Setting Up LXC Containers on the Host LAN in Ubuntu 22.04

Making my LXC containers accessible on the host machine LAN is something I had successfully done using the old networking interfaces way.

However, Ubuntu 22.04 uses Netplan and I don’t care to fight with the default way anymore by removing netplan etc so it was time to bite the bullet and figure out how to do it with Netplan.

I found this how to on how to change netplan from network manager to networkd, (see the bottom).

The commands in case it goes away:

sudo systemctl enable systemd-resolved.service
sudo systemctl enable systemd-networkd.service
sudo systemctl start systemd-resolved.service
sudo systemctl start systemd-networkd.service
sudo systemctl disable NetworkManager.service
sudo systemctl stop NetworkManager.service

Setting up br0, also from the above tutorial, the current /etc/netplan/01-network-manager-all.yaml:

network:
  version: 2
  renderer: networkd

  ethernets:
    eth0:
      dhcp4: false
      dhcp6: false 

  bridges:
    br0:
      interfaces: [enp7s0]
      addresses: [192.168.68.250/24]
      routes:
      - to: default
        via: 192.168.68.1
        metric: 100
        on-link: true
      mtu: 1500
      nameservers:
        addresses: [1.1.1.1, 8.8.8.8]
      parameters:
        stp: true
        forward-delay: 4
      dhcp4: no
      dhcp6: no

And then sudo netplan apply in order to create the new bridge having the static IP 192.168.68.250, note that enp7s0 is my NIC.

Let’s pretend I have a container called www74, the flow is then to:

1.) Do lxc exec www74 bash or SSH into it if you’ve got that setup.

2.) Run: echo ‘network: {config: disabled}’ > /etc/cloud/cloud.cfg.d/99-disable-network-config.cfg

3.) nano /etc/netplan/50-cloud-init.yaml and replace contents with:

network:
    version: 2
    ethernets:
      eth0:
        dhcp4: false
        dhcp6: false 
        addresses: [192.168.68.221/24]
        routes:
        - to: default
          via: 192.168.68.1
          metric: 100
          on-link: true
        mtu: 1500
        nameservers:
          addresses: [1.1.1.1, 8.8.8.8]

Note that in this case we want www74 to have the static IP 192.168.68.221 on the host’s LAN.

4.) Finally:

lxc stop www74
lxc network attach br0 www74 eth0 eth0
lxc start www74

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This entry was posted on Wednesday, September 13th, 2023 at 3:55 am and is filed under Linux. Comments are currently closed.