Openstack中keystone与外部LDAP Server的集成
https://www.cnblogs.com/bjtime/p/9951929.html
详情参见官网：
https://docs.openstack.org/keystone/rocky/admin/identity-domain-specific-config.html
https://docs.openstack.org/keystone/rocky/configuration.html (Configuring Keystone)
https://developer.openstack.org/