Upgrades, rollback for bootstrap brakes slaves bootstrapping

[Evgeniy L]

1. install 5.0 master node
2. run 5.0.1/5.1 upgrade, make it fail (add exception raising in post bootstrap upgarde section)
3. wait until rollback is done
4. try to reboot slave

Actual result:
Node bootstrapping fails

Expected result:
Node booted with bootstrap image

It happens because of symlink magic in cobbler container

[root@c3afdaa2107d nailgun]# ls -l /var/www/nailgun/
total 0
lrwxrwxrwx 1 root root 15 Jun 4 11:51 bootstrap -> /repo/bootstrap
lrwxrwxrwx 1 root root 12 Jun 4 11:51 centos -> /repo/centos
lrwxrwxrwx 1 root root 12 Jun 4 11:51 docker -> /repo/docker
lrwxrwxrwx 1 root root 5 Jul 24 12:44 dump -> /dump
lrwxrwxrwx 1 root root 22 Jun 4 11:51 puppet-slave.tgz -> /repo/puppet-slave.tgz
lrwxrwxrwx 1 root root 12 Jun 4 11:51 ubuntu -> /repo/ubuntu
[root@c3afdaa2107d nailgun]# ls -l /repo/
total 1236
drwxr-xr-x 2 root root 38 Jun 4 11:31 5.0_bootstrap
drwxr-xr-x 4 root root 32 Jul 23 13:55 5.1
drwxr-xr-x 2 root root 38 Jun 4 13:25 5.1_bootstrap
lrwxrwxrwx 1 root root 31 Jul 24 12:46 bootstrap -> /var/www/nailgun/5.0_bootstrap/
drwxr-xr-x. 3 root root 20 Jun 4 11:31 centos
drwxr-xr-x. 4 root root 49 Jun 4 11:32 docker
drwxr-xr-x 2 root root 6 Jun 4 11:51 dump
-rwxr-xr-x. 1 root root 1265298 Jun 4 11:31 puppet-slave.tgz
drwxr-xr-x. 3 root root 20 Jun 4 11:31 ubuntu

VERSION:
  feature_groups:
    - mirantis
  production: "docker"
  release: "5.1"
  api: "1.0"
  build_number: "70"
  build_id: "2014-07-23_15-32-11"
  astute_sha: "fd9b8e3b6f59b2727b1b037054f10e0dd7bd37f1"
  fuellib_sha: "fb0e84c954a33c912584bf35054b60914d2a2360"
  ostf_sha: "c1b60d4bcee7cd26823079a86e99f3f65414498e"
  nailgun_sha: "06b9becc1e6831351aac693290ac619c92e56e99"
  fuelmain_sha: "7b03801a70506b1c9efc2aec8a6203bc916a5b89"

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/109285

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: stable/5.0
Review: https://review.openstack.org/109293

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/109285
Committed: https://git.openstack.org/cgit/stackforge/fuel-web/commit/?id=a74fa60388d658aff04aedbc5d7ba7d091713c56
Submitter: Jenkins
Branch: master

commit a74fa60388d658aff04aedbc5d7ba7d091713c56
Author: Evgeniy L <email address hidden>
Date: Thu Jul 24 17:03:28 2014 +0400

    Upgrades, fix rollback for bootstrap engine

    * changed rollback strategy for bootstrap
      upgrade engine, in previous strategy we
      made symlink from previous version of
      bootstrap to /var/www/nailgun/bootstrap
      it doesn't work because in 5.0 version
      cobbler container mounts /var/www/nailgun
      directory as /repo, as result symlinks
      which we make on the host system are
      broken inside of container.

      Instead of symlink command we rename
      previous version to /var/www/nailgun/bootstrap

    * use lexists instead of exists because
      exists returns False on broken symlinks

    * fixed docker engine rollback, there
      was wrong definition of previous version
      of fuel.

    Change-Id: Id0b50835410e005fde76f421981b4616211ddcbf
    Closes-bug: #1348166

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/109293
Committed: https://git.openstack.org/cgit/stackforge/fuel-web/commit/?id=3f19a97e4f250c49742655ef94edd6e33cc9845a
Submitter: Jenkins
Branch: stable/5.0

commit 3f19a97e4f250c49742655ef94edd6e33cc9845a
Author: Evgeniy L <email address hidden>
Date: Thu Jul 24 17:03:28 2014 +0400

    Upgrades, fix rollback for bootstrap engine

    * changed rollback strategy for bootstrap
      upgrade engine, in previous strategy we
      made symlink from previous version of
      bootstrap to /var/www/nailgun/bootstrap
      it doesn't work because in 5.0 version
      cobbler container mounts /var/www/nailgun
      directory as /repo, as result symlinks
      which we make on the host system are
      broken inside of container.

      Instead of symlink command we rename
      previous version to /var/www/nailgun/bootstrap

    * use lexists instead of exists because
      exists returns False on broken symlinks

    * fixed docker engine rollback, there
      was wrong definition of previous version
      of fuel

    Change-Id: Id0b50835410e005fde76f421981b4616211ddcbf
    Closes-bug: #1348166

[Andrey Sledzinskiy (asledzinskiy)]

verified on fuel-5.1-upgrade-9-2014-09-17_04-49-39.tar.lrz