I'm testing Keycloak LDAP User Federation with FreeIPA iDM Server.
I'm using the same environment used by @mposolda [1] with the @adelton's FreeIPA Docker container image [2].
The
integration (KC and FreeIPA) worked fine except for the sync for new
users created on KC side (new registrations). When I enable the 'Sync
Registrations' on the 'freeipa-ldap' User Federation and then try to add
a new user using the KC Web Console I get the following error:

KC server.log in TRACE mode:
"
2016-06-11 22:33:37,568 TRACE [org.keycloak.models.cache.infinispan.RealmCacheSession] (default task-5) realm by name cache hit: master
2016-06-11 22:33:37,568 TRACE [org.keycloak.models.cache.infinispan.RealmCacheSession] (default task-5) by id cache hit: master
2016-06-11
22:33:37,569 DEBUG [org.keycloak.services] (default task-5) token
active - active: true, issued-at: 1,465,684,397, not-before: 0
2016-06-11 22:33:37,569 TRACE [org.keycloak.models.cache.infinispan.UserCacheSession] (default task-5) getuserById 6f358dd3-3c20-4a84-b0b5-b02c77747a5a
2016-06-11 22:33:37,569 TRACE [org.keycloak.models.cache.infinispan.UserCacheSession] (default task-5) returning new cache adapter
2016-06-11 22:33:37,569 TRACE [org.keycloak.models.cache.infinispan.RealmCacheSession] (default task-5) client by name cache hit: security-admin-console
2016-06-11 22:33:37,569 TRACE [org.keycloak.models.cache.infinispan.RealmCacheSession] (default task-5) client by id cache hit: security-admin-console
2016-06-11 22:33:37,569 DEBUG [org.keycloak.services] (default task-5) authenticated admin access for: admin
2016-06-11 22:33:37,569 DEBUG [org.keycloak.services] (default task-5) No origin returning
2016-06-11 22:33:37,569 TRACE [org.keycloak.models.cache.infinispan.RealmCacheSession] (default task-5) realm by name cache hit: freeipa
2016-06-11 22:33:37,569 TRACE [org.keycloak.models.cache.infinispan.RealmCacheSession] (default task-5) by id cache hit: freeipa
2016-06-11 22:33:37,569 TRACE [org.keycloak.models.cache.infinispan.RealmCacheSession] (default task-5) by id cache hit: master
2016-06-11 22:33:37,569 TRACE [org.keycloak.models.cache.infinispan.RealmCacheSession] (default task-5) by id cache hit: master
2016-06-11 22:33:37,569 TRACE [org.keycloak.models.cache.infinispan.RealmCacheSession] (default task-5) by id cache hit: master
2016-06-11 22:33:37,569 TRACE [org.keycloak.models.cache.infinispan.RealmCacheSession] (default task-5) client by id cache hit: freeipa-realm
2016-06-11 22:33:37,569 TRACE [org.keycloak.models.cache.infinispan.RealmCacheSession] (default task-5) getClientRoles cache hit: freeipa-realm
2016-06-11 22:33:37,570 TRACE [org.keycloak.models.cache.infinispan.RealmCacheSession] (default task-5) getClientRoles cache hit: freeipa-realm
2016-06-11 22:33:37,570 TRACE [org.keycloak.models.cache.infinispan.UserCacheSession] (default task-5) getUserByUsername: kc_user1
2016-06-11 22:33:37,570 TRACE [org.keycloak.models.cache.infinispan.UserCacheSession] (default task-5) query null
2016-06-11 22:33:37,571 TRACE [org.keycloak.models.cache.infinispan.UserCacheSession] (default task-5) model from delegate null
2016-06-11 22:33:37,571 TRACE [org.keycloak.federation.ldap.idm.store.ldap.LDAPIdentityStore] (default task-5) Using filter for LDAP search: (&(uid=kc_user1)(objectclass=person)) . Searching in DN: cn=users,cn=accounts,dc=example,dc=test
2016-06-11 22:33:37,575 TRACE [org.keycloak.federation.ldap.idm.store.ldap.LDAPIdentityStore] (default task-5) Using filter for LDAP search: (&(mail=kc_user1@example.test)(objectclass=person)) . Searching in DN: cn=users,cn=accounts,dc=example,dc=test
2016-06-11 22:33:37,577 TRACE [org.keycloak.models.cache.infinispan.RealmCacheSession] (default task-5) getRealmRoles cache hit: freeipa
2016-06-11 22:33:37,578 TRACE [org.keycloak.models.cache.infinispan.RealmCacheSession] (default task-5) getClients cache hit: freeipa
2016-06-11 22:33:37,578 TRACE [org.keycloak.models.cache.infinispan.RealmCacheSession] (default task-5) client by id cache hit: broker
2016-06-11 22:33:37,578 TRACE [org.keycloak.models.cache.infinispan.RealmCacheSession] (default task-5) client by id cache hit: realm-management
