I recently configured a multi-node Devstack DVR setup and thought it might be useful to share my experience.

I use three VMs: 192.168.0.1/2/3. Each VM has one NIC with internet access. I normally run Devstack Neutron VMs with only one NIC – If the instances you create inside this environment require internet access, just connect the NIC to br-ex and move the IP addressing information to be-ex. I designate one VM as an ‘all-in-one’ (API servers, compute, and network), the second VM as a compute, and the third as a network node. This allows me to test DVR east-west routing (This is why I have two computes) as well as default SNAT behavior (Requires a dedicated network node / A l3 agent in ‘dvr-snat’ mode). I dislike Devstack flags/macros and prefer to configure the services myself with [post-config] sections. This soothes my control-freak nature and allows me to assert that I understand how the configuration should end up looking like.

All in one local.conf:

[[local|localrc]]
DEST=/opt/openstack
DATA_DIR=$DEST/data
LOGFILE=$DATA_DIR/logs/stack.log
SCREEN_LOGDIR=$DATA_DIR/logs
VERBOSE=False
MYSQL_PASSWORD=1
RABBIT_PASSWORD=1
SERVICE_TOKEN=1
SERVICE_PASSWORD=1
ADMIN_PASSWORD=1

disable_service n-net
enable_service neutron
enable_service q-svc
enable_service q-meta
enable_service q-agt
enable_service q-dhcp
enable_service q-l3

# TODO: Set this host's IP
HOST_IP=192.168.0.1

[[post-config|$NEUTRON_CONF]]
[DEFAULT]
router_distributed=True

[[post-config|/$Q_PLUGIN_CONF_FILE]]
[ml2]
type_drivers=flat,vlan,vxlan
tenant_network_types=vxlan
mechanism_drivers=openvswitch,l2population

[ml2_type_vxlan]
vni_ranges=1000:1999

[ovs]
local_ip=$HOST_IP

[agent]
tunnel_types=vxlan
l2_population=True
enable_distributed_routing=True

[[post-config|$Q_L3_CONF_FILE]]
[DEFAULT]
agent_mode=dvr
router_delete_namespaces=True

[[post-config|$Q_DHCP_CONF_FILE]]
[DEFAULT]
dhcp_delete_namespaces=True

Compute local.conf:

[[local|localrc]]
DEST=/opt/openstack
DATA_DIR=$DEST/data
LOGFILE=$DATA_DIR/logs/stack.log
SCREEN_LOGDIR=$DATA_DIR/logs
VERBOSE=False
MYSQL_PASSWORD=1
RABBIT_PASSWORD=1
SERVICE_TOKEN=1
SERVICE_PASSWORD=1
ADMIN_PASSWORD=1

ENABLED_SERVICES=n-cpu,neutron,n-novnc,q-agt,q-l3,q-meta

# TODO: Set this host's IP
HOST_IP=192.168.0.2

# TODO: Set the controller's IP
SERVICE_HOST=192.168.0.1
MYSQL_HOST=$SERVICE_HOST
RABBIT_HOST=$SERVICE_HOST
Q_HOST=$SERVICE_HOST
GLANCE_HOSTPORT=$SERVICE_HOST:9292

VNCSERVER_PROXYCLIENT_ADDRESS=$HOST_IP
VNCSERVER_LISTEN=0.0.0.0

[[post-config|/$Q_PLUGIN_CONF_FILE]]
[ovs]
local_ip=$HOST_IP

[agent]
tunnel_types=vxlan
l2_population=True
enable_distributed_routing=True

[[post-config|$Q_L3_CONF_FILE]]
[DEFAULT]
agent_mode=dvr
router_delete_namespaces=True

Network node local.conf:

[[local|localrc]]
DEST=/opt/openstack
DATA_DIR=$DEST/data
LOGFILE=$DATA_DIR/logs/stack.log
SCREEN_LOGDIR=$DATA_DIR/logs
VERBOSE=False
MYSQL_PASSWORD=1
RABBIT_PASSWORD=1
SERVICE_TOKEN=1
SERVICE_PASSWORD=1
ADMIN_PASSWORD=1

ENABLED_SERVICES=neutron,q-agt,q-l3,q-meta

# TODO: Set this host's IP
HOST_IP=192.168.0.3

# TODO: Set the controller's IP
SERVICE_HOST=192.168.0.1
MYSQL_HOST=$SERVICE_HOST
RABBIT_HOST=$SERVICE_HOST
GLANCE_HOSTPORT=$SERVICE_HOST:9292

[[post-config|/$Q_PLUGIN_CONF_FILE]]
[ovs]
local_ip=$HOST_IP

[agent]
tunnel_types=vxlan
l2_population=True
enable_distributed_routing=True

[[post-config|$Q_L3_CONF_FILE]]
[DEFAULT]
agent_mode=dvr_snat
router_delete_namespaces=True