Documentation and guides

Libvirt On Cubieboard

Bringing up the board

  1. Download and unpack the image for your board.

    For the cubieboard2

    For the cubietruck

  2. Copy to the SDcard, e.g.

    dd if=cubie.img of=/dev/mmcblk0

  3. Boot the device. It should get an IP address by DHCP.

  4. The device announces a .local name using mDNS, so you should be able to ssh to $BOARD.local

    ssh mirage@cubieboard2.local.
  5. To change hostname of the cubieboard:

    edit /etc/hosts

    127.0.1.1       newname

    edit /etc/hostname

    newname
  6. To change the cubieboard to get a static ip address:

    edit /etc/network/interfaces and update with:

    auto lo
    iface lo inet loopback
    
    auto eth0
    iface eth0 inet manual
      up ip link set eth0 up
    
    auto br0
    iface br0 inet static
      bridge_ports eth0
      address 192.168.1.11
      broadcast 192.168.1.255
      netmask 255.255.255.0
      gateway 192.168.1.254
  7. reboot

SSH

To set up ssh:

  1. ssh mirage@192.168.1.11 (password: mirage)

  2. ssh-keygen

  3. logout (ctrl-d)

  4. scp ~/.ssh/id_rsa.pub mirage@192.168.1.11:.ssh/authorized_keys

  5. ssh mirage@192.168.1.11

  6. chmod 700 ~/.ssh

  7. chmod 600 ~/.ssh/authorized_keys

MirageOS

You should now have a working Xen host ("xl list" to list current VMs, "lvcreate" to create guest disks).

To install the ARM version of mirage:

opam init
opam install mirage

You should now be able to follow the rest of the MirageOS tutorial.

Libvirt

  1. To install libvirt (the precompiled version doesn't contain the drivers for xen):

    sudo apt-get install uuid-dev libxml2-dev libdevmapper-dev libpciaccess-dev \
    libnl-dev libxen-dev libgnutls-dev
  2. Download a release tarball from libvirt.org (I used 1.2.6). Download to local machine, decompress

    scp libvirt-1.2.6.tar mirage@cubieboard2:
    ssh mirage@cubieboard2
    tar xf libvirt-1.2.6.tar
    rm libvirt-1.2.6.tar
    cd libvirt-1.2.6
  3. Configure:

    ./configure --prefix=/usr --localstatedir=/var  --sysconfdir=/etc --with-xen \
    --with-qemu=no --with-gnutls --with-uml=no --with-openvz=no --with-vmware=no \
    --with-phyp=no --with-xenapi=no --with-libxl=yes --with-vbox=no --with-lxc=no \
    --with-esx=no  --with-hyperv=no --with-parallels=no --with-init-script=upstart
  4. make

  5. sudo make install

  6. Create a 'libvirt' group if one doesn't already exist

    sudo addgroup libvirt

  7. Add the two scripts (below, if they don't already exist) to /etc/init.d/libvirt-bin and /etc/default/libvirt-bin

  8. Ensure that /etc/default/libvirt-bin has '-l' to libvirtd_opts

  9. Follow the instructions in http://wiki.libvirt.org/page/TLSSetup in install tls on the cubieboards and admin machine

    • Use the libvirt group instead of qemu as the owner of /etc/pki/libvirt/
  10. System init scripts:

    cd /etc/rc5.d
    sudo ln -s ../init.d/libvirt-bin S22libvirt-bin
    
    cd /etc/rc6.d
    sudo ln -s ../init.d/libvirt-bin K19libvirt-bin
    sudo update-rc.d libvirt-bin defaults
    sudo service libvirt-bin start
  11. Reboot the board

  12. From the admin machine, edit /etc/hosts and add the cubieboard addresses and names so that (a) the names are resolvable and (b) matches the name on the certificates, e.g.

    192.168.1.10 cubieboard2

  13. Test that the admin machine can talk to the cubieboard:

    sudo virsh -c xen://cubieboard2/system hostname

    and you should get 'cubieboard2' returned, if not, ssh to the cubieboard and check/restart the daemon (sudo service libvirt-bin start)

To set up the admin machine to ensure another user (instead of root) can run virsh commands:

On the admin machine:

  1. Add the user to the libvirt group (on older releases of libvirt, this group is sometimes 'libvirtd')

  2. Ensure that the clientcert.pem and clientkey.pem in /etc/pki/libvirt belong to the libvirt group, e.g.:

    sudo chgrp libvirt /etc/pki/libvirt/clientcert.pem
    sudo chmod 440 /etc/pki/libvirt/clientcert.pem
    sudo chgrp libvirt /etc/pki/libvirt/private/clientkey.pem
    sudo chmod 440 /etc/pki/libvirt/private/clientkey.pem
  3. Edit /etc/libvirt/libvirtd.conf and ensure unix_sock_group, unix_sock_ro_perms, unix_sock_rw_perms are uncommented, allowing users in the libvirt(d) group to use tls, i.e.

    unix_sock_group = "libvirt"
    unix_sock_ro_perms = "0777"
    unix_sock_rw_perms = "0770"

On the cubieboard:

  1. ssh into the cubieboard and create a user which matches the 'admin' user ( - 'nick' in my case),

    sudo adduser 'username'

  2. Add the admin user to the libvirt group

    sudo adduser 'username' libvirt

  3. Reboot

The cubieboard should now be accessible remotely from a non-root account.

