For LXC containers we're using images from LinuxContainers.org, but they or somebody else decided to remove images for armhf architecture, which we use in Turris Omnia a few days ago.
Now we're using minimal root filesystem directly from Alpine developers from their official website, but they're primarily made for chroot or Docker. I created issue on Github and hopefully they bring back Alpine images for armhf at LinuxContainers.org
First I will show you how to install Alpine in LXC containers and then we'll need to do some stuff like setup network manually and install busybox-initscripts and after reboot or each start of LXC containers to have networking connection.
This manual was tested by a community for Alpine version 3.6 a 3.7.
Can be find here https://doc.turris.cz/doc/en/public/lxc_for_beginners
Login to the SSH and install LXC containers how it is advised in official LXC article so it means that first, you need USB flash drive or hard drive, where do you install LXC container and then you need enter the folder, where you have it mounted and do this command:
lxc-create -t download -n nameofyourcontainer
Now you need to attach it with this command
lxc-attach -n nameofyourcontainer
Now you need to setup network manually by this
mount -t proc proc proc/ ifconfig eth0 x.x.x.x netmask y.y.y.y up route add default gw z.z.z.z echo "nameserver 18.104.22.168" > /etc/resolv.conf
Now you need to add initialization scripts
apk update apk add busybox-initscripts
Create configuration file for network
/etc/network/interfaces with content
auto eth0 iface eth0 inet dhcp hostname $(hostname)
Set automatic startup for network
rc-update add networking rc-update add bootmisc boot rc-update add syslog boot
Now you need to reboot it and it's done.