Problem: "Value already exists" when adding a user to a workgroup

[fdavid]

Problem

When trying to add a new user to a workgroup, the process fails with the error message:

Type or value exists: modify/add: uniqueMember: value #1 already exists

In the logs it becomes clear that, besides the newly selected user, two additional users are being re-added to the group—even though they were not selected and are already members.

Example log excerpt:

mod dn=cn=workgroup1,... err={'desc': 'Type or value exists', 'info': 'modify/add: uniqueMember: value #1 already exists'}

Cause

The affected users (in this example: user3 and user6) already exist as group members, but with a slightly different Distinguished Name (DN).

• Current group entries:

  uid=user3,...,ou=s109,dc=ucs,dc=test,dc=schule
  uid=user6,...,ou=s109,dc=ucs,dc=test,dc=schule
  

• Actual correct DNs:

  uid=user3,...,ou=S109,dc=ucs,dc=test,dc=schule
  uid=user6,...,ou=S109,dc=ucs,dc=test,dc=schule
  

The only difference is the case sensitivity of the OU (s109 vs. S109).
The module detects this mismatch and tries to “correct” the entries, but the LDAP modification fails because the users are already listed—just with the lowercase OU.

This behavior is a known issue documented in Univention Bug 58563.

Solution

To resolve the issue:

1. Remove the affected users (with the incorrect DN) from the workgroup.
2. Re-add them to the group.

This ensures that the uniqueMember attributes are stored with the correct DN (ou=S109), avoiding duplicate/conflicting entries.

Example before and after

Before (incorrect):

uniqueMember: uid=user3,cn=lehrer und mitarbeiter,cn=users,ou=s109,dc=ucs,dc=test,dc=schule
uniqueMember: uid=user6,cn=lehrer und mitarbeiter,cn=users,ou=s109,dc=ucs,dc=test,dc=schule

After (fixed):

uniqueMember: uid=user3,cn=lehrer und mitarbeiter,cn=users,ou=S109,dc=ucs,dc=test,dc=schule
uniqueMember: uid=user6,cn=lehrer und mitarbeiter,cn=users,ou=S109,dc=ucs,dc=test,dc=schule