# Nspawn Containers [Arch Linux Wiki for Nspawn Containers](https://wiki.archlinux.org/index.php/Systemd-nspawn) ### Create a FileSystem ```bash cd /var/lib/machines # create a directory mkdir # use pacstrap to create a file system pacstrap -i -c -d base --ignore linux ``` ### First boot and create root password ```bash systemd-nspawn -b -D passwd poweroff # if you want to nat the container add *-n* flag systemd-nspawn -b -D -n # and to bind mount the package cache systemd-nspawn -b -D -n --bind=/var/cache/pacman/pkg ``` ### Networking On Arch, assuming you have systemd-networkd and systemd-resolved set up correctly, networking from the host end of things should just work. However on Linode it does not. What does work on Linode is to create a bridge interface. Two files for br0 will get the job done. ```text # /etc/systemd/network/50-br0.netdev [NetDev] Name=br0 Kind=bridge ``` ```text # /etc/systemd/network/50-br0.netdev [Match] Name=br0 [Network] Address=10.0.55.1/24 DHCPServer=yes IPMasquerade=yes ``` Notice how the configuration file tells systemd-networkd to offer DHCP service and to perform masquerade. You can modify the `systemd-nspawn` command to use the bridge interface. Every container attached to this bridge will be on the same subnet and able to talk to each other. ```bash # first restart systemd-networkd to bring up the new bridge interface systemctl restart systemd-networkd # and add --network-bridge=br0 to systemd-nspawn command systemd-nspawn -b -D --network-bridge=br0 --bind=/var/cache/pacman/pkg ``` ### Automatically Starting the Container There are two ways to automate starting the container. You can override `systemd-nspawn@.service` or create an *nspawn* file. First enable machines.target ```bash # to override the systemd-nspawn@.service file cp /lib/systemd/system/systemd-nspawn@.service /etc/systemd/system/systemd-nspawn@.service ``` Edit `/etc/systemd/system/systemd-nspawn@.service` to add the `systemd-nspawn` options you want to the `ExecStart` command. Or create `/etc/systemd/nspawn/.nspawn` ```text # /etc/systemd/nspawn/.nspawn Bind=/var/cache/pacman/pkg [Network] Bridge=br0 ``` ```bash # in either case systemctl start/enable systemd-nspawn@ # to get a shell machinectl shell # and then to get an environment bash ``` ### Initial Configuration Inside The Container ```bash # set time zone if you don't want UTC timedatectl set-timezone # enable ntp, networktime timedatectl set-ntp 1 ``` [If you want to change the locale](https://wiki.archlinux.org/index.php/locale)