Comment 16 for bug 1831935

Summary:

We had three distinct issues:

1) MTU setting on the DPDK interfaces
This is resolved in master for neutron-openvswitch and the fix can be seen at [0].

2) An upstream neutron bug where the checksum for metadata traffic is not getting filled [1]
that bug will be tracked separately in LP Bug#1832021

3) The neutron-openvswitch charm was not setting force_metadata = True and was not installing haproxy which are requirements for ns-metdata-proxy which proxies metdata requests from the netns to the nova-api-metadata service.
This is being resolved in [2] and will be the focus of this bug.

[0] https://github.com/juju/charm-helpers/pull/333
[1] https://bugs.launchpad.net/neutron/+bug/1832021
[2] https://review.opendev.org/#/c/664001/

Once [2] lands, the neutron-openvswitch will be fully ready at master. It resolves the first and third problems and will NOT require enabling DVR.

Until [1] is resolved upstream, the workaround setting the checksum fill inside the qdhcp ip netns will remain necessary:

iptables -t mangle -A OUTPUT -o ns-+ -p tcp --sport 80 -j CHECKSUM --checksum-fill