lib/nova

# lib/nova
# Functions to control the configuration and operation of the **Nova** service

# Dependencies:
# ``functions`` file
# ``DEST``, ``DATA_DIR``, ``STACK_USER`` must be defined
# ``SERVICE_{TENANT_NAME|PASSWORD}`` must be defined
# ``LIBVIRT_TYPE`` must be defined
# ``INSTANCE_NAME_PREFIX``, ``VOLUME_NAME_PREFIX`` must be defined
# ``KEYSTONE_TOKEN_FORMAT`` must be defined

# ``stack.sh`` calls the entry points in this order:
#
# install_nova
# configure_nova
# create_nova_conf
# init_nova
# start_nova
# stop_nova
# cleanup_nova

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


# Defaults
# --------

# Set up default directories
NOVA_DIR=$DEST/nova
NOVACLIENT_DIR=$DEST/python-novaclient
NOVA_STATE_PATH=${NOVA_STATE_PATH:=$DATA_DIR/nova}
# INSTANCES_PATH is the previous name for this
NOVA_INSTANCES_PATH=${NOVA_INSTANCES_PATH:=${INSTANCES_PATH:=$NOVA_STATE_PATH/instances}}
NOVA_AUTH_CACHE_DIR=${NOVA_AUTH_CACHE_DIR:-/var/cache/nova}

NOVA_CONF_DIR=/etc/nova
NOVA_CONF=$NOVA_CONF_DIR/nova.conf
NOVA_API_PASTE_INI=${NOVA_API_PASTE_INI:-$NOVA_CONF_DIR/api-paste.ini}

# Public facing bits
NOVA_SERVICE_HOST=${NOVA_SERVICE_HOST:-$SERVICE_HOST}
NOVA_SERVICE_PORT=${NOVA_SERVICE_PORT:-8774}
NOVA_SERVICE_PORT_INT=${NOVA_SERVICE_PORT_INT:-18774}
NOVA_SERVICE_PROTOCOL=${NOVA_SERVICE_PROTOCOL:-$SERVICE_PROTOCOL}

# Support entry points installation of console scripts
if [[ -d $NOVA_DIR/bin ]]; then
    NOVA_BIN_DIR=$NOVA_DIR/bin
else
    NOVA_BIN_DIR=$(get_python_exec_prefix)
fi

# Set the paths of certain binaries
NOVA_ROOTWRAP=$(get_rootwrap_location nova)

# Allow rate limiting to be turned off for testing, like for Tempest
# NOTE: Set API_RATE_LIMIT="False" to turn OFF rate limiting
API_RATE_LIMIT=${API_RATE_LIMIT:-"True"}

# Nova supports pluggable schedulers.  The default ``FilterScheduler``
# should work in most cases.
SCHEDULER=${SCHEDULER:-nova.scheduler.filter_scheduler.FilterScheduler}

QEMU_CONF=/etc/libvirt/qemu.conf


# Entry Points
# ------------

function add_nova_opt {
    echo "$1" >>$NOVA_CONF
}

# Helper to clean iptables rules
function clean_iptables() {
    # Delete rules
    sudo iptables -S -v | sed "s/-c [0-9]* [0-9]* //g" | grep "nova" | grep "\-A" |  sed "s/-A/-D/g" | awk '{print "sudo iptables",$0}' | bash
    # Delete nat rules
    sudo iptables -S -v -t nat | sed "s/-c [0-9]* [0-9]* //g" | grep "nova" |  grep "\-A" | sed "s/-A/-D/g" | awk '{print "sudo iptables -t nat",$0}' | bash
    # Delete chains
    sudo iptables -S -v | sed "s/-c [0-9]* [0-9]* //g" | grep "nova" | grep "\-N" |  sed "s/-N/-X/g" | awk '{print "sudo iptables",$0}' | bash
    # Delete nat chains
    sudo iptables -S -v -t nat | sed "s/-c [0-9]* [0-9]* //g" | grep "nova" |  grep "\-N" | sed "s/-N/-X/g" | awk '{print "sudo iptables -t nat",$0}' | bash
}

