ovn-migration: Change network type from vxlan to Geneve

The patch goes to one of ovn-dbs nodes and runs a SQL query to change
all vxlan networks to Geneve. It's done via Python and sqlalchemy in
neutron_api container because mysql client is not installed there. This
approach was chosen to avoid installing more dependencies.

Change-Id: Ic417a115fdc212527866122bc9d3c93ea9599bdf
Signed-off-by: Jakub Libosvar <libosvar@redhat.com>

tools/ovn_migration/tripleo_environment/playbooks/ovn-migration.yml

@@ -33,6 +33,16 @@
   tags:
     - migration
 
+
+# It runs tasks on ovn-dbs nodes
+# 1. Change vxlan network type to Geneve
+- name: Prepare controllers
+  hosts: ovn-dbs
+  roles:
+    - prepare-controllers
+  tags:
+    - migration
+
 #
 # TripleO / Director is executed to deploy ovn using "br-migration" for the
 # dataplane, while br-int is left intact to avoid dataplane disruption.

tools/ovn_migration/tripleo_environment/playbooks/roles/prepare-controllers/defaults/main.yml

@@ -0,0 +1,2 @@
+---
+neutron_conf_path: /var/lib/config-data/puppet-generated/neutron/etc/neutron/neutron.conf

tools/ovn_migration/tripleo_environment/playbooks/roles/prepare-controllers/tasks/main.yml

@@ -0,0 +1,9 @@
+---
+- name: Get DB connection string
+  command: crudini --get {{ neutron_conf_path }} database connection
+  when: ovn_central is defined
+  register: mysql_url
+
+- name: Change vxlan networks to Geneve
+  shell: podman exec -it neutron_api python3 -c $'from sqlalchemy import create_engine\nengine = create_engine("{{ mysql_url.stdout }}")\nwith engine.connect() as conn:\n\tconn.execute("update networksegments set networksegments.network_type=\'geneve\' where networksegments.network_type=\'vxlan\';")'
+  when: ovn_central is defined