Operating system: Archlinux
Python version: 3.8.5
python-ldap version: 3.3.0

I wrote a custom schema and I would like to write some tests using this schema.

I can manage to do this by copying or linking my schema files in SlapdObject.SCHEMA_DIR before the process is launched. However this is not convenient at all (see next comment).

The ldapadd command cannot add schemas:

RuntimeError: ['/usr/bin/ldapadd', '-H', 'ldapi://%2Fhome%2Feloi%2Fdev%2Fyaal%2Foidc-ldap-bridge%2Fpython-ldap-test-52629%2Fldapi', '-Y', 'EXTERNAL', '-Q'] process failed:
b'adding new entry "cn=oauth,cn=schema,cn=config"\n\n'
b'ldap_add: Insufficient access (50)\n'

However, the slapadd command could. I suggest to implement a SlapdObject.slapadd method, similar to SlapdObject.ldapadd. This would allow to call slapadd -l myschema.ldif -n0 (-n0 being an option, that could be used to add the schema in the config database). This way, one could add a schema to the slapd server test after it is started.

If ldapadd seems too much, maybe we can just find a mechanism to simply add custom schemas by configuring or passing parameters to SlapdObject?

If you are ok with this, I can provide a patch.
What do you think?