Containers with LXC

2018

Installation

sudo apt install lxc

sudo apt install bridge-utils debootstrap #libvirt-daemon-system libvirt-clients

  • Check the kernel configuration:

lxc-checkconfig

Creating a container

The /vdisk/vmXX/ directory contains the lxc.conf file defining the entire container configuration, the rootfs directory with all the virtual machine data and the run.sh file. allowing the machine to start.

Recovering data from the virtual machine. In our case the distribution is debian stretch version with a 64-bit architecture.

debootstrap --include=lxc --arch=amd64 buster rootfs

Creating /vdisk/vmXX/lxc.conf configuration without network interface

# lxc version 2
lxc.utsname = vm1
lxc.arch = x86_64

# filesystem
lxc.rootfs.path = /vdisk/vmXX/rootfs
lxc.mount.entry=proc /proc proc nodev,noexec,nosuid 0 0
lxc.mount.entry=tmpfs /dev/shm tmpfs  defaults 0 0
lxc.pts=1024

# Environment variable to pass into the conteneur for user root
lxc.environment= PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin
lxc.environment= TERM=xterm

# lxc version 2
name = vm1
architecture = x86_64

# filesystem
lxc.rootfs.path = /mnt/vdisk/rootfs
lxc.mount.entry=proc /proc proc nodev,noexec,nosuid 0 0
lxc.mount.entry=tmpfs /dev/shm tmpfs  defaults 0 0
lxc.tty.max=1024

# Environment variable to pass into the conteneur for user root
lxc.environment= PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin
lxc.environment= TERM=xterm

Add the virtual machine to LXC (/var/lib/lxc)

lxc-create -n vm1 -f /vdisk/vmXX/lxc.conf  -t none

Open a bash in for a virtual machine

lxc-attach -n vm1 -f /mnt/vdisk/lxc.conf

Run a task in the container

lxc-execute -n vm1 -f /vdisk/vmXX/lxc.conf -- /bin/ls

Container network configuration

  • With a bridge

Dans /vdisk/vmXX/lxc.conf

 # networking
 lxc.network.type = veth
 lxc.network.flags = up
 lxc.network.link = br0
 lxc.network.hwaddr = C0:00:00:F0:00:01
 lxc.network.ipv4 = 192.168.42.61/24
 lxc.network.ipv4.gateway = 192.168.42.129
 #lxc.network.ipv6 =

In /etc/network/interfaces, add the bridge br0 to link to the physical interface enp0s3 with a static address.

auto br0
iface br0 inet static
  bridge_ports enp0s3
  bridge_fd 0
  bridge_maxwait 0
  address 192.168.42.60
  netmask 255.255.255.0
  gateway 192.168.42.129

  • Forwarding activation

 echo "1" > /proc/sys/net/ipv4/ip_forward

Installing Apache2 in the container

Open a container terminal, then install apache2.

lxc-attach -n vm1 -f /mnt/vdisk/lxc.conf
apt install apache2

At the host machine level, we can start the container and stop it.

lxc-start -n vm1 -f /mnt/vdisk/lxc.conf -d
lxc-stop -n vm1