We do a ton of host networking checks around the CRI plugin, all mainly
doing the same thing of checking the different quirks on various platforms
(for windows are we a HostProcess pod, for linux is namespace mode the
right thing, darwin doesn't have CNI support etc.) which could all be
bundled up into a small helper that can be re-used.
Signed-off-by: Danny Canter <danny@dcantah.dev>
golang has enabled RFC 6555 Fast Fallback (aka HappyEyeballs)
by default in 1.12.
It means that if a host resolves to both IPv6 and IPv4,
it will try to connect to any of those addresses and use the
working connection.
However, the implementation uses go routines to start both connections in parallel,
and this has limitations when running inside a namespace, so we try to the connections
serially, trying IPv4 first for keeping the same behaviour.
xref https://github.com/golang/go/issues/44922
Signed-off-by: Antonio Ojea <aojea@redhat.com>
