Ubuntu 12.04 64bit desktop : how to install/use Linux Container ( LXC ) part 1

I’m newbie to lxc.
Here’s an explanation of how to install lxc , make containers.

host server info , which is running within KVM.

# uname –ri 3.2.0-34-generic x86_64 # lsb_release -a No LSB modules are available. Distributor ID: Ubuntu Description:    Ubuntu 12.04.1 LTS Release:        12.04 Codename:       precise

[ install lxc ]

install lxc package via apt-get

# apt-get install lxc –y

# lxc-version lxc version: 0.7.5

check what kind of kernel namespace your kernel on the host supports.

root@ubuntu1204:~# lxc-checkconfig Kernel config /proc/config.gz not found, looking in other places... Found kernel config file /boot/config-3.2.0-34-generic --- Namespaces --- Namespaces: enabled Utsname namespace: enabled Ipc namespace: enabled Pid namespace: enabled User namespace: enabled Network namespace: enabled Multiple /dev/pts instances: enabled --- Control groups --- Cgroup: enabled Cgroup clone_children flag: enabled Cgroup device: enabled Cgroup sched: enabled Cgroup cpu account: enabled Cgroup memory controller: enabled Cgroup cpuset: enabled --- Misc --- Veth pair device: enabled Macvlan: enabled Vlan: enabled File capabilities: enabled

sample template files for containers.

# ls /usr/lib/lxc/templates/ lxc-busybox  lxc-fedora    lxc-sshd    lxc-ubuntu-cloud lxc-debian   lxc-opensuse  lxc-ubuntu

sample configuration files for network configuration.

# ls /usr/share/doc/lxc/examples/ lxc-complex.conf      lxc-macvlan.conf   lxc-phys.conf  lxc-vlan.conf lxc-empty-netns.conf  lxc-no-netns.conf  lxc-veth.conf

network configuration file.

# cat /etc/lxc/lxc.conf lxc.network.type=veth lxc.network.link=lxcbr0 lxc.network.flags=up

# brctl show bridge name     bridge id               STP enabled     interfaces lxcbr0          8000.000000000000       no

build ubuntu 12.10 ( quantal ) container using lxc-ubuntu template

# lxc-create -t ubuntu -n quantal-01 -- -r quantal No config file specified, using the default config debootstrap is /usr/sbin/debootstrap <snip> ## # The default user is 'ubuntu' with password 'ubuntu'! # Use the 'sudo' command to run tasks as root in the container. ## 'ubuntu' template installed 'quantal-01' created root@ubuntu1204:~#

containers are installed under /var/lib/lxc/ by default.

# ls /var/lib/lxc/quantal-01/* /var/lib/lxc/quantal-01/config  /var/lib/lxc/quantal-01/rootfs.hold /var/lib/lxc/quantal-01/fstab /var/lib/lxc/quantal-01/rootfs: bin   dev  home  lib64  mnt  proc  run   selinux  sys  usr boot  etc  lib   media  opt  root  sbin  srv      tmp  var

list containers

# lxc-list –all RUNNING FROZEN STOPPED  quantal-01

get info about quantal-01 container.

# lxc-info -n quantal-01 state:   STOPPED lxc-info: 'quantal-01' is not running pid:        -1

start the container.
root : ubuntu , credentials : ubuntu

# lxc-start -n quantal-01 process 10: arguments to dbus_server_disconnect() were incorrect, assertion "old_refcount > 0" failed in file ../../dbus/dbus-server.c line 786. This is normally a bug in some application using the D-Bus library. process 10: arguments to dbus_server_unref() were incorrect, assertion "old_refcount > 0" failed in file ../../dbus/dbus-server.c line 749. This is normally a bug in some application using the D-Bus library. Ubuntu 12.10 quantal-01 console quantal-01 login: ubuntu Password: Welcome to Ubuntu 12.10 (GNU/Linux 3.2.0-34-generic x86_64) * Documentation:  https://help.ubuntu.com/ The programs included with the Ubuntu system are free software; the exact distribution terms for each program are described in the individual files in /usr/share/doc/*/copyright. Ubuntu comes with ABSOLUTELY NO WARRANTY, to the extent permitted by applicable law. ubuntu@quantal-01:~$ root@quantal-01:~# lsb_release -a No LSB modules are available. Distributor ID: Ubuntu Description:    Ubuntu 12.10 Release:        12.10 Codename:       quantal root@quantal-01:~# uname -ri 3.2.0-34-generic x86_64

