Description of problem:
When navigating through https://bugzilla.redhat.com/show_bug.cgi?id=1725596, I've seen this behaviour in my scripts:

[root@wsfd-netdev19 ~]# ovs-vsctl add-port br0 gre0 -- set interface gre0 type=ip6gre options:key=100 options:remote_ip=2001::2
ovs-vsctl: Error detected while setting up 'gre0': could not add network device gre0 to ofproto (Address family not supported by protocol).  See ovs-vswitchd log for details.
ovs-vsctl: The default log directory is "/var/log/openvswitch".
[root@wsfd-netdev19 ~]# echo $?
0

Well, it's is correct because the port actually was added:
[root@wsfd-netdev19 ~]# ovs-vsctl show
e904851c-9eed-4041-8dd6-af304d379ca0
    Bridge ovs-sriov
        Port "eth0"
            Interface "eth0"
        Port "bond9"
            Interface "bond9"
        Port ovs-sriov
            Interface ovs-sriov
                type: internal
    Bridge "br0"
        Port "br0"
            Interface "br0"
                type: internal
        Port "ns2-veth-ab"
            Interface "ns2-veth-ab"
        Port "gre0"
            Interface "gre0"
                type: "ip6gre"
                options: {key="100", remote_ip="2001::2"}
                error: "could not add network device gre0 to ofproto (Address family not supported by protocol)"
    ovs_version: "2.11.0"


This happens with unknown interfaces as well:

[root@wsfd-netdev19 ~]# ovs-vsctl add-port br0 foobar
ovs-vsctl: Error detected while setting up 'foobar': could not open network device foobar (No such device).  See ovs-vswitchd log for details.
ovs-vsctl: The default log directory is "/var/log/openvswitch".
[root@wsfd-netdev19 ~]# ovs-vsctl show
e904851c-9eed-4041-8dd6-af304d379ca0
    Bridge ovs-sriov
        Port "eth0"
            Interface "eth0"
        Port "bond9"
            Interface "bond9"
        Port ovs-sriov
            Interface ovs-sriov
                type: internal
    Bridge "br0"
        Port "br0"
            Interface "br0"
                type: internal
        Port foobar
            Interface foobar
                error: "could not open network device foobar (No such device)"


But this is also bad because the script cannot easily detect such error condition, and so would OSP and others when adding this tunnel interface.

Is there a way to make this operation more strict, and error out on such conditions? Is it actually wanted?
Or to query (without parsing ovs-vsctl output) if a port is at least minimally functional?


Version-Release number of selected component (if applicable):
openvswitch2.11-2.11.0-14.el7fdp.x86_64