When the containers.conf field "NetNS" is set to "Bridge" and the
"RootlessNetworking" field is set to "cni", Podman will now
handle rootless in the same way it does root - all containers
will be joined to a default CNI network, instead of exclusively
using slirp4netns.
If no CNI default network config is present for the user, one
will be auto-generated (this also works for root, but it won't be
nearly as common there since the package should already ship a
config).
I eventually hope to remove the "NetNS=Bridge" bit from
containers.conf, but let's get something in for Brent to work
with.
Signed-off-by: Matthew Heon <mheon@redhat.com>