Empty hostname in VM

[mateuszsrebrny]

Our VMs seem to have an empty hostname.

It is a problem when you want to run a code that tries to use this hostname :)
For example on Ray documentation site there is a super easy example code that runs tasks on a couple of workers and then uses python socket.gethostbyname(socket.gethostname()) to print how many tasks it executed on which worker. This code segfaults. We know it, and we can fix (either the app or our requestor), but it might be super confusing for people trying their stuff.

IIUC docker sets hostname for its vms for container id - so if we don't it is an incompatibility.

I don't know how problematic it is in general, in Ray on Golem we will set the hostname manually after the VM is up, but maybe it would be prudent to set the hostname at least to something that doesn't segfault your app :)

[mateuszsrebrny]

@shadeofblue believes that even without fixing deserves a mention in the documentation (where we describe docker vs VM differences) and maybe example showing how to set the hostname manually :)

[mateuszsrebrny]

A note about workaround:
You can set hostname manually using run command. https://www.redhat.com/sysadmin/configure-hostname-linux