enter_chroot: Only mount SSH auth socket when we need to.

enter_chroot: Only mount SSH auth socket when we need to.

Also refactors some cut-and-paste code

BUG=11944
TEST=enter_chroot.sh with and without another enter_chroot running.  Note that there are 0 or 1 mounts of the /tmp/ssh-.... directory.  Check that /proc,/sys,/dev,$SSH_AUTH_SOCK,/dev/pts,/home/${USER}/trunk,/home/${USER}/.subversion are all mounted

Change-Id: I9dada6f7f98d263345af29a5734c1c70709f6a1e

Committed: http://chrome-svn/viewvc/chromeos?view=rev&revision=abaf1cc

[Elly Fong-Jones, 2011-02-11 14:59:19]

LGTM. Can anush or someone that understands enter_chroot take a look at this
too?

[rochberg, 2011-02-11 15:23:45]

On 2011/02/11 14:59:19, Elly Jones wrote:
> LGTM. Can anush or someone that understands enter_chroot take a look at this
> too?

Don:  Can you take a look too?  Thanks.

[dgarrett, 2011-02-11 21:07:50]

LGTM with a couple of small nits.

Over all, looks better and cleaner. Thanks!

http://codereview.chromium.org/6498001/diff/1/enter_chroot.sh
File enter_chroot.sh (right):

http://codereview.chromium.org/6498001/diff/1/enter_chroot.sh#newcode143
enter_chroot.sh:143: local mounted_path="$(readlink -f
"${FLAGS_chroot}/$target")"
Can't this line be redone as:

local mounted_path="$(readlink -f ${FLAGS_chroot}/${target})"

???

http://codereview.chromium.org/6498001/diff/1/enter_chroot.sh#newcode145
enter_chroot.sh:145: if [ -z "$(mount | grep -F "on $mounted_path ")" ]; then
I believe we are supposed to use ${mounted_path} instead of $mounted_path.

[rochberg, 2011-02-11 22:28:56]

(haven't yet pushed or uploaded---will do that when I'm around to pick up the
pieces if something goes wrong)

http://codereview.chromium.org/6498001/diff/1/enter_chroot.sh
File enter_chroot.sh (right):

http://codereview.chromium.org/6498001/diff/1/enter_chroot.sh#newcode143
enter_chroot.sh:143: local mounted_path="$(readlink -f
"${FLAGS_chroot}/$target")"
On 2011/02/11 21:07:50, dgarrett wrote:
> Can't this line be redone as:
> 
> local mounted_path="$(readlink -f ${FLAGS_chroot}/${target})"
> 
> ???

The extra level of quoting is necessary if FLAGS_chroot has a space in it.   Did
I mention I hate the shell?

http://codereview.chromium.org/6498001/diff/1/enter_chroot.sh#newcode145
enter_chroot.sh:145: if [ -z "$(mount | grep -F "on $mounted_path ")" ]; then
On 2011/02/11 21:07:50, dgarrett wrote:
> I believe we are supposed to use ${mounted_path} instead of $mounted_path.

We are.  Done.

[dgarrett, 2011-02-12 00:39:45]

It's good.

http://codereview.chromium.org/6498001/diff/1/enter_chroot.sh
File enter_chroot.sh (right):

http://codereview.chromium.org/6498001/diff/1/enter_chroot.sh#newcode143
enter_chroot.sh:143: local mounted_path="$(readlink -f
"${FLAGS_chroot}/$target")"
I think what happens to the quotes inside the $() confused me. You're right.