tree fb938b90b55e1f915d12f4e099a40ba33930e1fb
parent 93db6a8c7526082cf1c8091fa90b55ca99d9b669
author Jamie Lennox <jamielennox@gmail.com> 1489643285 +1100
committer Jamie Lennox <jamielennox@gmail.com> 1492574385 +1000

Re-add the ability to set username on zuul-executor

Sometimes we need to log in to a nodepool node using a username of
something other than zuul. This used to be possible by setting that
[launcher] username= property. Re-enable it with the [executor]
default_username= property.

default_username is used instead of simply username as it is likely in
future this information will be able to be supplied by nodepool or other
in a node or image specific way. At which time that information will be
used in priority to the default specified in zuul.

Change-Id: Icf657b4f0bbe34e182307b9eea0cd64a8d813464