Set virtualenv and path in defaults file
Set virtualenv and path in defaults file

Nodepool calls out to diskimage builder based on PATH which is a fixed
value in systemd. Unfortunately you can't expand existing environment
variables in a unit file so you can't just set PATH=/venv:$PATH we have
to specify the whole thing. At least systemd defines a specific constant
PATH [1] so we can safely extend it.

The better fix here would be for nodepool to call dib via like python
`which disk-image-builder`.

[1] https://www.freedesktop.org/software/systemd/man/systemd.exec.html#Environment%20variables%20in%20spawned%20processes

BonnyCI/hoist,jamielennox/hoist,SpamapS/hoist,SpamapS/hoist,jamielennox/hoist,BonnyCI/hoist