vmlinuz not found during server ISO validation

[Para Siva]

The latest static validation tests for raring server amd64 (20121207) are
failing because the vmlinuz is not found.

The failure seen is as below.

FAIL: test_vmlinuz (__main__.TestValidateISO)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/usr/share/utah/isotest/iso_static_validation.py", line 348, in test_vmlinuz
    self.assertIn("Linux kernel", stdout)
AssertionError: 'Linux kernel' not found in "/tmp/tmp2nkThz/./install/vmlinuz: ERROR: cannot open `/tmp/tmp2nkThz/./install/vmlinuz' (No such file or directory)\n"

The job that's affected is
https://jenkins.qa.ubuntu.com/view/Raring/view/Smoke%20Testing/job/raring-server-amd64-smoke-default/24/

Since this job triggers the rest of the amd64 server tests, all 16 tests have
not run for 20121207 amd64 server image.

This might be a regression due to the fix for bug 1086772 which should have
maintained the earlier case of skipping for d-i based images.

[Javier Collado (javier.collado)]

What I see in the image is that there's a file:
/install/vmlinuz

that's a hard link to:
/install/netboot/ubuntu-installer/amd64/linux

The `iso.extract` method detects it's a link and uses the second path to
extract the file. However, when the `file` command is executed in the test
case against the first path, it results in a file not found error because the
link hasn't been created.

[Javier Collado (javier.collado)]

I also see that `iso.extract` only checks for links when outfile is None. This
means that if I try to pass outfile argument, then it won't work the way I'd
like to. That would be that even if the file is a link, its contents is
extracted to the desired location so that subsequent commands can rely on that
the filename exists.

[Javier Collado (javier.collado)]

This isn't causing a problem anymore because the link that was causing the
problem seems to be created the other way around now.

I'm not very happy with the merge proposal I created, so I'm going to mark this
bug as "Won't Fix" since it's unlikely that the build will change again.

Anyway, if the problem happens again, this bug can be reopened and the branch
that was proposed updated to have a good solution for this.

[Javier Collado (javier.collado)]

It turns out that the same problem is back:
https://jenkins.qa.ubuntu.com/job/raring-server-i386-smoke-default/29/console

Looking at the solution I worked on to make it work right.