Add test boot_into_snapshot_after_upgrade

[Zaoliang]

add boot_into_snapshot after upgrade from DVD installation
see https://progress.opensuse.org/issues/12964
verifications:
http://10.162.23.47/tests/8183 (BOOT_INTO_SNAPSHOT_AFTER_UPGRADE)
http://10.162.23.47/tests/8185 (SLES boot_into_snapshot)
http://10.162.23.47/tests/8184 (TW boot_into_snapshot)

[Zaoliang]

http://10.162.23.47/tests/8022#step/boot_into_snapshot/8 for example.

And I can't see the need of it:
assert_script_run('touch /etc/NOWRITE;test ! -f /etc/NOWRITE');

[SergioAtSUSE]

http://10.162.23.47/tests/8022#step/boot_into_snapshot/8 for example.

That failed job is caused by a wrong use of module boot_into_snapshot, because the SUT was booted into the normal writable snapshot: http://10.162.23.47/tests/8022#step/boot_to_desktop/3

Please see: #10919 (comment)

[SergioAtSUSE]

And I can't see the need of it:
assert_script_run('touch /etc/NOWRITE;test ! -f /etc/NOWRITE');

It is necessary to check if the SUT booted into a read-only snapshot.

[SergioAtSUSE]

Let me propose the following.

1. Rename boot_into_snapshot to rollback_from_ro_snapshot.
2. Schedule rollback_from_ro_snapshot as the last module from test suite upgrade_Leap_15.1_gnome.
3. Create a test module called boot_into_snapshot which should be executed instead of grub_test before rollback_from_ro_snapshot, which should take care of waiting for grub and booting into the RO snapshot.
4. Verify changes on following scenarios
   • https://openqa.opensuse.org/tests/latest?arch=x86_64&distri=opensuse&flavor=DVD&machine=64bit&test=boot_to_snapshot&version=Tumbleweed
   • https://openqa.opensuse.org/tests/latest?arch=x86_64&distri=opensuse&flavor=DVD&machine=64bit&test=upgrade_Leap_15.1_gnome&version=Tumbleweed#

[SergioAtSUSE]

In ticket, AC1 states: boot_into_snapshot is scheduled at the end of upgrade_Leap_15.1_gnome scenario (Leap->Tumbleweed) for the last Leap version.

There is no verification run for test suite upgrade_Leap_15.1_gnome.
And the creation of test suite boot_into_snapshot_after_upgrade is invalid.

[SergioAtSUSE]

Annoyingly, the test module boot_into_snapshot doesn't boot into a snapshot. It is only scheduled in test suite boot_to_snapshot and directly after grub_test, which boots into a RO snapshot if setting BOOT_TO_SNAPSHOT is present (See https://github.com/os-autoinst/os-autoinst-distri-opensuse/blob/master/tests/installation/grub_test.pm#L80)
Then, boot_into_snapshot expects the SUT to be already booted into a RO snapshot and performs checks and the rollback (in my opinion, the test module boot_into_snapshot should be renamed to rollback_from_ro_snapshot to properly describe what it does).

Because boot_into_snapshot expects the system booted into a RO snapshot, the check assert_script_run('touch /etc/NOWRITE;test ! -f /etc/NOWRITE'); is mandatory.
If the check fails, it means that the SUT is on a writable snapshot, and that could mean that there is a product bug or a test bug. In this case, the failure is a test bug, since the verification run http://10.162.23.47/tests/8183, shows the module boot_into_snapshot scheduled after:

• grub_test (which is booting into default writable snapshot)
• first_boot
• opensuse_welcome

So, the changes on file tests/installation/boot_into_snapshot.pm are wrong.

[Zaoliang]

re-worked according to ticket. Close this PR and please follow:

#11142