on the host

# lxc-ps --name quantal-01 CONTAINER    PID TTY          TIME CMD quantal-01 18227 ?        00:00:00 init quantal-01 18359 ?        00:00:00 upstart-udev-br quantal-01 18383 ?        00:00:00 udevd quantal-01 18391 ?        00:00:00 rsyslogd quantal-01 18393 ?        00:00:00 upstart-socket- quantal-01 18431 ?        00:00:00 dhclient quantal-01 18453 ?        00:00:00 sshd quantal-01 18487 pts/5    00:00:00 getty quantal-01 18490 pts/3    00:00:00 getty quantal-01 18492 pts/4    00:00:00 getty quantal-01 18499 ?        00:00:00 cron quantal-01 18517 pts/7    00:00:00 login quantal-01 18521 pts/2    00:00:00 getty quantal-01 18537 pts/7    00:00:00 bash quantal-01 18552 pts/7    00:00:00 sudo quantal-01 18553 pts/7    00:00:00 su quantal-01 18554 pts/7    00:00:00 bash

on the host

# lxc-info lxc-info: missing container name, use --name option root@ubuntu1204:~# lxc-info --name quantal-01 state:   RUNNING pid:     18227

connect to the container via lxc-console

root@ubuntu1204:~# lxc-console --name quantal-01 Type <Ctrl+a q> to exit the console Ubuntu 12.10 quantal-01 tty1 quantal-01 login: ubuntu Password: Last login: Tue Dec  4 07:13:06 UTC 2012 on lxc/console Welcome to Ubuntu 12.10 (GNU/Linux 3.2.0-34-generic x86_64) * Documentation:  https://help.ubuntu.com/ ubuntu@quantal-01:~$  <- Crtl a + q to quit console root@ubuntu1204:~#

shutdown the container from the host


on the host

root@ubuntu1204:~# lxc-shutdown --name quantal-01

make a clone container from the quantal-01 container.


on the host

root@ubuntu1204:~# lxc-clone -o quantal-01 -n quantal-02 Tweaking configuration Copying rootfs... Updating rootfs... 'quantal-02' created

root@ubuntu1204:~# ls /var/lib/lxc/ quantal-01  quantal-02

start quantal-02 without tty access. ( -d )

root@ubuntu1204:~# lxc-start -n quantal-02 -d -c /var/log/lxc-console.log

-d, --daemon              Run the container as a daemon. As the container has no more tty,              if  an  error occurs nothing will be displayed, the log file can              be used to check the error.     -c, --console console_file              Specify a file to output the container console. If the option is              not specified the output will go the terminal except if  the  -d              is specified.

root@ubuntu1204:~# lxc-list --all RUNNING  quantal-02 FROZEN STOPPED  quantal-01

connect to the quantal-02

root@ubuntu1204:~# lxc-console -n quantal-02 Type <Ctrl+a q> to exit the console Ubuntu 12.10 quantal-02 tty1 quantal-02 login: ubuntu Password: Last login: Tue Dec  4 07:13:21 UTC 2012 on lxc/tty1 Welcome to Ubuntu 12.10 (GNU/Linux 3.2.0-34-generic x86_64) * Documentation:  https://help.ubuntu.com/ ubuntu@quantal-02:~$ root@ubuntu1204:~#

remove a container from file system entirely

root@ubuntu1204:~# lxc-list RUNNING FROZEN STOPPED  quantal-01  quantal-02 root@ubuntu1204:~# lxc-destroy -n quantal-02 root@ubuntu1204:~# root@ubuntu1204:~# lxc-list RUNNING FROZEN STOPPED  quantal-01 root@ubuntu1204:~# root@ubuntu1204:~# ls /var/lib/lxc/ quantal-01