Add a script to kick off worker from a GCE instance.

This is modelled closely on the purge_gs.sh script from chromite and
will be used similarly from a GCE instance.

The script launches the worker once, using the password provided via GCE
instance metadata attributes. It then sleeps for 2-4 hours and finally
exits. Upon exit, the instance is expected to reboot, restarting the
whole process.

BUG=chromium:724619
TEST=None (yet).

Change-Id: Iebe430256444d9c419a2851f379365a714ec26c2
Reviewed-on: https://chromium-review.googlesource.com/513483
Reviewed-by: Prathmesh Prabhu <pprabhu@chromium.org>
Tested-by: Prathmesh Prabhu <pprabhu@chromium.org>
2 files changed