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
_XTRACE_NOVA_FN_LIBVIRT=$(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)

# Try to enable coredumps for libvirt
# Currently fairly specific to OpenStackCI hosts
DEBUG_LIBVIRT_COREDUMPS=$(trueorfalse False DEBUG_LIBVIRT_COREDUMPS)

# Only Xenial is left with libvirt-bin.  Everywhere else is libvirtd
if is_ubuntu && [ ! -f /etc/init.d/libvirtd ]; then
    LIBVIRT_DAEMON=libvirt-bin
else
    LIBVIRT_DAEMON=libvirtd
fi

# Enable coredumps for libvirt
#  Bug: https://bugs.launchpad.net/nova/+bug/1643911
function _enable_coredump {
    local confdir=/etc/systemd/system/${LIBVIRT_DAEMON}.service.d
    local conffile=${confdir}/coredump.conf

    # Create a coredump directory, and instruct the kernel to save to
    # here
    sudo mkdir -p /var/core
    sudo chmod a+wrx /var/core
    echo '/var/core/core.%e.%p.%h.%t' | \
        sudo tee /proc/sys/kernel/core_pattern

    # Drop a config file to up the core ulimit
    sudo mkdir -p ${confdir}
    sudo tee ${conffile} <<EOF
[Service]
LimitCORE=infinity
EOF

    # Tell systemd to reload the unit (service restarts later after
    # config anyway)
    sudo systemctl daemon-reload
}


# Installs required distro-specific libvirt packages.
function install_libvirt {

    if is_ubuntu; then
        install_package qemu-system
        if [[ ${DISTRO} == "xenial" ]]; then
            install_package libvirt-bin libvirt-dev
        else
            install_package libvirt-clients libvirt-daemon-system libvirt-dev
        fi
        # uninstall in case the libvirt version changed
        pip_uninstall libvirt-python
        pip_install_gr libvirt-python
        #pip_install_gr <there-si-no-guestfs-in-pypi>
    elif is_fedora || is_suse; then
        install_package libvirt libvirt-devel
        pip_uninstall libvirt-python
        pip_install_gr libvirt-python
    fi

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

    # Service needs to be started on redhat/fedora -- do a restart for
    # sanity after fiddling the config.
    restart_service $LIBVIRT_DAEMON

    # Restart virtlogd companion service to ensure it is running properly
    #  https://bugs.launchpad.net/ubuntu/+source/libvirt/+bug/1577455
    #  https://bugzilla.redhat.com/show_bug.cgi?id=1290357
    # (not all platforms have it; libvirt 1.3+ only, thus the ignore)
    restart_service virtlogd || true
}


# Restore xtrace
$_XTRACE_NOVA_FN_LIBVIRT

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