Hello all,
Recently I tried installing Openstack via this guide. Upon completion of all the steps including the dashboard step, I was greeted with this error inside the nova_schedular.log file, after I tried creating an instance.

2103 ERROR oslo.messaging._drivers.impl_rabbit Connection failed: failed to resolve broker hostname: OSError: failed to resolve broker hostname

When I try to create an instance it hangs in the "scheduling" state and throws this error. I have not configured anything in the "oslo.messaging" section of the Nova config file. I believe that under the [default] section this is what's causing the issue, but the password and hostname are fine. 

transport_url = rabbit://openstack:BnE9LLfCtjdPvpEnZUnPytSyrfUxE8th@controller

Thanks!