Tabla de Contenidos

LXC Debian Wheezy at DigitalOcean

Installation

apt-get install -y lxc libvirt-bin

Mount the cgroup: 

vim /etc/fstab
cgroup  /sys/fs/cgroup  cgroup  defaults  0   0
mount /sys/fs/cgroup

Make available live-debconfig package to taken by Debian Wheezy containers: 

echo "deb http://ftp.de.debian.org/debian unstable main contrib non-free" > /etc/apt/sources.list.d/live-debconfig.list  
apt-get update
cd /usr/share/lxc/packages
apt-get download live-debconfig
rm /etc/apt/sources.list.d/live-debconfig.list 
apt-get update

Mark default Network to autostart: 

virsh net-autostart default

and start it: 

virsh net-start default

Check installation

Run these commands and read output: 

mount
cgroup on /sys/fs/cgroup type cgroup (rw,relatime,perf_event,blkio,net_cls,freezer,devices,cpuacct,cpu,cpuset)
virsh net-info default

ip addr show virbr0
lxc-checkconfig

A Container

Create

Command: 

lxc-create -n nombrecontainer -t debian
  1. Ingresa a una interfaz que pide datos varios (enter… enter…)
  2. demora bastante, ya que descarga todo debian utilizando debootstrap
  3. deja instalado un debian SUPER básico

Network at container

Add to /var/lib/lxc/nombrecontainer/config 

## Network
lxc.network.type = veth
lxc.network.flags = up

# Network host side
lxc.network.link = virbr0

# MUST BE UNIQUE FOR EACH CONTAINER
lxc.network.veth.pair = veth0
lxc.network.hwaddr = 00:FF:AA:00:00:01

# Network container side
lxc.network.name = eth0
lxc.network.ipv4 = 0.0.0.0/24

Start container

lxc-start -n nombrecontainer -d

Attach to console

lxc-console -n nombrecontainer

Type <Ctrl+a q> to exit the console

Access services into Container

Configure static IP

At /var/lib/libvirt/network/default.xml configure fix IP address to each container's MAC address: 

<dhcp>
  <range start="192.168.122.201" end="192.168.122.254" />
  <host mac="00:FF:AA:00:00:01" name="foo.example.com" ip="192.168.122.101" />
  <host mac="00:FF:AA:00:00:02" name="bar.example.com" ip="192.168.122.102" />
</dhcp>

los pasos siguientes hace que los contenedores pierdan la red 

virsh net-destroy default
virsh net-start default

Port forwarding

All services are access by just one IP address then same service into different container requires different public port

ssh into each container

iptables -t nat -A PREROUTING -p tcp --dport 1022 -j DNAT --to 192.168.122.101:22

http into just one container

iptables -t nat -A PREROUTING -p tcp --dport 80 -j DNAT --to 192.168.122.102