Can't run commands within dhcp namespaces(created by neutron): " from overcloud controller(Containerized Services)

[yatin]

Description:
============
Not able to execute commands within network namespaces(ip netns exec <qdhcp-namespace> ip a) on overcloud controller(Containerized)

Steps to reproduce:
===================
1) Install Containerized Overcloud using tripleo-quickstart, I used following overcloud deploy command:-
Release used: master-tripleo-ci

openstack overcloud deploy \
    --templates /usr/share/openstack-tripleo-heat-templates \
    --libvirt-type qemu --control-flavor oooq_control --compute-flavor oooq_compute --ceph-storage-flavor oooq_ceph --block-storage-flavor oooq_blockstorage --swift-storage-flavor oooq_objectstorage --timeout 90 -e /home/stack/cloud-names.yaml -e /usr/share/openstack-tripleo-heat-templates/environments/network-isolation.yaml -e /usr/share/openstack-tripleo-heat-templates/environments/net-single-nic-with-vlans.yaml -e /home/stack/network-environment.yaml -e /usr/share/openstack-tripleo-heat-templates/environments/low-memory-usage.yaml -e /home/stack/enable-tls.yaml -e /usr/share/openstack-tripleo-heat-templates/environments/tls-endpoints-public-ip.yaml -e /home/stack/inject-trust-anchor.yaml -e /home/stack/cloud-names.yaml -e /usr/share/openstack-tripleo-heat-templates/environments/docker.yaml --validation-warnings-fatal --ntp-server pool.ntp.org

2) Login to undercloud(stack user) and Create flavor, image, network and then a VM on overcloud
source overcloudrc
curl -O http://download.cirros-cloud.net/0.3.5/cirros-0.3.5-x86_64-disk.img
openstack image create --disk-format qcow2 --container-format bare --public --file ./cirros-0.3.5-x86_64-disk.img cirros
openstack flavor create --public m1.extra_tiny --id auto --ram 256 --disk 0 --vcpus 1 --rxtx-factor 1
openstack security group rule create default --protocol tcp --dst-port 22:22 --remote-ip 0.0.0.0/0
openstack security group rule create --protocol icmp default
openstack network create net1
openstack subnet create subnet1 --network net1 --subnet-range 192.0.2.0/24
netid=$(openstack network show net1 -f value -c id)
nova boot --nic net-id=$netid --image cirros --flavor m1.extra_tiny testvm
# Wait for some time for VM to be in ACTIVE state

# Login to overcloud controller node to run commands in neutron namespaces
# Login as root
# List network namespaces
ip netns
# run command within namespace found, namespace would be named qdhcp-<network-id>
ip netns exec <qdhcp namespace> ip a
ip netns exec <qdhcp namespace> ping <vm ip>

Expected result:
===============
Both commands should return some output

Actual result:
==============
Both command gives below Error:-
[root@overcloud-controller-0 ~]# ip netns exec qdhcp-5c73dc75-bf29-4a0a-bd9c-b37f5c593229 ip a
RTNETLINK answers: Invalid argument
setting the network namespace "qdhcp-5c73dc75-bf29-4a0a-bd9c-b37f5c593229" failed: Invalid argument

# Some more info:-

I am able to run above commands with "docker exec -it <neutron dhcp container> sudo ip netns exec <qdhcp namespace> ip a
Also check file permission on controller and in docker container: ls -l /var/run/netns/<qdchp namespace>
On controller something below:-
----------. 1 root root 0 May 31 10:01 qdhcp-5c73dc75-bf29-4a0a-bd9c-b37f5c593229
On Container something below:
-r--r--r--. 1 root root 0 May 31 10:01 qdhcp-5c73dc75-bf29-4a0a-bd9c-b37f5c593229

NOTE: sudo command can't be run in container, i somehow updated sudoers file within container and executed netns commands
devname=$(sudo docker inspect -f '{{ .GraphDriver.Data.DeviceName }}' neutron_dhcp)
sudo dmsetup info $devname

# Get minor number for the device
minornum=$(sudo dmsetup info $devname |grep Major|cut -d"," -f 3)
Hence the docker device for container is dm-<minor number>

# Mount the device and you can access container file system.

[Brent Eagles (beagles)]

From the description, this problem should be resolved by https://review.openstack.org/#/c/542858/

[yatin (yatinkarel)]

Yes, on latest deployment i checked, it's working. Thanks.

[root@overcloud-controller-foo-0 ~]# ip netns exec qdhcp-c0738e41-5800-4ced-b213-4735169b26e5 ip a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN qlen 1
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host
       valid_lft forever preferred_lft forever
51: tapbba0e044-b2: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1450 qdisc noqueue state UNKNOWN qlen 1000
    link/ether fa:16:3e:6e:0c:a4 brd ff:ff:ff:ff:ff:ff
    inet 192.0.2.2/24 brd 192.0.2.255 scope global tapbba0e044-b2
       valid_lft forever preferred_lft forever
    inet6 fe80::f816:3eff:fe6e:ca4/64 scope link
       valid_lft forever preferred_lft forever