Use pkexec instead of gksudo for adding users to group.

Use pkexec instead of gksudo for adding users to group.

gksudo is deprecated on Ubuntu and unavailable on some other distros.
Under this change, linux_me2me_host.py reexecutes itself as root (via
sudo or pkexec) to handle adding users to the chrome-remote-desktop
group. Unlike gksudo, pkexec does not allow showing the user a custom
message without installing a PolicyKit policy. Instead, the user will
see a message like:

Authentication is needed to run
`/opt/google/chrome-remote-desktop/chrome-remote-desktop' as the super
user

While we may want to add a PolicyKit policy in the future, hopefully
this message is sufficiently clear about what triggered the password
prompt for now.

BUG=342210
Committed: https://crrev.com/51e4d20a8699a245daa4a6548834751aa1339aff
Cr-Commit-Position: refs/heads/master@{#320196}

[rickyz (no longer on Chrome), 2015-02-09 01:57:26]

rickyz@chromium.org changed reviewers:
+ sergeyu@chromium.org

[rickyz (no longer on Chrome), 2015-02-09 01:57:27]

Hey, as I mentioned on crbug.com/343329, I'm looking at making some of the
changes needed to support Chrome Remote Desktop on distros other than
Ubuntu/Debian, so here's a change to switch from gksudo to pkexec.

[Sergey Ulanov, 2015-02-09 22:00:25]

Thanks for working on this!

One issue with Polkit is its behavior with non-standard desktop environment.
E.g. I use fluxbox on my desktop and for some reason pkexec tries to
authenticate in the console (which is not visible unless I start chrome from a
terminal). If I have Unity running on the same machine in a CRD session then
authentication prompt is shown there. Do you know if there is a way to
workaround such cases? E.g. can we detect that polkit is configured properly for
the current X session and try using gksudo otherwise?

In the same time what you implemented in this CL should for majority of users,
so LGTM.

https://codereview.chromium.org/907783002/diff/1/remoting/host/linux/linux_me...
File remoting/host/linux/linux_me2me_host.py (right):

https://codereview.chromium.org/907783002/diff/1/remoting/host/linux/linux_me...
remoting/host/linux/linux_me2me_host.py:1104: command = ["/usr/bin/pkexec"] +
command
add TODO to add Polkit policy

[Lambros, 2015-02-09 23:12:45]

lambroslambrou@chromium.org changed reviewers:
+ lambroslambrou@chromium.org

[Lambros, 2015-02-09 23:12:46]

Thanks for doing this work. Do you know if pkexec works correctly in Ubuntu
12.04 (Precise)? I can't remember if the pkexec tool is able to show a graphical
prompt on that system?

[Lambros, 2015-02-09 23:25:36]

On 2015/02/09 23:12:46, Lambros wrote:
> Thanks for doing this work. Do you know if pkexec works correctly in Ubuntu
> 12.04 (Precise)? I can't remember if the pkexec tool is able to show a
graphical
> prompt on that system?

Also, please update the Depends: section in
remoting/host/installer/linux/debian/control
to remove "gksu" and add "policykit-1".

[rickyz (no longer on Chrome), 2015-02-13 05:03:40]

New patchsets have been uploaded after l-g-t-m from sergeyu@chromium.org

[rickyz (no longer on Chrome), 2015-02-13 05:03:52]

https://codereview.chromium.org/907783002/diff/1/remoting/host/linux/linux_me...
File remoting/host/linux/linux_me2me_host.py (right):

https://codereview.chromium.org/907783002/diff/1/remoting/host/linux/linux_me...
remoting/host/linux/linux_me2me_host.py:1104: command = ["/usr/bin/pkexec"] +
command
On 2015/02/09 22:00:25, Sergey Ulanov wrote:
> add TODO to add Polkit policy

Done.

[Sergey Ulanov, 2015-03-11 23:42:21]

Can this be landed now? Is there anything blocking this CL?

[rickyz (no longer on Chrome), 2015-03-11 23:55:58]

On 2015/03/11 23:42:21, Sergey Ulanov wrote:
> Can this be landed now? Is there anything blocking this CL?

Thank you for the reminder - CQing :-)

[rickyz (no longer on Chrome), 2015-03-11 23:56:04]

The CQ bit was checked by rickyz@chromium.org

[commit-bot: I haz the power, 2015-03-11 23:57:36]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/907783002/20001

[commit-bot: I haz the power, 2015-03-12 01:06:25]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2015-03-12 01:07:14]

Patchset 2 (id:??) landed as
https://crrev.com/51e4d20a8699a245daa4a6548834751aa1339aff
Cr-Commit-Position: refs/heads/master@{#320196}