Thinking of how best to handle dynamic cluster deployment where no machine knows its hostname until deployed.

I've proposed a function to do this, a hostname() operation, but the other way is just to have the Hadoop Services explicitly do this -as an option.

something like :

conf.useLocalHostname

and we'd get the localhost (this could be cached somewhere BTW) and then fill in a new fs.default.name from the existing URL, replacing the hostname field.