Docker CE breaks KVM bridged networking

Rocky Linux Help & Support
1

Hi,

I’m running Rocky Linux 8 on my main workstation. For testing purposes I’m using KVM/libvirt since it performs much better than VirtualBox.

I just installed Docker CE from the official Docker repository and found out that this breaks KVM networking. I’m using a br0 bridge for KVM, and when I start Docker, all KVM hosts become unreachable.

After googling “docker breaks kvm bridge” I found out that I’m not the only one affected by this problem. And before trying out the various suggested solutions using iptables scripts, I thought I’d like to ask here before. I’m curious if there’s a clean fix for this under Rocky Linux 8.

Thanks & cheers from the rainy South of France.

2

Quickest and easiest - run Docker in a VM on the machine instead of attempting it to run alongside KVM. Or, instead of docker, use podman (unless that breaks KVM too) as this is available by default and practically the same (if not better in my opinion) than docker.

3

This sounds like a good solution. There’s only one problem with it. I’m teaching a course about Docker at the local university, and I need the real thing (e. g. Docker CE) on my workstation.

If it was only for my own purposes, I’d gladly run Podman.

4

Yep, totally understand. The VM route is probably the easiest than trying to get docker to play nicely with KVM.