commit d2188b76212d8aae675936042a7b13e45f46bb9d
author Bogdan Caprita <caprita@google.com> Fri May 22 12:31:48 2015 -0700
committer Bogdan Caprita <caprita@google.com> Fri May 22 12:32:02 2015 -0700
tree cf53f217e11b2bcafc35d29f73335149c2aac6dd
parent 06c85efe016e08d07909526dd716d3aa8eeef267

services/device/device: globify the update command

Remove the old cmdUpdate and cmdUpdateAll, and add a shiny new cmdUpdate in its
own file (update.go) that uses the glob support. The implementation borrows code
from what used to be updateall.go: instanceIsRunning() is mostly unchanged;
updateInstance() and updateInstallation() are altered (dare I say improved and
simplified).

Also add a unit test which previously didn't exist.

Supporting changes to glob.go:

add context to globHandler (needed if the handler is to make RPCs)

add flag to control handler parallelism; three modes are supported:
1. all handlers are run in parallel
2. all handlers are run sequentially, according to the sort order
3. run all installation handlers first (in parallel), then run all instance
handlers (in parallel)
Modes 2. and 3. are useful for the update command (where we may want more
control on the order of the updates, e.g. do installation before instance)

change the error reporting strategy: the errors from handlers are printed to the
stderr buffer for the respective handler (to ensure grouping with any other
stderr output in the handler); the run() method itself only returns a summary of
the number of errors encountered.

add device service as an option besides installation and instance (since the
device service object occasionally acts like an instance and other times like an
installation); also, we want to sort it deterministically in the glob results.

MultiPart: 2/2

Change-Id: I483255b522295e7de06facdfab0e5b29a4cc0bd1