Add support for customising Neutron physical network names

Previously Kolla Ansible hard-coded Neutron physical networks starting
at physnet1 up to physnetN, matching the number of interfaces in
neutron_external_interface and bridges in neutron_bridge_name.

Sometimes we may want to customise the physical network names used. This
may be to allow for not all hosts having access to all physical
networks, or to use more descriptive names.

For example, in an environment with a separate physical network for
Ironic provisioning, controllers might have access to two physical
networks, while compute nodes have access to one.

This change adds a neutron_physical_networks variable, making it
possible to customise the Neutron physical network names used for the
OVS, OVN, Linux bridge and OVS DPDK plugins. The default behaviour is
unchanged.

Change-Id: Ib5b8ea727014964919c6b3bd2352bac4a4ac1787

ansible/group_vars/all.yml

@@ -1080,6 +1080,7 @@ designate_notifications_topic_name: "notifications_designate"
 #######################
 neutron_bgp_router_id: "1.1.1.1"
 neutron_bridge_name: "{{ 'br-dvs' if neutron_plugin_agent == 'vmware_dvs' else 'br_dpdk' if enable_ovs_dpdk | bool else 'br-ex' }}"
+neutron_physical_networks: "{% for bridge in neutron_bridge_name.split(',') %}physnet{{ loop.index }}{% if not loop.last %},{% endif %}{% endfor %}"
 # Comma-separated type of enabled ml2 type drivers
 neutron_type_drivers: "flat,vlan,vxlan{% if neutron_plugin_agent == 'ovn' %},geneve{% endif %}"
 # Comma-separated types of tenant networks (should be listed in 'neutron_type_drivers')

ansible/roles/neutron/templates/linuxbridge_agent.ini.j2

@@ -5,7 +5,8 @@ extensions = {{ neutron_agent_extensions|map(attribute='name')|join(',') }}
 
 [linux_bridge]
 {% if inventory_hostname in groups["network"] or (inventory_hostname in groups["compute"] and computes_need_external_bridge | bool ) %}
-physical_interface_mappings = {% for interface in neutron_external_interface.split(',') %}physnet{{ loop.index0 + 1 }}:{{ interface }}{% if not loop.last %},{% endif %}{% endfor %}
+{# Format: physnet1:br1,physnet2:br2 #}
+physical_interface_mappings = {{ neutron_physical_networks.split(',') | zip(neutron_external_interface.split(',')) | map('join', ':') | join(',') }}
 {% endif %}
 
 [securitygroup]

ansible/roles/neutron/templates/ml2_conf.ini.j2

@@ -15,7 +15,7 @@ extension_drivers = {{ neutron_extension_drivers | map(attribute='name') | join(
 
 [ml2_type_vlan]
 {% if enable_ironic | bool %}
-network_vlan_ranges = physnet1
+network_vlan_ranges = {{ neutron_physical_networks }}
 {% else %}
 network_vlan_ranges =
 {% endif %}
@@ -24,7 +24,7 @@ network_vlan_ranges =
 {% if enable_ironic | bool %}
 flat_networks = *
 {% else %}
-flat_networks = {% for interface in neutron_external_interface.split(',') %}physnet{{ loop.index0 + 1 }}{% if not loop.last %},{% endif %}{% endfor %}
+flat_networks = {{ neutron_physical_networks }}
 {% endif %}
 
 [ml2_type_vxlan]

ansible/roles/neutron/templates/openvswitch_agent.ini.j2

@@ -15,7 +15,8 @@ firewall_driver = neutron.agent.linux.iptables_firewall.OVSHybridIptablesFirewal
 
 [ovs]
 {% if inventory_hostname in groups["network"] or (inventory_hostname in groups["compute"] and computes_need_external_bridge | bool ) %}
-bridge_mappings = {% for bridge in neutron_bridge_name.split(',') %}physnet{{ loop.index0 + 1 }}:{{ bridge }}{% if not loop.last %},{% endif %}{% endfor %}
+{# Format: physnet1:br1,physnet2:br2 #}
+bridge_mappings = {{ neutron_physical_networks.split(',') | zip(neutron_bridge_name.split(',')) | map('join', ':') | join(',') }}
 {% endif %}
 datapath_type = {{ ovs_datapath }}
 ovsdb_connection = tcp:127.0.0.1:{{ ovsdb_port }}

ansible/roles/ovn-controller/tasks/setup-ovs.yml

@@ -12,8 +12,10 @@
 
 - name: Configure OVN in OVSDB
   vars:
-    ovn_mappings: "{% for bridge in neutron_bridge_name.split(',') %}physnet{{ loop.index0 + 1 }}:{{ bridge }}{% if not loop.last %},{% endif %}{% endfor %}"
+    # Format: physnet1:br1,physnet2:br2
-    ovn_macs: "{% for bridge in neutron_bridge_name.split(',') %}physnet{{ loop.index0 + 1 }}:{{ ovn_base_mac | random_mac(seed=inventory_hostname + bridge) }}{% if not loop.last %},{% endif %}{% endfor %}"
+    ovn_mappings: "{{ neutron_physical_networks.split(',') | zip(neutron_bridge_name.split(',')) | map('join', ':') | join(',') }}"
+    # Format: physnet1:00:11:22:33:44:55,physnet2:00:11:22:33:44:56
+    ovn_macs: "{% for physnet, bridge in neutron_physical_networks.split(',') | zip(neutron_bridge_name.split(',')) %}{{ physnet }}:{{ ovn_base_mac | random_mac(seed=inventory_hostname + bridge) }}{% if not loop.last %},{% endif %}{% endfor %}"
     ovn_cms_opts: "{{ 'enable-chassis-as-gw' if inventory_hostname in groups['ovn-controller-network'] else '' }}{{ ',availability-zones=' + neutron_ovn_availability_zones | join(',') if inventory_hostname in groups['ovn-controller-network'] and neutron_ovn_availability_zones }}"
   become: true
   kolla_toolbox:

ansible/roles/ovs-dpdk/defaults/main.yml

@@ -37,8 +37,10 @@ ovsdpdk_services:
 ####################
 # OVS
 ####################
-ovs_bridge_mappings: "{% for bridge in neutron_bridge_name.split(',') %}physnet{{ loop.index0 + 1 }}:{{ bridge }}{% if not loop.last %},{% endif %}{% endfor %}"
+# Format: physnet1:br1,physnet2:br2
-ovs_port_mappings: "{% for bridge in neutron_bridge_name.split(',') %} {{ neutron_external_interface.split(',')[loop.index0] }}:{{ bridge }}{% if not loop.last %},{% endif %}{% endfor %}"
+ovs_bridge_mappings: "{{ neutron_physical_networks.split(',') | zip(neutron_bridge_name.split(',')) | map('join', ':') | join(',') }}"
+# Format: eth1:br1,eth2:br2
+ovs_port_mappings: "{{ neutron_external_interface.split(',') | zip(neutron_bridge_name.split(',')) | map('join', ':') | join(',') }}"
 tunnel_interface_network: "{{ hostvars[inventory_hostname].ansible_facts[dpdk_tunnel_interface]['ipv4']['network'] }}/{{ hostvars[inventory_hostname].ansible_facts[dpdk_tunnel_interface]['ipv4']['netmask'] }}"
 tunnel_interface_cidr: "{{ dpdk_tunnel_interface_address }}/{{ tunnel_interface_network | ipaddr('prefix') }}"
 ovs_cidr_mappings: "{% if neutron_bridge_name.split(',') | length != 1 %} {neutron_bridge_name.split(',')[0]}:{{ tunnel_interface_cidr }} {% else %} {{ neutron_bridge_name }}:{{ tunnel_interface_cidr }} {% endif %}"

doc/source/reference/networking/neutron.rst

@@ -20,13 +20,20 @@ Neutron external interface is used for communication with the external world,
 for example provider networks, routers and floating IPs.
 For setting up the neutron external interface modify
 ``/etc/kolla/globals.yml`` setting ``neutron_external_interface`` to the
-desired interface name. This interface is used by hosts in the ``network``
+desired interface name or comma-separated list of interface names. Its default
-group. It is also used by hosts in the ``compute`` group if
+value is ``eth1``. These external interfaces are used by hosts in the
+``network`` group.  They are also used by hosts in the ``compute`` group if
 ``enable_neutron_provider_networks`` is set or DVR is enabled.
 
-The interface is plugged into a bridge (Open vSwitch or Linux Bridge, depending
+The external interfaces are each plugged into a bridge (Open vSwitch or Linux
-on the driver) defined by ``neutron_bridge_name``, which defaults to ``br-ex``.
+Bridge, depending on the driver) defined by ``neutron_bridge_name``, which
-The default Neutron physical network is ``physnet1``.
+defaults to ``br-ex``. When there are multiple external interfaces,
+``neutron_bridge_name`` should be a comma-separated list of the same length.
+
+The default Neutron physical network is ``physnet1``, or ``physnet1`` to
+``physnetN`` when there are multiple external network interfaces. This may be
+changed by setting ``neutron_physical_networks`` to a comma-separated list of
+networks of the same length.
 
 Example: single interface
 -------------------------
@@ -54,6 +61,30 @@ These two lists are "zipped" together, such that ``eth1`` is plugged into the
 Ansible maps these interfaces to Neutron physical networks ``physnet1`` and
 ``physnet2`` respectively.
 
+Example: custom physical networks
+---------------------------------
+
+Sometimes we may want to customise the physical network names used. This may be
+to allow for not all hosts having access to all physical networks, or to use
+more descriptive names.
+
+For example, in an environment with a separate physical network for Ironic
+provisioning, controllers might have access to two physical networks:
+
+.. code-block:: yaml
+
+   neutron_external_interface: "eth1,eth2"
+   neutron_bridge_name: "br-ex1,br-ex2"
+   neutron_physical_network: "physnet1,physnet2"
+
+While compute nodes have access only to ``physnet2``.
+
+.. code-block:: yaml
+
+   neutron_external_interface: "eth1"
+   neutron_bridge_name: "br-ex1"
+   neutron_physical_network: "physnet2"
+
 Example: shared interface
 -------------------------
 

releasenotes/notes/neutron-physical-networks-5b908bed9809c3b4.yaml

@@ -0,0 +1,6 @@
+---
+features:
+  - |
+    Adds a ``neutron_physical_networks`` variable for customising Neutron
+    physical network names. The default behaviour of using ``physnet1`` to
+    ``physnetN`` is unchanged.