# cleanup_nova() - Remove residual data files, anything left over from previous
# runs that a clean run would need to clean up
function cleanup_nova() {
    if is_service_enabled n-cpu; then
        # Clean iptables from previous runs
        clean_iptables

        # Destroy old instances
        instances=`sudo virsh list --all | grep $INSTANCE_NAME_PREFIX | sed "s/.*\($INSTANCE_NAME_PREFIX[0-9a-fA-F]*\).*/\1/g"`
        if [ ! "$instances" = "" ]; then
            echo $instances | xargs -n1 sudo virsh destroy || true
            echo $instances | xargs -n1 sudo virsh undefine || true
        fi

        # Logout and delete iscsi sessions
        sudo iscsiadm --mode node | grep $VOLUME_NAME_PREFIX | cut -d " " -f2 | xargs sudo iscsiadm --mode node --logout || true
        sudo iscsiadm --mode node | grep $VOLUME_NAME_PREFIX | cut -d " " -f2 | sudo iscsiadm --mode node --op delete || true

        # Clean out the instances directory.
        sudo rm -rf $NOVA_INSTANCES_PATH/*
    fi

    sudo rm -rf $NOVA_STATE_PATH $NOVA_AUTH_CACHE_DIR
}

# configure_novaclient() - Set config files, create data dirs, etc
function configure_novaclient() {
    setup_develop $NOVACLIENT_DIR
}

# configure_nova_rootwrap() - configure Nova's rootwrap
function configure_nova_rootwrap() {
    # Deploy new rootwrap filters files (owned by root).
    # Wipe any existing rootwrap.d files first
    if [[ -d $NOVA_CONF_DIR/rootwrap.d ]]; then
        sudo rm -rf $NOVA_CONF_DIR/rootwrap.d
    fi
    # Deploy filters to /etc/nova/rootwrap.d
    sudo mkdir -m 755 $NOVA_CONF_DIR/rootwrap.d
    sudo cp $NOVA_DIR/etc/nova/rootwrap.d/*.filters $NOVA_CONF_DIR/rootwrap.d
    sudo chown -R root:root $NOVA_CONF_DIR/rootwrap.d
    sudo chmod 644 $NOVA_CONF_DIR/rootwrap.d/*
    # Set up rootwrap.conf, pointing to /etc/nova/rootwrap.d
    sudo cp $NOVA_DIR/etc/nova/rootwrap.conf $NOVA_CONF_DIR/
    sudo sed -e "s:^filters_path=.*$:filters_path=$NOVA_CONF_DIR/rootwrap.d:" -i $NOVA_CONF_DIR/rootwrap.conf
    sudo chown root:root $NOVA_CONF_DIR/rootwrap.conf
    sudo chmod 0644 $NOVA_CONF_DIR/rootwrap.conf
    # Specify rootwrap.conf as first parameter to nova-rootwrap
    ROOTWRAP_SUDOER_CMD="$NOVA_ROOTWRAP $NOVA_CONF_DIR/rootwrap.conf *"

    # Set up the rootwrap sudoers for nova
    TEMPFILE=`mktemp`
    echo "$USER ALL=(root) NOPASSWD: $ROOTWRAP_SUDOER_CMD" >$TEMPFILE
    chmod 0440 $TEMPFILE
    sudo chown root:root $TEMPFILE
    sudo mv $TEMPFILE /etc/sudoers.d/nova-rootwrap
}

# configure_nova() - Set config files, create data dirs, etc
function configure_nova() {
    setup_develop $NOVA_DIR

    # Put config files in ``/etc/nova`` for everyone to find
    if [[ ! -d $NOVA_CONF_DIR ]]; then
        sudo mkdir -p $NOVA_CONF_DIR
    fi
    sudo chown $STACK_USER $NOVA_CONF_DIR

    cp -p $NOVA_DIR/etc/nova/policy.json $NOVA_CONF_DIR

    configure_nova_rootwrap

    if is_service_enabled n-api; then
        # Use the sample http middleware configuration supplied in the
        # Nova sources.  This paste config adds the configuration required
        # for Nova to validate Keystone tokens.

