As a failsave the migration code can create a backup of
the controllers to use in case that the migration fails
and leaves the environment on a unusable state.
The revert plan has two stages:
1- Backup stage: included on the current ovn-migration.yml.
Can be configured using the env variable CREATE_BACKUP
(True by default). This stage will run the new ansible
role, recovery-backup.
It will store the backup on `/ctl_plane_backup` on the host
where the BACKUP_MIGRATION_IP belongs to (can be modified by
modifing the env var).
In order to restore the controllers, boot them using the iso created
by ReaR (stored in /ctl_plane_backup) and perform `automatic recover`
2- Revert stage: this stage has its own ansible playbook (revert.yml)
This playbook will clean the environment from all the OVN ressources
that could had been created (breaking the data plane connectivity)
to leave the environment in a stage where an overcloud deploy with
the OVS templates can be run.
Note: If the user creates new resources after running the backup stage
and then performs the recovery of the controllers, those resources will
be lost.
Conflicts:
tools/ovn_migration/tripleo_environment/ovn_migration.sh
Change-Id: I7093f6a5f282b06fb2267cf2c88c533c1eae685d
(cherry picked from commit 7003817b69)
c35aed1b30