IP Block Lists & Docker Networking

fine_sandy_bottom@discuss.tchncs.de to Selfhosted@lemmy.world – 15 points –

Just wondered if any one is using block lists for their docker containers.

IPSum publishes a great list of IPs worth blocking.

The thing is, I know docker networking interacts with iptables in a complex way such that the iptables INPUT chain is ignored.

The docker docs say you can put custom rules in DOCKER-USER chain, but my iptables knowledge isn't great and I think I'm more likely to mess something up than to have any success.

The thing is, I'm sure that this is something loads of other people have encountered, and I'm sure there must be an easier way.

6

Some thing like this

iptables -I DOCKER-USER -m set --match-set ipsum src -j DROP

Should do what you need

Thank you. I was looking at something like this.

I guess I was asking whether there's a package or project which kinda creates this rule and keeps the ipset list updated.

If I create a rule like that, then next time I'm playing around with this I'm not going to be able to figure out what I've done.

I would have a cron that runs a script to pull the list and update IPset, this might not work.

make a file on your docker server with the below in it, set the file to execute chmod +x file.sh

#!/bin/sh
ipset -q flush ipsum
ipset -q create ipsum hash:ip
for ip in $(curl --compressed https://raw.githubusercontent.com/stamparm/ipsum/master/ipsum.txt 2>/dev/null | grep -v "#" | grep -v -E "\s[1-2]$" | cut -f 1); do ipset add ipsum $ip; done
iptables -D INPUT -m set --match-set ipsum src -j DROP 2>/dev/null
iptables -I INPUT -m set --match-set ipsum src -j DROP

Then add a cron file in /etc/cron.d that runs the script every 24 hours

10 3 * * * root /root/file.sh