        # Remove legacy paste config if present
        rm -f $NOVA_DIR/bin/nova-api-paste.ini

        # Get the sample configuration file in place
        cp $NOVA_DIR/etc/nova/api-paste.ini $NOVA_CONF_DIR

        iniset $NOVA_API_PASTE_INI filter:authtoken auth_host $SERVICE_HOST
        if is_service_enabled tls-proxy; then
            iniset $NOVA_API_PASTE_INI filter:authtoken auth_protocol $SERVICE_PROTOCOL
        fi
        iniset $NOVA_API_PASTE_INI filter:authtoken admin_tenant_name $SERVICE_TENANT_NAME
        iniset $NOVA_API_PASTE_INI filter:authtoken admin_user nova
        iniset $NOVA_API_PASTE_INI filter:authtoken admin_password $SERVICE_PASSWORD
    fi

    iniset $NOVA_API_PASTE_INI filter:authtoken signing_dir $NOVA_AUTH_CACHE_DIR

    if is_service_enabled n-cpu; then
        # Force IP forwarding on, just on case
        sudo sysctl -w net.ipv4.ip_forward=1

        # Attempt to load modules: network block device - used to manage qcow images
        sudo modprobe nbd || true

        # Check for kvm (hardware based virtualization).  If unable to initialize
        # kvm, we drop back to the slower emulation mode (qemu).  Note: many systems
        # come with hardware virtualization disabled in BIOS.
        if [[ "$LIBVIRT_TYPE" == "kvm" ]]; then
            sudo modprobe kvm || true
            if [ ! -e /dev/kvm ]; then
                echo "WARNING: Switching to QEMU"
                LIBVIRT_TYPE=qemu
                if which selinuxenabled 2>&1 > /dev/null && selinuxenabled; then
                    # https://bugzilla.redhat.com/show_bug.cgi?id=753589
                    sudo setsebool virt_use_execmem on
                fi
            fi
        fi

        # Install and configure **LXC** if specified.  LXC is another approach to
        # splitting a system into many smaller parts.  LXC uses cgroups and chroot
        # to simulate multiple systems.
        if [[ "$LIBVIRT_TYPE" == "lxc" ]]; then
            if is_ubuntu; then
                if [[ ! "$DISTRO" > natty ]]; then
                    cgline="none /cgroup cgroup cpuacct,memory,devices,cpu,freezer,blkio 0 0"
                    sudo mkdir -p /cgroup
                    if ! grep -q cgroup /etc/fstab; then
                        echo "$cgline" | sudo tee -a /etc/fstab
                    fi
                    if ! mount -n | grep -q cgroup; then
                        sudo mount /cgroup
                    fi
                fi
            fi
        fi

        # Prepare directories and packages for baremetal driver
        if is_baremetal; then
            configure_baremetal_nova_dirs
        fi

        if is_service_enabled quantum && is_quantum_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

        if is_ubuntu; then
            LIBVIRT_DAEMON=libvirt-bin
        else
            LIBVIRT_DAEMON=libvirtd
        fi



        if is_fedora; then
            # Starting with fedora 18 enable stack-user to virsh -c qemu:///system
            # by creating a policy-kit rule for stack-user
            if [[ "$os_RELEASE" -ge "18" ]]; then
                rules_dir=/etc/polkit-1/rules.d
                sudo mkdir -p $rules_dir
                sudo bash -c "cat <<EOF > $rules_dir/50-libvirt-$STACK_USER.rules
polkit.addRule(function(action, subject) {
     if (action.id == 'org.libvirt.unix.manage' &&
         subject.user == '"$STACK_USER"') {
         return polkit.Result.YES;
     }
});
EOF"
                unset rules_dir
            else
                sudo bash -c 'cat <<EOF >/etc/polkit-1/localauthority/50-local.d/50-libvirt-remote-access.pkla
[libvirt Management Access]
Identity=unix-group:libvirtd
Action=org.libvirt.unix.manage
ResultAny=yes
ResultInactive=yes
ResultActive=yes
EOF'
            fi
        elif is_suse; then
            # Work around the fact that polkit-default-privs overrules pklas
            # with 'unix-group:$group'.
            sudo bash -c "cat <<EOF >/etc/polkit-1/localauthority/50-local.d/50-libvirt-remote-access.pkla
[libvirt Management Access]
Identity=unix-user:$USER
Action=org.libvirt.unix.manage
ResultAny=yes
ResultInactive=yes
ResultActive=yes
EOF"
        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 libvirtd >/dev/null; then
            sudo groupadd libvirtd
        fi
        add_user_to_group $STACK_USER libvirtd

        # libvirt detects various settings on startup, as we potentially changed
        # the system configuration (modules, filesystems), we need to restart
        # libvirt to detect those changes.
        restart_service $LIBVIRT_DAEMON


        # Instance Storage
        # ----------------

        # Nova stores each instance in its own directory.
        mkdir -p $NOVA_INSTANCES_PATH

        # You can specify a different disk to be mounted and used for backing the
        # virtual machines.  If there is a partition labeled nova-instances we
        # mount it (ext filesystems can be labeled via e2label).
        if [ -L /dev/disk/by-label/nova-instances ]; then
            if ! mount -n | grep -q $NOVA_INSTANCES_PATH; then
                sudo mount -L nova-instances $NOVA_INSTANCES_PATH
                sudo chown -R $STACK_USER $NOVA_INSTANCES_PATH
            fi
        fi
    fi
}

# create_nova_accounts() - Set up common required nova accounts

# Tenant               User       Roles
# ------------------------------------------------------------------
# service              nova       admin, [ResellerAdmin (swift only)]

# Migrated from keystone_data.sh
create_nova_accounts() {

    SERVICE_TENANT=$(keystone tenant-list | awk "/ $SERVICE_TENANT_NAME / { print \$2 }")
    ADMIN_ROLE=$(keystone role-list | awk "/ admin / { print \$2 }")

    # Nova
    if [[ "$ENABLED_SERVICES" =~ "n-api" ]]; then
        NOVA_USER=$(keystone user-create \
            --name=nova \
            --pass="$SERVICE_PASSWORD" \
            --tenant_id $SERVICE_TENANT \
            --email=nova@example.com \
            | grep " id " | get_field 2)
        keystone user-role-add \
            --tenant_id $SERVICE_TENANT \
            --user_id $NOVA_USER \
            --role_id $ADMIN_ROLE
        if [[ "$KEYSTONE_CATALOG_BACKEND" = 'sql' ]]; then
            NOVA_SERVICE=$(keystone service-create \
                --name=nova \
                --type=compute \
                --description="Nova Compute Service" \
                | grep " id " | get_field 2)
            keystone endpoint-create \
                --region RegionOne \
                --service_id $NOVA_SERVICE \
                --publicurl "$NOVA_SERVICE_PROTOCOL://$NOVA_SERVICE_HOST:$NOVA_SERVICE_PORT/v2/\$(tenant_id)s" \
                --adminurl "$NOVA_SERVICE_PROTOCOL://$NOVA_SERVICE_HOST:$NOVA_SERVICE_PORT/v2/\$(tenant_id)s" \
                --internalurl "$NOVA_SERVICE_PROTOCOL://$NOVA_SERVICE_HOST:$NOVA_SERVICE_PORT/v2/\$(tenant_id)s"
        fi
    fi
}

# create_nova_conf() - Create a new nova.conf file
function create_nova_conf() {
    # Remove legacy ``nova.conf``
    rm -f $NOVA_DIR/bin/nova.conf

