devstack/lib/nova_plugins/functions-libvirt

#!/bin/bash
#
# lib/nova_plugins/functions-libvirt
# Common libvirt configuration functions

# Dependencies:
# ``functions`` file
# ``STACK_USER`` has to be defined

# Save trace setting
LV_XTRACE=$(set +o | grep xtrace)
set +o xtrace

# Defaults
# --------

# Turn on selective debug log filters for libvirt.
# (NOTE: Enabling this by default, because the log filters enabled in
# 'configure_libvirt' function further below are _selective_ and not
# extremely verbose.)
DEBUG_LIBVIRT=$(trueorfalse True DEBUG_LIBVIRT)

# Installs required distro-specific libvirt packages.
function install_libvirt {
    if is_ubuntu; then
        if is_arch "aarch64" && [[ ${DISTRO} =~ (trusty|utopic) ]]; then
            install_package qemu-system
        else
            install_package qemu-kvm
            install_package libguestfs0
        fi
        install_package libvirt-bin libvirt-dev
        pip_install_gr libvirt-python
        #pip_install_gr <there-si-no-guestfs-in-pypi>
    elif is_fedora || is_suse; then
        install_package kvm
        # there is a dependency issue with kvm (which is really just a
        # wrapper to qemu-system-x86) that leaves some bios files out,
        # so install qemu-kvm (which shouldn't strictly be needed, as
        # everything has been merged into qemu-system-x86) to bring in
        # the right packages. see
        # https://bugzilla.redhat.com/show_bug.cgi?id=1235890
        install_package qemu-kvm
        install_package libvirt libvirt-devel
        pip_install_gr libvirt-python
    fi
}

# Configures the installed libvirt system so that is accessible by
# STACK_USER via qemu:///system with management capabilities.
function configure_libvirt {
    if is_service_enabled neutron && is_neutron_ovs_base_plugin && ! sudo grep -q '^cgroup_device_acl' $QEMU_CONF; then
        # Add /dev/net/tun to cgroup_device_acls, needed for type=ethernet interfaces
        cat <<EOF | sudo tee -a $QEMU_CONF
cgroup_device_acl = [
    "/dev/null", "/dev/full", "/dev/zero",
    "/dev/random", "/dev/urandom",
    "/dev/ptmx", "/dev/kvm", "/dev/kqemu",
    "/dev/rtc", "/dev/hpet","/dev/net/tun",
]
EOF
    fi

    # Since the release of Debian Wheezy the libvirt init script is libvirtd
    # and not libvirtd-bin anymore.
    if is_ubuntu && [ ! -f /etc/init.d/libvirtd ]; then
        LIBVIRT_DAEMON=libvirt-bin
    else
        LIBVIRT_DAEMON=libvirtd
    fi

    if is_fedora || is_suse; then
        # Starting with fedora 18 and opensuse-12.3 enable stack-user to
        # virsh -c qemu:///system by creating a policy-kit rule for
        # stack-user using the new Javascript syntax
        rules_dir=/etc/polkit-1/rules.d
        sudo mkdir -p $rules_dir
        cat <<EOF | sudo tee $rules_dir/50-libvirt-$STACK_USER.rules
polkit.addRule(function(action, subject) {
    if (action.id == 'org.libvirt.unix.manage' &&
        subject.user == '$STACK_USER') {
        return polkit.Result.YES;
    }
});
EOF
        unset rules_dir
    fi

    # The user that nova runs as needs to be member of **libvirtd** group otherwise
    # nova-compute will be unable to use libvirt.
    if ! getent group $LIBVIRT_GROUP >/dev/null; then
        sudo groupadd $LIBVIRT_GROUP
    fi
    add_user_to_group $STACK_USER $LIBVIRT_GROUP

    # Enable server side traces for libvirtd
    if [[ "$DEBUG_LIBVIRT" = "True" ]] ; then
        if is_ubuntu; then
            # Unexpectedly binary package builds in ubuntu get fully qualified
            # source file paths, not relative paths. This screws with the matching
            # of '1:libvirt' making everything turn on. So use libvirt.c for now.
            # This will have to be re-visited when Ubuntu ships libvirt >= 1.2.3
            local log_filters="1:libvirt.c 1:qemu 1:conf 1:security 3:object 3:event 3:json 3:file 1:util 1:qemu_monitor"
        else
            local log_filters="1:libvirt 1:qemu 1:conf 1:security 3:object 3:event 3:json 3:file 1:util 1:qemu_monitor"
        fi
        local log_outputs="1:file:/var/log/libvirt/libvirtd.log"
        if ! grep -q "log_filters=\"$log_filters\"" /etc/libvirt/libvirtd.conf; then
            echo "log_filters=\"$log_filters\"" | sudo tee -a /etc/libvirt/libvirtd.conf
        fi
        if ! grep -q "log_outputs=\"$log_outputs\"" /etc/libvirt/libvirtd.conf; then
            echo "log_outputs=\"$log_outputs\"" | sudo tee -a /etc/libvirt/libvirtd.conf
        fi
    fi

    # Update the libvirt cpu map with a gate64 cpu model. This enables nova
    # live migration for 64bit guest OSes on heterogenous cloud "hardware".
    if [[ -f /usr/share/libvirt/cpu_map.xml ]] ; then
        sudo $TOP_DIR/tools/cpu_map_update.py /usr/share/libvirt/cpu_map.xml
    fi

    # libvirt detects various settings on startup, as we potentially changed
    # the system configuration (modules, filesystems), we need to restart
    # libvirt to detect those changes. Use a stop start as otherwise the new
    # cpu_map is not loaded properly on some systems (Ubuntu).
    stop_service $LIBVIRT_DAEMON
    start_service $LIBVIRT_DAEMON
}


# Restore xtrace
$LV_XTRACE

# Local variables:
# mode: shell-script
# End: