Add config to set neutron mtu in undercloud/overcloud

In some environments we are setting the mtu at the
operating system level without setting the mtu in neutron.
This can lead to errors and failed tempest tests.

Closes-Bug: #1714660
Depends-On: I16f8f49b8e4ea35407ab2f2794d5dce8f2c03019
Change-Id: Iedd4cfbb0e1c9471cb1ae53b8b6acc266273463f

config/environments/rdocloud-ci.yml

@@ -29,3 +29,12 @@ ipa_image_url: http://images.rdoproject.org/{{ release }}/rdo_trunk/{{ dlrn_hash
 docker_registry_host: trunk.registry.rdoproject.org
 docker_registry_namespace: "{{ release }}"
 
+mtu: 1350
+mtu_interface:
+    - eth0
+    - eth1
+    - "{% if network_isolation|default(true)|bool %}eth2{% endif %}"
+
+undercloud_local_mtu: "{{ mtu }}"
+overcloud_neutron_global_physnet_mtu: "{{ mtu }}"
+

config/environments/rdocloud.yml

@@ -29,3 +29,12 @@ overcloud_image_url: http://images.rdoproject.org/{{ release }}/rdo_trunk/{{ dlr
 ipa_image_url: http://images.rdoproject.org/{{ release }}/rdo_trunk/{{ dlrn_hash|default(dlrn_hash_tag) }}/ironic-python-agent.tar
 docker_registry_host: trunk.registry.rdoproject.org
 docker_registry_namespace: "{{ release }}"
+
+mtu: 1350
+mtu_interface:
+    - eth0
+    - eth1
+    - "{% if network_isolation|default(true)|bool %}eth2{% endif %}"
+
+undercloud_local_mtu: "{{ mtu }}"
+overcloud_neutron_global_physnet_mtu: "{{ mtu }}"

config/general_config/ovb-ha-multiple-nics.yml

@@ -56,11 +56,8 @@ hostname_correction: true
 
 # adjust mtus
 step_adjust_mtu: true
-mtu: 1350
-mtu_interface:
-    - eth0
-    - eth1
-    - eth2
+undercloud_local_mtu: "{{ mtu }}"
+overcloud_neutron_global_physnet_mtu: "{{ mtu }}"
 
 # set up external interface
 external_interface: eth2

config/general_config/ovb-minimal-pacemaker-public-bond.yml

@@ -57,11 +57,8 @@ hostname_correction: true
 
 # adjust mtus
 step_adjust_mtu: true
-mtu: 1350
-mtu_interface:
-    - eth0
-    - eth1
-    - eth2
+undercloud_local_mtu: "{{ mtu }}"
+overcloud_neutron_global_physnet_mtu: "{{ mtu }}"
 
 # set up external interface
 external_interface: eth2

roles/overcloud-deploy/tasks/create-scripts.yml

@@ -48,3 +48,10 @@
   template:
     src: "resource-registry-nic-configs.yaml.j2"
     dest: "{{ working_dir }}/resource-registry-nic-configs.yaml"
+
+- name: Create the overcloud network parameters yaml
+  when:
+    - overcloud_neutron_global_physnet_mtu is defined
+  template:
+    src: "overcloud_network_params.yaml.j2"
+    dest: "{{ working_dir }}/overcloud_network_params.yaml"

roles/overcloud-deploy/tasks/pre-deploy.yml

@@ -227,3 +227,11 @@
     swap_args: >-
       -e {{ overcloud_templates_path }}/environments/enable-swap-partition.yaml
   when: enable_swap|bool and swap_type == 'partition'
+
+- name: set network_args for mtu settings
+  set_fact:
+    network_args: >-
+      {{ network_args }}
+      -e {{ working_dir }}/overcloud_network_params.yaml
+  when:
+    - overcloud_neutron_global_physnet_mtu is defined

roles/overcloud-deploy/templates/overcloud_network_params.yaml.j2

@@ -0,0 +1,4 @@
+# Defines overcloud network parameters based on parameters given.
+
+parameter_defaults:
+  NeutronGlobalPhysnetMtu: {{ overcloud_neutron_global_physnet_mtu }}

roles/undercloud-deploy/templates/undercloud.conf.j2

@@ -44,6 +44,12 @@ local_ip = {{undercloud_local_ip|default(
 network_gateway = {{undercloud_network_gateway|default(
     undercloud_network_cidr|nthhost(1))}}
 
+# MTU, set neutron on the undercloud to match mtu of the nics
+# (string value)
+{% if undercloud_local_mtu is defined %}
+local_mtu = {{ undercloud_local_mtu }}
+{% endif %}
+
 {% if release in ['mitaka', 'newton'] %}
 # Virtual IP address to use for the public endpoints of Undercloud
 # services.  Only used if undercloud_service_certficate is set.