    # (Re)create ``nova.conf``
    rm -f $NOVA_CONF
    add_nova_opt "[DEFAULT]"
    iniset $NOVA_CONF DEFAULT verbose "True"
    iniset $NOVA_CONF DEFAULT debug "True"
    iniset $NOVA_CONF DEFAULT auth_strategy "keystone"
    iniset $NOVA_CONF DEFAULT allow_resize_to_same_host "True"
    iniset $NOVA_CONF DEFAULT api_paste_config "$NOVA_API_PASTE_INI"
    iniset $NOVA_CONF DEFAULT rootwrap_config "$NOVA_CONF_DIR/rootwrap.conf"
    iniset $NOVA_CONF DEFAULT compute_scheduler_driver "$SCHEDULER"
    iniset $NOVA_CONF DEFAULT dhcpbridge_flagfile "$NOVA_CONF"
    iniset $NOVA_CONF DEFAULT force_dhcp_release "True"
    iniset $NOVA_CONF DEFAULT fixed_range ""
    iniset $NOVA_CONF DEFAULT default_floating_pool "$PUBLIC_NETWORK_NAME"
    iniset $NOVA_CONF DEFAULT s3_host "$SERVICE_HOST"
    iniset $NOVA_CONF DEFAULT s3_port "$S3_SERVICE_PORT"
    iniset $NOVA_CONF DEFAULT osapi_compute_extension "nova.api.openstack.compute.contrib.standard_extensions"
    iniset $NOVA_CONF DEFAULT my_ip "$HOST_IP"
    iniset $NOVA_CONF DEFAULT sql_connection `database_connection_url nova`
    if is_baremetal; then
        iniset $NOVA_CONF baremetal sql_connection `database_connection_url nova_bm`
    fi
    iniset $NOVA_CONF DEFAULT libvirt_type "$LIBVIRT_TYPE"
    iniset $NOVA_CONF DEFAULT libvirt_cpu_mode "none"
    iniset $NOVA_CONF DEFAULT instance_name_template "${INSTANCE_NAME_PREFIX}%08x"

    if is_service_enabled n-api; then
        iniset $NOVA_CONF DEFAULT enabled_apis "$NOVA_ENABLED_APIS"
        if is_service_enabled tls-proxy; then
            # Set the service port for a proxy to take the original
            iniset $NOVA_CONF DEFAULT osapi_compute_listen_port "$NOVA_SERVICE_PORT_INT"
        fi
    fi
    if is_service_enabled cinder; then
        iniset $NOVA_CONF DEFAULT volume_api_class "nova.volume.cinder.API"
    fi
    if [ -n "$NOVA_STATE_PATH" ]; then
        iniset $NOVA_CONF DEFAULT state_path "$NOVA_STATE_PATH"
        iniset $NOVA_CONF DEFAULT lock_path "$NOVA_STATE_PATH"
    fi
    if [ -n "$NOVA_INSTANCES_PATH" ]; then
        iniset $NOVA_CONF DEFAULT instances_path "$NOVA_INSTANCES_PATH"
    fi
    if [ "$MULTI_HOST" != "False" ]; then
        iniset $NOVA_CONF DEFAULT multi_host "True"
        iniset $NOVA_CONF DEFAULT send_arp_for_ha "True"
    fi
    if [ "$SYSLOG" != "False" ]; then
        iniset $NOVA_CONF DEFAULT use_syslog "True"
    fi
    if [ "$API_RATE_LIMIT" != "True" ]; then
        iniset $NOVA_CONF DEFAULT api_rate_limit "False"
    fi
    if [ "$LOG_COLOR" == "True" ] && [ "$SYSLOG" == "False" ]; then
        # Add color to logging output
        iniset $NOVA_CONF DEFAULT logging_context_format_string "%(asctime)s.%(msecs)03d %(color)s%(levelname)s %(name)s [%(request_id)s %(user_name)s %(project_name)s%(color)s] %(instance)s%(color)s%(message)s"
        iniset $NOVA_CONF DEFAULT logging_default_format_string "%(asctime)s.%(msecs)03d %(color)s%(levelname)s %(name)s [-%(color)s] %(instance)s%(color)s%(message)s"
        iniset $NOVA_CONF DEFAULT logging_debug_format_suffix "from (pid=%(process)d) %(funcName)s %(pathname)s:%(lineno)d"
        iniset $NOVA_CONF DEFAULT logging_exception_prefix "%(color)s%(asctime)s.%(msecs)03d TRACE %(name)s %(instance)s"
    else
        # Show user_name and project_name instead of user_id and project_id
        iniset $NOVA_CONF DEFAULT logging_context_format_string "%(asctime)s.%(msecs)03d %(levelname)s %(name)s [%(request_id)s %(user_name)s %(project_name)s] %(instance)s%(message)s"
    fi
    if is_service_enabled ceilometer; then
        iniset $NOVA_CONF DEFAULT instance_usage_audit "True"
        iniset $NOVA_CONF DEFAULT instance_usage_audit_period "hour"
        iniset_multiline $NOVA_CONF DEFAULT notification_driver "nova.openstack.common.notifier.rpc_notifier" "ceilometer.compute.nova_notifier"
    fi


