I need to apologize.
I was/am fully aware of that extra_config file but may have forgotten completely that it seems this file was also manually edited by me a long time ago. (I have another line inside about hosts.editable which is not of use. So I really thought that mounting of /system/etc/hosts to etc/hosts is part of aliendalvik package). And to be honest I expected this to be part of the aliendalvik package!
But a rpm -qf /var/lib/lxc/extra_config tells me this is not part of any package
I will also create a feature request but do not expect that to be noticed or implemented within the next few releases, month/years.
For that reason I will add this extra_config file to the harbour-defender package (may take some time because it needs a bit of testing).
Meanwhile you may use
to differentiate between native etc/hosts and the Android system/etc/hosts (there may be reasons to do so), preferred for harbour-defender users:
echo 'lxc.mount.entry = **/system**/etc/hosts system/etc/hosts none bind,ro 0 0' >> /var/lib/lxc/aliendalvik/extra_config
or to just simply use /etc/hosts for both environments ( not using harbour-defender maybe ):
echo 'lxc.mount.entry = /etc/hosts system/etc/hosts none bind,ro 0 0' >> /var/lib/lxc/aliendalvik/extra_config
the create_file option is not needed as system/etc/hosts file is part of system.img
and I added the ro option to not allow the dark side to alter files on native file system