Use a single Neutron port for bmc

The original single bmc change configured the bmc instance with
two Neutron ports.  This was done mostly to avoid some extra
manual network configuration in the bmc instance, but it resulted
in duplicate routes to the private network.  Recently it has come
to my attention that Ironic is having intermittent problems
talking to the bmc instance, which may be caused by this duplicate
route.  I had similar problems with the initial single bmc change
because it added N routes to the bmc when N baremetal instances
were created.  Reducing the duplicate routes probably mitigated
the problem, but didn't eliminate it.

This change switches to a single Neutron port for the bmc and does
the necessary configuration via os-net-config so the default route
and the Neutron assigned address will continue to work.  It also
removes the note in the documentation about needing to allow
multiple ports on a single network.

README.rst

@@ -63,10 +63,6 @@ Configuring the Host Cloud
    happen with the baremetal instances booted from an empty image it speeds
    things up a bit.
 
-#. ``/etc/nova/nova.conf`` needs ``allow_duplicate_networks=true`` in the
-   ``[neutron]`` section so that the BMC instance can have multiple nics on the
-   same network.
-
 #. Restart ``nova-compute`` and ``neutron-openvswitch-agent`` to apply the
    changes above.
 

bin/install_openstackbmc.sh

@@ -12,14 +12,25 @@ $openstackbmc_script
 EOF
 chmod +x /usr/local/bin/openstackbmc
 
+export OS_USERNAME=$os_user
+export OS_TENANT_NAME=$os_tenant
+export OS_PASSWORD=$os_password
+export OS_AUTH_URL=$os_auth_url
+private_subnet=$(neutron net-show -f value -c subnets $private_net)
+default_gw=$(neutron subnet-show $private_subnet -f value -c gateway_ip)
+prefix_len=$(neutron subnet-show -f value -c cidr $private_subnet | awk -F / '{print $2}')
+
 mkdir /etc/os-net-config
 echo "network_config:" > /etc/os-net-config/config.yaml
 echo "  -" >> /etc/os-net-config/config.yaml
 echo "    type: interface" >> /etc/os-net-config/config.yaml
-echo "    name: eth1" >> /etc/os-net-config/config.yaml
+echo "    name: eth0" >> /etc/os-net-config/config.yaml
 echo "    use_dhcp: false" >> /etc/os-net-config/config.yaml
-echo "    routes: []" >> /etc/os-net-config/config.yaml
+echo "    routes:" >> /etc/os-net-config/config.yaml
+echo "      - default: true" >> /etc/os-net-config/config.yaml
+echo "        next_hop: $default_gw" >> /etc/os-net-config/config.yaml
 echo "    addresses:" >> /etc/os-net-config/config.yaml
+echo "    - ip_netmask: $bmc_utility/$prefix_len" >> /etc/os-net-config/config.yaml
 
 cat <<EOF >/usr/lib/systemd/system/config-bmc-ips.service
 [Unit]
@@ -38,14 +49,6 @@ StandardError=inherit
 WantedBy=multi-user.target
 EOF
 
-export OS_USERNAME=$os_user
-export OS_TENANT_NAME=$os_tenant
-export OS_PASSWORD=$os_password
-export OS_AUTH_URL=$os_auth_url
-
-private_subnet=$(neutron net-show -f value -c subnets $private_net)
-prefix_len=$(neutron subnet-show -f value -c cidr $private_subnet | awk -F / '{print $2}')
-
 for i in $(seq 1 $bm_node_count)
 do
     bm_port="$bm_prefix_$(($i-1))"

templates/virtual-baremetal.yaml

@@ -124,6 +124,16 @@ resources:
         port_range_min: 623
         port_range_max: 623
 
+  bmc_port:
+    type: OS::Neutron::Port
+    properties:
+      name:
+        list_join:
+        - '_'
+        - - 'utility'
+          - {get_param: bmc_prefix}
+      network: {get_param: private_net}
+
   bmc_server:
     type: OS::Nova::Server
     properties:
@@ -131,8 +141,7 @@ resources:
       image: {get_param: bmc_image}
       key_name: {get_param: key_name}
       networks:
-        - network: {get_param: private_net}
-        - network: {get_param: private_net}
+        - port: {get_resource: bmc_port}
       name: {get_param: bmc_prefix}
       user_data_format: RAW
       user_data:
@@ -144,6 +153,7 @@ resources:
             $os_auth_url: {get_param: os_auth_url}
             $bm_node_count: {get_param: node_count}
             $bmc_prefix: {get_param: bmc_prefix}
+            $bmc_utility: {get_attr: [bmc_port, fixed_ips, 0, ip_address]}
             $bm_prefix: {get_param: baremetal_prefix}
             $private_net: {get_param: private_net}
             $openstackbmc_script: {get_file: ../bin/openstackbmc}