Install ca-certificates on GCE

Needed to fetch GCE startup scripts over HTTPS, among other reasons.

Change-Id: I89e3afb44f786539b5e3275b5f1f3b7201ab44fd
Merge pull request #126 from jkaplowitz/development

Install ca-certificates on GCE
Installing Cloud SDK which includes gcutil and gsutil. We still don't
have a package for it so laying out the tarball for now.

Change-Id: If66f0f1c074e6077e1ca57375cac9c4832bbd7fc
Merge pull request #131 from jkaplowitz/cloudsdk

Install Cloud SDK, which includes gcutil and gsutil.
Reinstate hostname hook for GCE

This DHCP exit hook to shorten the system hostname on GCE was previously
installed by build-debian-cloud and bootstrap-vz, but seems to have been
inadvertently removed in commit c81045cc6e0f6a2c90002ab50219a15c337630f1
as part of a broad cross-cloud cleanup. Again, this was caught by our
validation tests, and we might be done with the fixes at this point.

In this commit, I'm reinstating the hook with a name change and an
explanatory comment, to reduce the risk of this vanishing accidentally
in the future.

Change-Id: I4e7268f8b9ab3b2a7fc8b510898c6fbdd685aa53
Merge pull request #134 from jkaplowitz/hostname-fix

Reinstate hostname hook for GCE
Disable SSH password auth on GCE

This change was unintentional but occurred as part of GCE's transition
from build-debian-cloud to bootstrap-vz.

Might be replaced later with a similar change that applies to all
bootstrap-vz providers, based on the opinion of the debian-cloud list.

Change-Id: I72a694c49f32df06252d9cc01b1d5c7cfc015347
Removed a check to verify file type

The file command is not installed by bootstrap-vz by default.

Change-Id: I59d5f04145b7db517c28bfec1d4d758be468b398
Merge pull request #138 from jkaplowitz/development

Fix two issues that were uncovered by GCE's 20140807 image
Support --color option to indicate whether to use colors in the terminal

Mimic the behavior of the --color=<auto|always|never> found in tools
like `ls' and `grep'. Default to `auto' which checks whether stderr is a
tty to define whether colors are used.

Tested:
- Ran ./boostrap-vz --color=never and --color=always, confirmed
  colorization worked as expected.
- Ran ./boostrap-vz --color=auto ${manifest_file} 2>bootstrap.log,
  confirmed colors were not added to boostrap.log by default, repeated
  the test with --color=always and confirmed escape sequences were
  output.

Signed-off-by: Filipe Brandenburger <filbranden@google.com>
Check the value of the --color argument

Make sure it's either `auto' (the default), `always' or `never'. If it
does not match any of the values, raise a Docopt exception that causes
it to print usage and exit.

Tested:
- $ sudo ./bootstrap-vz --color=invalid manifests/gce.manifest.yml
  Value of --color must be one of auto, always or never.
  Usage: bootstrap-vz [options] MANIFEST

Signed-off-by: Filipe Brandenburger <filbranden@google.com>
Merge pull request #143 from filbranden/color_when

Support --color option to indicate whether to use colors in the terminal