There should be a possibility to access the network manager information such as DNS Server, Search Domain and Domain Name via environment variables. If the application inside the container needs to communicate within the local network, DNS is the only possibility to make this happen in a dynamic way.
At the moment every container application needs to have nmcli installed to be able to access this information. Other alternatives are ugly workarounds.
There was already a ticket Request #5103 for that topic created.