    # Provide some transition from ``EXTRA_FLAGS`` to ``EXTRA_OPTS``
    if [[ -z "$EXTRA_OPTS" && -n "$EXTRA_FLAGS" ]]; then
        EXTRA_OPTS=$EXTRA_FLAGS
    fi

    # Define extra nova conf flags by defining the array ``EXTRA_OPTS``.
    # For Example: ``EXTRA_OPTS=(foo=true bar=2)``
    for I in "${EXTRA_OPTS[@]}"; do
        # Replace the first '=' with ' ' for iniset syntax
        iniset $NOVA_CONF DEFAULT ${I/=/ }
    done
}

# create_nova_cache_dir() - Part of the init_nova() process
function create_nova_cache_dir() {
    # Create cache dir
    sudo mkdir -p $NOVA_AUTH_CACHE_DIR
    sudo chown $STACK_USER $NOVA_AUTH_CACHE_DIR
    rm -f $NOVA_AUTH_CACHE_DIR/*
}

function create_nova_conf_nova_network() {
    iniset $NOVA_CONF DEFAULT network_manager "nova.network.manager.$NET_MAN"
    iniset $NOVA_CONF DEFAULT public_interface "$PUBLIC_INTERFACE"
    iniset $NOVA_CONF DEFAULT vlan_interface "$VLAN_INTERFACE"
    iniset $NOVA_CONF DEFAULT flat_network_bridge "$FLAT_NETWORK_BRIDGE"
    if [ -n "$FLAT_INTERFACE" ]; then
        iniset $NOVA_CONF DEFAULT flat_interface "$FLAT_INTERFACE"
    fi
}

# create_nova_keys_dir() - Part of the init_nova() process
function create_nova_keys_dir() {
    # Create keys dir
    sudo mkdir -p ${NOVA_STATE_PATH}/keys
    sudo chown -R $STACK_USER ${NOVA_STATE_PATH}
}

# init_nova() - Initialize databases, etc.
function init_nova() {
    # All nova components talk to a central database.
    # Only do this step once on the API node for an entire cluster.
    if is_service_enabled $DATABASE_BACKENDS && is_service_enabled n-api; then
        # (Re)create nova database
        # Explicitly use latin1: to avoid lp#829209, nova expects the database to
        # use latin1 by default, and then upgrades the database to utf8 (see the
        # 082_essex.py in nova)
        recreate_database nova latin1