Clone the mirage example mirage-skeleton/xen/static_website+ip

Compile the example (this currently needs to be built on a cubieboard), and then edit www.xl. Change the ipaddress, gateway etc. to suit, and then run the virsh 'domxml-from-native' translator to get the libvirt xml file

virsh -c xen:/// domxml-from-native xen-xm www.xl > www.xml
virsh -c xen://cubie0/system create www.xml

/etc/default/libvirt-bin

# Defaults for libvirt-bin initscript (/etc/init.d/libvirt-bin)
# This is a POSIX shell fragment

# Start libvirtd to handle qemu/kvm:
start_libvirtd="yes"

# options passed to libvirtd, add "-l" to listen on tcp
libvirtd_opts="-d -l"

# pass in location of kerberos keytab
#export KRB5_KTNAME=/etc/libvirt/libvirt.keytab

/etc/init.d/libvirt-bin

#! /bin/sh
#
# Init script for libvirtd
#
# (c) 2007 Guido Guenther <agx@sigxcpu.org>
# based on the skeletons that comes with dh_make
#
### BEGIN INIT INFO
# Provides:          libvirt-bin libvirtd
# Required-Start:    $network $local_fs $remote_fs $syslog
# Required-Stop:     $local_fs $remote_fs $syslog
# Should-Start:      hal avahi cgconfig
# Should-Stop:       hal avahi cgconfig
# Default-Start:     2 3 4 5
# Default-Stop:      0 1 6
# Short-Description: libvirt management daemon
### END INIT INFO

PATH=/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin
DAEMON=/usr/sbin/libvirtd
NAME=libvirtd
DESC="libvirt management daemon"
export PATH

test -x $DAEMON || exit 0
. /lib/lsb/init-functions

PIDFILE=/var/run/$NAME.pid
DODTIME=1                   # Time to wait for the server to die, in seconds

# Include libvirtd defaults if available
if [ -f /etc/default/libvirt-bin ] ; then
    . /etc/default/libvirt-bin
fi

check_start_libvirtd_option() {
  if [ ! "$start_libvirtd" = "yes" ]; then
    log_warning_msg "Not starting libvirt management daemon libvirtd, disabled via /etc/default/libvirt-bin"
    return 1
  else
    return 0
  fi
}

running_pid()
{
    # Check if a given process pid's cmdline matches a given name
    pid=$1
    name=$2
    [ -z "$pid" ] && return 1 
    [ ! -d /proc/$pid ] &&  return 1
    cmd=`cat /proc/$pid/cmdline | tr "\000" "\n"|head -n 1 |cut -d : -f 1`
    # Is this the expected child?
    [ "$cmd" != "$name" ] &&  return 1
    return 0
}

running()
{
# Check if the process is running looking at /proc
# (works for all users)
    # No pidfile, probably no daemon present
    [ ! -f "$PIDFILE" ] && return 1
    # Obtain the pid and check it against the binary name
    pid=`cat $PIDFILE`
    running_pid $pid $DAEMON || return 1
    return 0
}

force_stop() {
# Forcefully kill the process
    [ ! -f "$PIDFILE" ] && return
    if running ; then
        kill -15 $pid
        # Is it really dead?
        [ -n "$DODTIME" ] && sleep "$DODTIME"s
        if running ; then
            kill -9 $pid
            [ -n "$DODTIME" ] && sleep "$DODTIME"s
            if running ; then
                echo "Cannot kill $LABEL (pid=$pid)!"
                exit 1
            fi
        fi
    fi
    rm -f $PIDFILE
    return 0
}

case "$1" in
  start)
    if check_start_libvirtd_option; then
        log_daemon_msg "Starting $DESC" "$NAME"
            if running ;  then
                    log_progress_msg "already running"
                    log_end_msg 0
                    exit 0
            fi
        rm -f /var/run/libvirtd.pid
        start-stop-daemon --start --quiet --pidfile $PIDFILE \
            --exec $DAEMON -- $libvirtd_opts
        if running; then
            log_end_msg 0
        else
            log_end_msg 1
        fi
    fi
    ;;
  stop)
    log_daemon_msg "Stopping $DESC" "$NAME"
    if ! running ;  then
               log_progress_msg "not running"
                log_end_msg 0
                exit 0
           fi
    start-stop-daemon --stop --quiet --pidfile $PIDFILE \
        --exec $DAEMON
    log_end_msg 0
    ;;
  force-stop)
    log_daemon_msg "Forcefully stopping $DESC" "$NAME"
    force_stop
    if ! running; then
        log_end_msg 0
    else
        log_end_msg 1
    fi
    ;;
  restart)
    if check_start_libvirtd_option; then
        log_daemon_msg "Restarting $DESC" "$DAEMON"
        start-stop-daemon --oknodo --stop --quiet --pidfile \
            /var/run/$NAME.pid --exec $DAEMON
        [ -n "$DODTIME" ] && sleep $DODTIME
        start-stop-daemon --start --quiet --pidfile \
            /var/run/$NAME.pid --exec $DAEMON -- $libvirtd_opts
        if running; then
            log_end_msg 0
        else
            log_end_msg 1
        fi
    fi
    ;;
  reload|force-reload)
      if running; then
            log_daemon_msg "Reloading configuration of $DESC" "$NAME"
        start-stop-daemon --stop --signal 1 --quiet --pidfile \
                 /var/run/$NAME.pid --exec $DAEMON
        log_end_msg 0
    else
            log_warning_msg "libvirtd not running, doing nothing."
    fi
    ;;
  status)
        log_daemon_msg "Checking status of $DESC" "$NAME"
        if running ;  then
            log_progress_msg "running"
            log_end_msg 0
        else
            log_progress_msg "not running"
            log_end_msg 1
            if [ -f "$PIDFILE" ] ; then
                exit 1
            else
                exit 3
            fi
    fi
    ;;
  *)
    N=/etc/init.d/libvirt-bin
    echo "Usage: $N {start|stop|restart|reload|force-reload|status|force-stop}" >&2
    exit 1
    ;;
esac

exit 0