Container networking relies on NAT to allow container network packets
out to the host's network. This requires a PF firewall to perform the
translation. A simple example is included - to use it:

# cp /usr/local/etc/containers/pf.conf.sample /etc/pf.conf
...
Edit /etc/pf.conf and set v4egress_if, v6egress_if to your network interface(s)s
...
# sysrc pf_enable=YES
# service pf start

The sample PF configuration includes support for port redirections. These are
implemented as redirect rules in anchors nested under cni-rdr.

Support for redirecting connections from the container host to services running
inside a container is included for FreeBSD 13.3 and later. To enable this, first
load the pf kernel module, by adding pf_load="YES" to /boot/loader.conf and
enable PF support for these redirections using sysctl:

# kldload pf
# sysctl net.pf.filter_local=1
# service pf restart

These redirect rules do not currently work if the destination address is
localhost (e.g. 127.0.0.1 or ::1) - always use the hosts IP address when
connecting to a service inside a container using a port redirection. For example
if host port 1234 is redirected to an http service running in a container, you
could connect to it using:

# fetch -o- http://$(hostname):1234