The iptables args list needs to include all fields as they are eventually spit
out by iptables-save. This is because some systems do not support the
'iptables -C' arg, and so fall back on parsing iptables-save output. If this
does not match, it will not pass the check. For example: adding the /32 on
the destination IP arg is not strictly required, but causes this list to not
match the final iptables-save output. This is fragile and I hope one day we
can stop supporting such old iptables versions.
This makes iptables an injectable dependency. The test for this started off
simple, but got a bit out of hand. It's starting to become a mocking
framework.