LDAP search with custom attributes filter - ldap

Question

I'm having problems with finding a specific entry in LDAP tree, given a filter defined on a custom attribute.
I.e. (search by samaccountname=jpa)
ldapsearch -x -D "CN=admin,DC=my,DC=com" -w admin -H ldap://localhost:10389 -b "ou=My Users,dc=my,dc=com" -s sub "samaccountname=jpa" does not work (returns no result)
whereas (search sn=jpa):
ldapsearch -x -D "CN=admin,DC=my,DC=com" -w admin -H ldap://localhost:10389 -b "ou=My Users,dc=my,dc=com" -s sub "sn=jpa" works
even (check for existence of samaccountname):
ldapsearch -x -D "CN=admin,DC=my,DC=com" -w admin -H ldap://localhost:10389 -b "ou=My Users,dc=my,dc=com" -s sub "samaccountname=*" works
Any ideas what can be wrong here? My intention is to find the given user using sub (samaccountname=jpa) filter
My config is (using osixia/openldap docker image):
schema:
attributetype ( 1.2.840.113556.1.4.221 NAME 'sAMAccountName'
SYNTAX 1.3.6.1.4.1.1466.115.121.1.15
SINGLE-VALUE
USAGE userApplications )
objectclass ( 2.5.6.30 NAME 'extendedUser'
SUP person
STRUCTURAL
MUST ( sAMAccountName ) )
ACL's:
dn: olcDatabase={1}mdb,cn=config
changetype: modify
delete: olcAccess
-
add: olcAccess
olcAccess: to * by * read
LDIF:
DN: OU=My Users,DC=my,DC=com
OU: My Users
objectClass: organizationalUnit
DN: CN=jpa,OU=My Users,DC=my,DC=com
CN: jpa
sn: jpa
sAMAccountName: jpa
objectClass: extendedUser
userPassword: xxx

Answer 1

You need to define an EQUALITY on your attribute. LDAP doesn't currently know how to perform the search on that attribute.
attributetype ( 1.2.840.113556.1.4.221 NAME 'sAMAccountName'
SYNTAX 1.3.6.1.4.1.1466.115.121.1.15
EQUALITY caseIgnoreMatch
SINGLE-VALUE
USAGE userApplications )
OpenLDAP Schema Specification