Fix iptables comments ports format

[zaharidichev]

The fact that the comment was containing angle brackets caused the ip tables command to fail when used with netns in turn causing the linkerd cni plugin to not work properly. This fixes that problem.

This fails with 2020/01/17 14:24:06 < Bad argument 4191]/1579271046'`

Command: 
./linkerd-cni --incoming-proxy-port "4143" --outgoing-proxy-port "4140" --proxy-uid "2102" --inbound-ports-to-ignore 4190,4191 --outbound-ports-to-ignore "443" --netns /proc/5850/ns/net
Resulting iptables cmd:
nsenter --net=/proc/5850/ns/net iptables -t nat -A PROXY_INIT_REDIRECT -p tcp --match multiport --dports 4190,4191 -j RETURN -m comment --comment proxy-init/ignore-port-[4190 4191]/1579271046

This does not:

Command: 
./linkerd2-proxy-init-2 --incoming-proxy-port "4143" --outgoing-proxy-port "4140" --proxy-uid "2102" --inbound-ports-to-ignore 4190,4191 --outbound-ports-to-ignore "443"
Resulting iptables cmd:
iptables -t nat -A PROXY_INIT_REDIRECT -p tcp --match multiport --dports 4190,4191 -j RETURN -m comment --comment proxy-init/ignore-port-[4190 4191]/1579271046

Now they both work fine

Signed-off-by: Zahari Dichev [email protected]

[adleong]

Just so I understand, the comment would now look like

--comment proxy-init/ignore-port-4190,4191/1579271046

right?

[zaharidichev]

@adleong after the fix, yes