2016-06-11 22:33:37,578 TRACE [org.keycloak.models.cache.infinispan.RealmCacheSession] (default task-5) client by id cache hit: liferay-saml-idp
2016-06-11 22:33:37,578 TRACE [org.keycloak.models.cache.infinispan.RealmCacheSession] (default task-5) client by id cache hit: security-admin-console
2016-06-11 22:33:37,578 TRACE [org.keycloak.models.cache.infinispan.RealmCacheSession] (default task-5) client by id cache hit: kitchensink
2016-06-11 22:33:37,579 TRACE [org.keycloak.models.cache.infinispan.RealmCacheSession] (default task-5) client by id cache hit: admin-cli
2016-06-11 22:33:37,579 TRACE [org.keycloak.models.cache.infinispan.RealmCacheSession] (default task-5) client by id cache hit: account
2016-06-11 22:33:37,579 TRACE [org.keycloak.models.cache.infinispan.RealmCacheSession] (default task-5) getClientRoles cache hit: account
2016-06-11 22:33:37,580 TRACE [org.keycloak.models.cache.infinispan.RealmCacheSession] (default task-5) getClientRoles cache hit: account
2016-06-11 22:33:37,581 TRACE [org.keycloak.federation.ldap.idm.store.ldap.LDAPOperationManager] (default task-5) Creating entry [uid=kc_user1,cn=users,cn=accounts,dc=example,dc=test] with attributes: [
2016-06-11 22:33:37,583 TRACE [org.keycloak.federation.ldap.idm.store.ldap.LDAPOperationManager] (default task-5) objectclass = person
2016-06-11 22:33:37,583 TRACE [org.keycloak.federation.ldap.idm.store.ldap.LDAPOperationManager] (default task-5) givenname =
2016-06-11 22:33:37,583 TRACE [org.keycloak.federation.ldap.idm.store.ldap.LDAPOperationManager] (default task-5) sn =
2016-06-11 22:33:37,583 TRACE [org.keycloak.federation.ldap.idm.store.ldap.LDAPOperationManager] (default task-5) cn =
2016-06-11 22:33:37,583 TRACE [org.keycloak.federation.ldap.idm.store.ldap.LDAPOperationManager] (default task-5) ]
2016-06-11
22:33:37,607 ERROR [io.undertow.request] (default task-5) UT005023:
Exception handling request to /auth/admin/realms/freeipa/users: org.jboss.resteasy.spi.UnhandledException: org.keycloak.models.ModelException: Error creating subcontext [uid=kc_user1,cn=users,cn=accounts,dc=example,dc=test]
at org.jboss.resteasy.core.ExceptionHandler.handleApplicationException(ExceptionHandler.java:76)
at org.jboss.resteasy.core.ExceptionHandler.handleException(ExceptionHandler.java:212)
at org.jboss.resteasy.core.SynchronousDispatcher.writeException(SynchronousDispatcher.java:168)
... 37 more
Caused by: javax.naming.directory.SchemaViolationException: [LDAP: error code 65 - attribute "uid" not allowed
]; remaining name 'uid=kc_user1,cn=users,cn=accounts,dc=example,dc=test'
at com.sun.jndi.ldap.LdapCtx.mapErrorCode(LdapCtx.java:3166)
at com.sun.jndi.ldap.LdapCtx.processReturnCode(LdapCtx.java:3081)
at com.sun.jndi.ldap.LdapCtx.processReturnCode(LdapCtx.java:2888)
at com.sun.jndi.ldap.LdapCtx.c_createSubcontext(LdapCtx.java:812)
at com.sun.jndi.toolkit.ctx.ComponentDirContext.p_createSubcontext(ComponentDirContext.java:341)
at com.sun.jndi.toolkit.ctx.PartialCompositeDirContext.createSubcontext(PartialCompositeDirContext.java:268)
at com.sun.jndi.toolkit.ctx.PartialCompositeDirContext.createSubcontext(PartialCompositeDirContext.java:256)
at javax.naming.directory.InitialDirContext.createSubcontext(InitialDirContext.java:197)
at javax.naming.directory.InitialDirContext.createSubcontext(InitialDirContext.java:197)
at org.keycloak.federation.ldap.idm.store.ldap.LDAPOperationManager$7.execute(LDAPOperationManager.java:434)
at org.keycloak.federation.ldap.idm.store.ldap.LDAPOperationManager$7.execute(LDAPOperationManager.java:431)
at org.keycloak.federation.ldap.idm.store.ldap.LDAPOperationManager.execute(LDAPOperationManager.java:536)
at org.keycloak.federation.ldap.idm.store.ldap.LDAPOperationManager.createSubContext(LDAPOperationManager.java:431)
... 57 more"
FreeIPA Server ldap srv log:
""
tail -f /data/var/log/dirsrv/slapd-EXAMPLE-TEST/errors
[11/Jun/2016:22:33:37 +0000] - Entry "uid=kc_user1,cn=users,cn=accounts,dc=example,dc=test" -- attribute "uid" not allowed
""
----
It appears FreeIPA LDAP server is refusing the attribute 'UID'
Interesting is that the FreeIPA 'user_add' API operation states the 'uid' attributes is required: