Description
Here are the two types of networking
# usermode
-netdev user,id=net0,hostfwd=tcp::10022-:22,
-device e1000-82545em,netdev=net0,id=net0,mac=52:54:00:09:49:17
# bridged
-netdev tap,id=net0,ifname=tap0,script=no,downscript=no
-device vmxnet3,netdev=net0,id=net0,mac=52:54:00:AB:F8:B7
user mode
The image has the same IP as your Docker IP ip n to see neighbors
QEMU cannot be reached unless you add ports in the QEMU args during "docker run"
Can't expose Docker ports on a running container (AFAIK), you have to start a new image and move the installation around.
You also have to edit the Launch.sh or add in arguments
bridged mode
The image will run on the container's own internal network, like 10.0.2.15 or something or 192.168.122.11x
After that, you can ssh OR docker exec into the Docker and then ssh into the QEMU image.
which is better?
Realistically, they both appear exactly the same.
Bridge mode would let people forward all connections to the bridge IP.
# usermode
# you have to add
docker run ... -p 50922:10022 -e EXTRA='-netdev user,hostfwd=tcp::10022-:22'
# bridge-mode
docker run ... -p 50922:10022 -ip p.ubl.ic.ip
If anyone wants to test it out:
sudo tee -a /etc/sysctl.conf <<< 'net.ipv4.ip_forward=1'
sudo sysctl -p
sudo pacman -S iptables-nft
sudo systemctl enable --now libvirtd.service
sudo systemctl enable --now virtlogd.service
sudo ip tuntap add dev tap0 mode tap
sudo ip link set tap0 up promisc on
sudo virsh net-autostart default
sudo virsh net-start default
sudo ip link set dev virbr0 up
sudo ip link set dev tap0 master virbr0
# use the networking from above in the QEMU args
The actual bug is ebtalbes + dnsmasq doesn't work virsh networking.
You can test it out:
sudo pacman -S libvirtd
virsh net-info --domain default
# works
Bugged:
sudo pacman -S ebtables dnsmasq
virsh net-info --domain default
# fails
Fix:
sudo pacman -S iptables-nft
virsh net-info --domain default
# works
It's a strange bug, I though related to polkit, however, I found it incompatible with ebtables.
Possibly just with Arch, that the default network doesn't get installed.
Easy fix: replace iptables and ebtables with iptables-nft. If not, virsh hangs, sudo virsh hangs.
On the other hand, QEMU and Docker networking is really, really easy to debug. If bridged network is added, you'd have to start the bridge every time, I also think you need --net host