This bug is created as a clone of upstream ticket:
https://fedorahosted.org/freeipa/ticket/6138



When SSSD resolves AD users on behalf of slapi-nis, it can accept any user identifier, including user principal name (UPN) which may be different than the canonical user name which SSSD returns.

As result, the entry created by slapi-nis will be using canonical user name but the filter for search will refer to the original (aliased) name. The search will not match the newly created entry.

The issue can be fixed by returning two values for 'uid' attribute: the canonical one and the aliased one. This way the search will match. This is what ticket https://fedorahosted.org/slapi-nis/ticket/12 will do on slapi-nis side.

On FreeIPA side an update is needed to cn=users,cn=compat,$suffix definition to allow multiple 'uid' values because RDN generation function expects a single value of 'uid' attribute.

A change is to add explicit 'uid' attribute generation and change rdn processing to use %first() function:
{{{
dn: cn=users,cn=Schema Compatibility,cn=plugins,cn=config
cn: users
objectClass: top
objectClass: extensibleObject
schema-compat-container-group: cn=compat, dc=ipa,dc=ad,dc=test
schema-compat-container-rdn: cn=users
schema-compat-entry-attribute: %ifeq("ipaanchoruuid","%{ipaanchoruuid}","objectclass=ipaOverrideTarget","")
schema-compat-entry-attribute: cn=%{cn}
schema-compat-entry-attribute: objectclass=posixAccount
schema-compat-entry-attribute: gidNumber=%{gidNumber}
schema-compat-entry-attribute: gecos=%{cn}
schema-compat-entry-attribute: ipaanchoruuid=%{ipaanchoruuid}
schema-compat-entry-attribute: %ifeq("ipauniqueid","%{ipauniqueid}","ipaanchoruuid=:IPA:ipa.ad.test:%{ipauniqueid}","")
schema-compat-entry-attribute: uidNumber=%{uidNumber}
schema-compat-entry-attribute: %ifeq("ipauniqueid","%{ipauniqueid}","objectclass=ipaOverrideTarget","")
schema-compat-entry-attribute: loginShell=%{loginShell}
schema-compat-entry-attribute: homeDirectory=%{homeDirectory}
schema-compat-entry-attribute: uid=%{uid}
schema-compat-entry-rdn: uid=%first("%{uid}")
schema-compat-ignore-subtree: cn=dna,cn=ipa,cn=etc,$SUFFIX
schema-compat-restrict-subtree: cn=Schema Compatibility,cn=plugins,cn=config
schema-compat-restrict-subtree: $SUFFIX
schema-compat-search-base: cn=users, cn=accounts, $SUFFIX
schema-compat-search-filter: objectclass=posixAccount
schema-compat-lookup-nsswitch: user
}}}