Nova: add live_migration_interface option

This option is useful in environments where the live-migration traffic
can impact the network plane significantly.
A separate network for live-migration traffic can then use this config
option and avoids the impact on the management network.

Change-Id: Id16c95e77730e5b244cf5bc69beb0e549c979701

nova/templates/bin/_nova-compute-init.sh.tpl

@@ -23,3 +23,17 @@ mkdir -p /var/lib/nova/instances
 
 # Set Ownership of nova dirs to the nova user
 chown ${NOVA_USER_UID} /var/lib/nova /var/lib/nova/instances
+
+migration_interface="{{- .Values.conf.libvirt.live_migration_interface -}}"
+if [[ -n $migration_interface ]]; then
+    # determine ip dynamically based on interface provided
+    migration_address=$(ip r | grep $migration_interface | grep -v default | awk '{print $9}')
+fi
+
+touch /tmp/pod-shared/nova-libvirt.conf
+if [[ -n $migration_address ]]; then
+cat <<EOF>/tmp/pod-shared/nova-libvirt.conf
+[libvirt]
+live_migration_inbound_addr = $migration_address
+EOF
+fi

nova/templates/bin/_nova-compute.sh.tpl

@@ -20,4 +20,5 @@ set -ex
 
 exec nova-compute \
       --config-file /etc/nova/nova.conf \
-      --config-file /tmp/pod-shared/nova-console.conf
+      --config-file /tmp/pod-shared/nova-console.conf \
+      --config-file /tmp/pod-shared/nova-libvirt.conf

nova/templates/daemonset-compute.yaml

@@ -67,6 +67,8 @@ spec:
               readOnly: true
             - name: varlibnova
               mountPath: /var/lib/nova
+            - name: pod-shared
+              mountPath: /tmp/pod-shared
         {{- if .Values.conf.ceph.enabled }}
         {{- if empty .Values.conf.ceph.cinder.keyring }}
         - name: ceph-admin-keyring-placement

nova/values.yaml

@@ -1019,6 +1019,10 @@ conf:
     DEFAULT:
       scheduler_host_manager: ironic_host_manager
       compute_driver: ironic.IronicDriver
+  libvirt:
+    # Get the IP address to be used as the target for live migration traffic using interface name.
+    # If this option is set to None, the hostname of the migration target compute node will be used.
+    live_migration_interface:
   nova:
     DEFAULT:
       default_ephemeral_format: ext4