodules/python2.7/univention/lib/umc.py", line 250, in authenticate
    return self.umc_auth(username, password)
  File "/usr/lib/pymodules/python2.7/univention/lib/umc.py", line 286, in umc_auth
    return self.request('POST', 'auth', data)
  File "/usr/lib/pymodules/python2.7/univention/lib/umc.py", line 297, in request
    return self.send(request)
  File "/usr/lib/pymodules/python2.7/univention/lib/umc.py", line 312, in send
    raise ConnectionError('Could not send request.', reason=exc)
univention.lib.umc.ConnectionError: ('Could not send request.', CertificateError("hostname 'master.ucs.school' doesn't match either of 'portal.ucs.school', 'portal'",))
[2017/08/23 13:01:54.160896,  1, pid=10915] ../lib/ldb-samba/ldb_wrap.c:76(ldb_wrap_debug)
  ldb: univention_samaccountname_ldap_check: LDB_ERR_ENTRY_ALREADY_EXISTS
  
[2017/08/23 13:01:54.161120,  0, pid=10915] ../source4/dsdb/common/util_samr.c:184(dsdb_add_user)
  Failed to create user record CN=CLIENMAME,CN=Computers,DC=ucs,DC=school: ldb_request: Entry already exists (68)
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We should check if we can return a less misleading generic error code.