Avoid ovs restart during package upgrade

When installing/upgrading packages (like ovs) a race-condition may occur
when neutron-ovs-agent tries to restore mesh while ovs is being spawning
down. This results in errors in neutron-ovs-agent like:
ovsdb-client: tcp:127.0.0.1:6640: Open_vSwitch database was removed
ovsdbapp.exceptions.TimeoutException: TXN queue is full

In order to prevent that we disable ablity to restart services on
package installation/upgrade, but do that with handler after
neutron-ovs-agent get stopped.

Change-Id: I4bd717c35e030aa1ede21d9a01460037d1ab070c

handlers/main.yml

@@ -70,6 +70,14 @@
     - "Restart neutron services"
     - "venv changed"
 
+- name: Restart openvswitch
+  service:
+    name: "{{ neutron_ovs_service_name }}"
+    state: restarted
+  listen:
+    - "Restart provider services"
+  when: neutron_needs_openvswitch | bool
+
 - name: Symlink neutron config directory
   file:
     # NOTE(cloudnull): The "src" path is relative. This ensures all files remain

tasks/neutron_install.yml

@@ -29,12 +29,16 @@
   package:
     name: "{{ neutron_package_list }}"
     state: "{{ neutron_package_state }}"
+    policy_rc_d: "{{ (neutron_needs_openvswitch | bool and ansible_facts['pkg_mgr'] == 'apt') | ternary(101, omit) }}"
     update_cache: "{{ (ansible_facts['pkg_mgr'] == 'apt') | ternary('yes', omit) }}"
     cache_valid_time: "{{ (ansible_facts['pkg_mgr'] == 'apt') | ternary(cache_timeout, omit) }}"
   register: install_packages
   until: install_packages is success
   retries: 5
   delay: 2
+  notify:
+    - "Restart neutron services"
+    - "Restart provider services"
 
 - name: Remove known problem packages
   package:
@@ -70,7 +74,6 @@
     venv_build_constraints: "{{ _u_c_contents.content.split('\n') | reject('match', '^(ceilometer|neutron)=') | list }}"
     venv_build_distro_package_list: "{{ neutron_devel_distro_packages }}"
     venv_install_destination_path: "{{ neutron_bin | dirname }}"
-    venv_install_distro_package_list: "{{ neutron_package_list }}"
     venv_pip_install_args: "{{ neutron_pip_install_args }}"
     venv_pip_packages: "{{ neutron_venv_packages }}"
     venv_facts_when_changed: