Description of problem:
When using DVR, fip is unreachable because compute node doesn't have qrouter and fip namespaces created.

There are server logs from controllers and l3 and ovs agent logs from the compute node. They should contain following resources:

(overcloud) [stack@f12-h17-b01-5039ms ~]$ openstack router list --name dvrrouter
+--------------------------------------+-----------+--------+-------+-------------+-------+----------------------------------+
| ID                                   | Name      | Status | State | Distributed | HA    | Project                          |
+--------------------------------------+-----------+--------+-------+-------------+-------+----------------------------------+
| b1622b17-bb7c-41d9-ba21-754874cdee1e | dvrrouter | ACTIVE | UP    | True        | False | 766f7590521c44cb9b5fb71e37346bab |
+--------------------------------------+-----------+--------+-------+-------------+-------+----------------------------------+
(overcloud) [stack@f12-h17-b01-5039ms ~]$ openstack network list --name dvrtest
+--------------------------------------+---------+--------------------------------------+
| ID                                   | Name    | Subnets                              |
+--------------------------------------+---------+--------------------------------------+
| 297c4367-3b59-46a9-9a93-738d13c9ce79 | dvrtest | 05801741-eb1b-48c1-b282-d3f66e8aaa2f |
+--------------------------------------+---------+--------------------------------------+
(overcloud) [stack@f12-h17-b01-5039ms ~]$ openstack subnet list --name dvrtest_subnet
+--------------------------------------+----------------+--------------------------------------+-----------------+
| ID                                   | Name           | Network                              | Subnet          |
+--------------------------------------+----------------+--------------------------------------+-----------------+
| 05801741-eb1b-48c1-b282-d3f66e8aaa2f | dvrtest_subnet | 297c4367-3b59-46a9-9a93-738d13c9ce79 | 192.168.42.0/24 |
+--------------------------------------+----------------+--------------------------------------+-----------------+
(overcloud) [stack@f12-h17-b01-5039ms ~]$ openstack port list --network dvrtest
+--------------------------------------+------+-------------------+------------------------------------------------------------------------------+--------+
| ID                                   | Name | MAC Address       | Fixed IP Addresses                                                           | Status |
+--------------------------------------+------+-------------------+------------------------------------------------------------------------------+--------+
| 78a276ea-f194-4114-8327-73d57d687ba6 |      | fa:16:3e:9c:bf:bb | ip_address='192.168.42.23', subnet_id='05801741-eb1b-48c1-b282-d3f66e8aaa2f' | ACTIVE |
| b244ae83-9aec-453c-ac4b-851c685d8875 |      | fa:16:3e:51:95:64 | ip_address='192.168.42.2', subnet_id='05801741-eb1b-48c1-b282-d3f66e8aaa2f'  | ACTIVE |
| c6377ace-66b0-45f2-a4aa-907682f671dd |      | fa:16:3e:8b:90:16 | ip_address='192.168.42.1', subnet_id='05801741-eb1b-48c1-b282-d3f66e8aaa2f'  | ACTIVE |
| c8f1b0ca-4aab-4440-b680-152f688fbfef |      | fa:16:3e:e7:a4:18 | ip_address='192.168.42.10', subnet_id='05801741-eb1b-48c1-b282-d3f66e8aaa2f' | ACTIVE |
| d42e1089-7c50-4618-a50e-9a59834d783e |      | fa:16:3e:d2:ac:a3 | ip_address='192.168.42.3', subnet_id='05801741-eb1b-48c1-b282-d3f66e8aaa2f'  | ACTIVE |
| df1e3d60-746d-4b97-bdb0-27bdd3c3fc9c |      | fa:16:3e:43:69:20 | ip_address='192.168.42.4', subnet_id='05801741-eb1b-48c1-b282-d3f66e8aaa2f'  | ACTIVE |
+--------------------------------------+------+-------------------+------------------------------------------------------------------------------+--------+
(overcloud) [stack@f12-h17-b01-5039ms ~]$ openstack port list --router dvrrouter
+--------------------------------------+------+-------------------+------------------------------------------------------------------------------+--------+
| ID                                   | Name | MAC Address       | Fixed IP Addresses                                                           | Status |
+--------------------------------------+------+-------------------+------------------------------------------------------------------------------+--------+
| 78a276ea-f194-4114-8327-73d57d687ba6 |      | fa:16:3e:9c:bf:bb | ip_address='192.168.42.23', subnet_id='05801741-eb1b-48c1-b282-d3f66e8aaa2f' | ACTIVE |
| c6377ace-66b0-45f2-a4aa-907682f671dd |      | fa:16:3e:8b:90:16 | ip_address='192.168.42.1', subnet_id='05801741-eb1b-48c1-b282-d3f66e8aaa2f'  | ACTIVE |
| e35b9b1d-35c2-4493-8dab-c7f44d16e3ee |      | fa:16:3e:29:8c:ed | ip_address='172.21.2.27', subnet_id='9ebc48aa-26e0-46af-a65f-27a31676d752'   | ACTIVE |
+--------------------------------------+------+-------------------+------------------------------------------------------------------------------+--------+

On compute node, there are no namespaces
[root@overcloud-compute-2 ~]# ip net
[root@overcloud-compute-2 ~]# 

The flows for br-int and br-tun are also attached. The traffic gets dropped by table 1

[root@overcloud-compute-2 ~]# ovs-ofctl dump-flows br-int in_port=2
 cookie=0xa74d484a786516f8, duration=3689.805s, table=0, n_packets=214, n_bytes=8988, priority=2,in_port="patch-tun",dl_src=fa:16:3f:00:0c:97 actions=resubmit(,1)
 cookie=0xa74d484a786516f8, duration=3689.800s, table=0, n_packets=77, n_bytes=3234, priority=2,in_port="patch-tun",dl_src=fa:16:3f:4b:ed:9e actions=resubmit(,1)
 cookie=0xa74d484a786516f8, duration=3689.796s, table=0, n_packets=63, n_bytes=3078, priority=2,in_port="patch-tun",dl_src=fa:16:3f:6c:66:e1 actions=resubmit(,1)
 cookie=0xa74d484a786516f8, duration=3689.791s, table=0, n_packets=485, n_bytes=20370, priority=2,in_port="patch-tun",dl_src=fa:16:3f:a5:46:32 actions=resubmit(,1)
 cookie=0xa74d484a786516f8, duration=3689.786s, table=0, n_packets=1941, n_bytes=179018, priority=2,in_port="patch-tun",dl_src=fa:16:3f:db:04:b0 actions=resubmit(,1)
 cookie=0xa74d484a786516f8, duration=3689.781s, table=0, n_packets=59, n_bytes=3158, priority=2,in_port="patch-tun",dl_src=fa:16:3f:e5:65:5e actions=resubmit(,1)
[root@overcloud-compute-2 ~]# ovs-ofctl dump-flows br-int table=1
 cookie=0xa74d484a786516f8, duration=3696.303s, table=1, n_packets=2831, n_bytes=217350, priority=1 actions=drop

Version-Release number of selected component (if applicable):
openstack-neutron-13.0.3-0.20190119134915.886782c.el7ost.noarch

How reproducible:
always

Steps to Reproduce:
openstack network create dvrtest
openstack subnet create --network dvrtest dvrtest_subnet --subnet-range 192.168.42.0/24
openstack router create dvrrouter
openstack router set --external-gateway public dvrrouter
openstack router add subnet  dvrrouter dvrtest_subnet
openstack server create --image cirros --flavor m1.tiny --nic net-id=dvrtest --security-group test  --availability-zone nova:overcloud-compute-2.localdomain dvrvm
# the test security group allows ssh and ping
openstack floating ip create public
openstack floating ip set --port c8f1b0ca-4aab-4440-b680-152f688fbfef 172.21.2.38
# c8f1b0ca-4aab-4440-b680-152f688fbfef is the port of the VM
# 172.21.2.38 is the floating ip
ping 172.21.2.38

Actual results:
floating ip is not reachable

Expected results:


Additional info: