ovn migration: Turn validations off by default

The validation is intended mostly for tests and don't make much sense
when running the migration in production because likely there are
already running workloads. This patch changes the default to False so
migration validation must be explicitly asked for.

Change-Id: I5470f61a5e0b55bf682526208c3f57dc0ca6ffd5
Signed-off-by: Jakub Libosvar <[email protected]>
(cherry picked from commit 0baf884)

Author: cubeek

doc/source/ovn/migration.rst

@@ -136,7 +136,7 @@ Perform the following steps in the undercloud
    * VALIDATE_MIGRATION - Create migration resources to validate the
      migration. The migration script, before starting the migration, boot a
      server and validates that the server is reachable after the migration.
-     Default: True.
+     Default: False
 
    * SERVER_USER_NAME - User name to use for logging into the migration
      instances.

releasenotes/notes/change-migration-validation-b030b02c5e1acd3d.yaml

@@ -0,0 +1,12 @@
+---
+other:
+  - |
+    The OVN migration performs validation by default. This validation means an
+    instance is spawned and is tested by simple ping after the migration is
+    finished. Also it tries to create new workload post migration. This is
+    useful for very simple scenarios when migration is tested but is not
+    really useful in production since likely the production envrionments
+    already have running workloads. It makes more sense to require the
+    validation explicitly rather than implicitly run it as the migration
+    is mostly intended for production. The VALIDATE_MIGRATION now defaults to
+    False and needs to be changed to True if validation upon request.

tools/ovn_migration/tripleo_environment/ovn_migration.sh

@@ -39,7 +39,7 @@ LANG=C
 : ${IMAGE_NAME:=cirros}
 : ${FLAVOR_NAME:=ovn-migration}
 : ${SERVER_USER_NAME:=cirros}
-: ${VALIDATE_MIGRATION:=True}
+: ${VALIDATE_MIGRATION:=False}
 : ${DHCP_RENEWAL_TIME:=30}
 : ${CREATE_BACKUP:=True}
 : ${BACKUP_MIGRATION_IP:=192.168.24.1} # TODO: Document this new var