        # Migrate nova database
        $NOVA_BIN_DIR/nova-manage db sync

        # (Re)create nova baremetal database
        if is_baremetal; then
            recreate_database nova_bm latin1
            $NOVA_BIN_DIR/nova-baremetal-manage db sync
        fi
    fi

    create_nova_cache_dir
    create_nova_keys_dir
}

# install_novaclient() - Collect source and prepare
function install_novaclient() {
    git_clone $NOVACLIENT_REPO $NOVACLIENT_DIR $NOVACLIENT_BRANCH
}

# install_nova() - Collect source and prepare
function install_nova() {
    if is_service_enabled n-cpu; then
        if is_ubuntu; then
            install_package libvirt-bin
        elif is_fedora || is_suse; then
            install_package libvirt
        else
            exit_distro_not_supported "libvirt installation"
        fi

        # Install and configure **LXC** if specified.  LXC is another approach to
        # splitting a system into many smaller parts.  LXC uses cgroups and chroot
        # to simulate multiple systems.
        if [[ "$LIBVIRT_TYPE" == "lxc" ]]; then
            if is_ubuntu; then
                if [[ "$DISTRO" > natty ]]; then
                    install_package cgroup-lite
                fi
            else
                ### FIXME(dtroyer): figure this out
                echo "RPM-based cgroup not implemented yet"
                yum_install libcgroup-tools
            fi
        fi
    fi

    git_clone $NOVA_REPO $NOVA_DIR $NOVA_BRANCH
}

# start_nova_api() - Start the API process ahead of other things
function start_nova_api() {
    # Get right service port for testing
    local service_port=$NOVA_SERVICE_PORT
    if is_service_enabled tls-proxy; then
        service_port=$NOVA_SERVICE_PORT_INT
    fi

    screen_it n-api "cd $NOVA_DIR && $NOVA_BIN_DIR/nova-api"
    echo "Waiting for nova-api to start..."
    if ! wait_for_service $SERVICE_TIMEOUT http://$SERVICE_HOST:$service_port; then
      die $LINENO "nova-api did not start"
    fi

    # Start proxies if enabled
    if is_service_enabled tls-proxy; then
        start_tls_proxy '*' $NOVA_SERVICE_PORT $NOVA_SERVICE_HOST $NOVA_SERVICE_PORT_INT &
    fi
}

# start_nova() - Start running processes, including screen
function start_nova() {
    # The group **libvirtd** is added to the current user in this script.
    # Use 'sg' to execute nova-compute as a member of the **libvirtd** group.
    # ``screen_it`` checks ``is_service_enabled``, it is not needed here
    screen_it n-cond "cd $NOVA_DIR && $NOVA_BIN_DIR/nova-conductor"
    screen_it n-cpu "cd $NOVA_DIR && sg libvirtd $NOVA_BIN_DIR/nova-compute"
    screen_it n-crt "cd $NOVA_DIR && $NOVA_BIN_DIR/nova-cert"
    screen_it n-net "cd $NOVA_DIR && $NOVA_BIN_DIR/nova-network"
    screen_it n-sch "cd $NOVA_DIR && $NOVA_BIN_DIR/nova-scheduler"
    screen_it n-novnc "cd $NOVA_DIR && $NOVA_BIN_DIR/nova-novncproxy --config-file $NOVA_CONF --web $NOVNC_DIR"
    screen_it n-xvnc "cd $NOVA_DIR && $NOVA_BIN_DIR/nova-xvpvncproxy --config-file $NOVA_CONF"
    screen_it n-spice "cd $NOVA_DIR && $NOVA_BIN_DIR/nova-spicehtml5proxy --config-file $NOVA_CONF --web $SPICE_DIR"
    screen_it n-cauth "cd $NOVA_DIR && $NOVA_BIN_DIR/nova-consoleauth"
}

# stop_nova() - Stop running processes (non-screen)
function stop_nova() {
    # Kill the nova screen windows
    for serv in n-api n-cpu n-crt n-net n-sch n-novnc n-xvnc n-cauth n-cond n-spice; do
        screen -S $SCREEN_NAME -p $serv -X kill
    done
}

# Restore xtrace
$XTRACE