Staggered upgrade procedure for OVS clouds

doc/source/operations/upgrading-openstack.rst

@@ -1063,6 +1063,12 @@ This will block the upgrade, but may be overridden by setting
 ``etc/kayobe/kolla/globals.yml`` or
 ``etc/kayobe/environments/<env>/kolla/globals.yml``.
 
+Depending on the networking architecture of your cloud, the steps used
+to upgrade the containerised services will differ.
+
+OVN
+^^^
+
 To upgrade the containerised control plane services:
 
 .. code-block:: console
@@ -1076,6 +1082,80 @@ scope of the upgrade:
 
    kayobe overcloud service upgrade --tags config --kolla-tags keystone
 
+OVS
+^^^
+
+You should first stop the Octavia health manager to prevent alerts during
+the service upgrade.
+
+.. code-block:: console
+
+   kayobe overcloud host command run --command "docker stop octavia_health_manager" --limit controllers --become
+
+For dedicated network nodes, upgrade the control plane services:
+
+.. code-block:: console
+
+   kayobe overcloud service upgrade --kolla-limit controllers
+
+For converged network nodes, you should specify the service limit to only
+upgrade the Neutron API service.
+
+.. code-block:: console
+
+   kayobe overcloud service upgrade --kolla-limit controllers -ke neutron_service_limit=neutron-server
+
+To ensure L3 reliability during the upgrade, we will need to sequentially drain
+and upgrade each network node by first disabling agents and then running a targeted upgrade.
+the network nodes of all agents, and upgrade the nodes sequentially.
+
+Kolla credentials will need to be activated before running the neutron-namespace-drain
+role.
+
+.. code-block:: console
+
+   source $KOLLA_CONFIG_PATH/public-openrc.sh
+
+You should substitute <network0> with the first network node to be drained, To set
+the node for maintenance and begin draining the agents:
+
+.. code-block:: console
+
+   kayobe playbook run $KAYOBE_CONFIG_PATH/ansible/neutron-l3-drain.yml -e neutron_namespace_drain_host=<network0> -e maintenance=true -e neutron_namespace_drain_dhcp_agents=true
+
+You can monitor the L3/DHCP agents being drained from the node by running:
+
+.. code-block:: console
+
+   ssh -t <network0> watch ip netns ls
+
+Once all agents have been drained, you can upgrade the containerised services
+on the network node. For dedicated network nodes run:
+
+.. code-block:: console
+
+   kayobe overcloud service upgrade --kolla-limit <network0>
+
+Converged network nodes will require specifying the the service limit for the Neutron
+agents.
+
+.. code-block:: console
+
+   kayobe overcloud service upgrade --kolla-limit <network0> -ke neutron_service_limit='neutron-openvswitch-agent,neutron-dhcp-agent,neutron-l3-agent,neutron-metadata-agent,ironic-neutron-agent'
+
+Following the service upgrade, the agents can be restored on the node by disabling maintenance:
+
+.. code-block:: console
+
+   kayobe playbook run $KAYOBE_CONFIG_PATH/ansible/neutron-l3-drain.yml -e neutron_namespace_drain_host=<network0> -e maintenance=false -e neutron_namespace_drain_dhcp_agents=true
+
+The above steps should be repeated for the remaining network nodes, once all network nodes have been upgraded
+the remaining containerised services can be upgraded:
+
+.. code-block:: console
+
+   kayobe overcloud service upgrade --kolla-tags common,nova,prometheus,openvswitch,neutron --skip-prechecks  -kl controllers,compute --limit controllers,compute
+
 Updating the Octavia Amphora Image
 ----------------------------------
 

etc/kayobe/ansible/neutron-l3-drain.yml

@@ -0,0 +1,25 @@
+---
+- name: Drain neutron of l3 agents and dhcp agents
+  hosts: localhost
+  gather_facts: true
+  tags:
+    - neutron-l3-drain
+  vars:
+    maintenance: false
+    neutron_namespace_drain_ctrl1: false
+    neutron_namespace_drain_ctrl2: false
+    neutron_namespace_drain_ctrl3: false
+  tasks:
+    - name: Drain hosts
+      ansible.builtin.import_role:
+        name: stackhpc.openstack_ops.neutron_namespace_drain
+        tasks_from: main.yml
+      when: neutron_namespace_drain_ctrl1 | bool or neutron_namespace_drain_ctrl2 | bool or neutron_namespace_drain_ctrl3 | bool or neutron_namespace_drain_host is defined
+
+    - name: Print info
+      ansible.builtin.debug:
+        msg:
+          - "{{ neutron_namespace_drain_host }} is read for maintenance"
+          - "rerun this play book with -e maintenance=false to re-add"
+          - "routers"
+      when: maintenance | bool

etc/kayobe/ansible/requirements.yml

@@ -12,6 +12,9 @@ collections:
     version: 2.5.1
   - name: stackhpc.kayobe_workflows
     version: 1.1.0
+  - name: https://github.com/stackhpc/ansible-collection-openstack-ops
+    type: git
+    version: feature/neutron-namespace-drain
 roles:
   - src: stackhpc.vxlan
   - name: ansible-lockdown.ubuntu22_cis