#!/bin/bash
#
#    Licensed under the Apache License, Version 2.0 (the "License"); you may
#    not use this file except in compliance with the License. You may obtain
#    a copy of the License at
#
#         http://www.apache.org/licenses/LICENSE-2.0
#
#    Unless required by applicable law or agreed to in writing, software
#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
#    License for the specific language governing permissions and limitations
#    under the License.
#

# Global Sources
# --------------

# There are some ovs functions OVN depends on that must be sourced from
# the ovs neutron plugins. After doing this, the OVN overrides must be
# re-sourced.
source $TOP_DIR/lib/neutron_plugins/ovs_base
source $TOP_DIR/lib/neutron_plugins/openvswitch_agent


# Defaults
# --------

# Set variables for building OVN from source
OVN_REPO=${OVN_REPO:-https://github.com/ovn-org/ovn.git}
OVN_REPO_NAME=$(basename ${OVN_REPO} | cut -f1 -d'.')
OVN_BRANCH=${OVN_BRANCH:-master}

# Set variables for building OVS from source
OVS_REPO=${OVS_REPO:-https://github.com/openvswitch/ovs.git}
OVS_REPO_NAME=$(basename ${OVS_REPO} | cut -f1 -d'.')
OVS_BRANCH=$OVN_BRANCH

# How to connect to ovsdb-server hosting the OVN SB database.
OVN_SB_REMOTE=${OVN_SB_REMOTE:-tcp:$SERVICE_HOST:6642}

# How to connect to ovsdb-server hosting the OVN NB database
OVN_NB_REMOTE=${OVN_NB_REMOTE:-tcp:$SERVICE_HOST:6641}

# ml2/config for neutron_sync_mode
OVN_NEUTRON_SYNC_MODE=${OVN_NEUTRON_SYNC_MODE:-log}

# Configured DNS servers to be used with internal_dns extension, only
# if the subnet DNS is not configured.
OVN_DNS_SERVERS=${OVN_DNS_SERVERS:-8.8.8.8}

# The type of OVN L3 Scheduler to use. The OVN L3 Scheduler determines the
# hypervisor/chassis where a routers gateway should be hosted in OVN. The
# default OVN L3 scheduler is leastloaded
OVN_L3_SCHEDULER=${OVN_L3_SCHEDULER:-leastloaded}

# A UUID to uniquely identify this system.  If one is not specified, a random
# one will be generated.  A randomly generated UUID will be saved in a file
# 'ovn-uuid' so that the same one will be re-used if you re-run DevStack.
OVN_UUID=${OVN_UUID:-}

# Whether or not to build the openvswitch kernel module from ovs.  This is required
# unless the distro kernel includes ovs+conntrack support.
OVN_BUILD_MODULES=$(trueorfalse False OVN_BUILD_MODULES)

# Whether or not to install the ovs python module from ovs source.  This can be
# used to test and validate new ovs python features.  This should only be used
# for development purposes since the ovs python version is controlled by OpenStack
# requirements.
OVN_INSTALL_OVS_PYTHON_MODULE=$(trueorfalse False OVN_INSTALL_OVS_PYTHON_MODULE)

# GENEVE overlay protocol overhead. Defaults to 38 bytes plus the IP version
# overhead (20 bytes for IPv4 (default) or 40 bytes for IPv6) which is determined
# based on the ML2 overlay_ip_version option. The ML2 framework will use this to
# configure the MTU DHCP option.
OVN_GENEVE_OVERHEAD=${OVN_GENEVE_OVERHEAD:-38}

# The log level of the OVN databases (north and south)
OVN_DBS_LOG_LEVEL=${OVN_DBS_LOG_LEVEL:-info}

OVN_META_CONF=$NEUTRON_CONF_DIR/neutron_ovn_metadata_agent.ini
OVN_META_DATA_HOST=${OVN_META_DATA_HOST:-$(ipv6_unquote $SERVICE_HOST)}

# ovsdb-server wants an IPv6 address in the quoted form, [::1]
# Initialize un-quoted to handle IPv4, but add them back if version is IPv6
OVSDB_SERVER_LOCAL_HOST=$(ipv6_unquote $SERVICE_LOCAL_HOST)
if [[ "$SERVICE_IP_VERSION" == 6 ]]; then
    OVSDB_SERVER_LOCAL_HOST=[$OVSDB_SERVER_LOCAL_HOST]
fi

OVS_PREFIX=/usr/local
OVS_SBINDIR=$OVS_PREFIX/sbin
OVS_BINDIR=$OVS_PREFIX/bin
OVS_RUNDIR=$OVS_PREFIX/var/run/openvswitch
OVS_SHAREDIR=$OVS_PREFIX/share/openvswitch
OVS_SCRIPTDIR=$OVS_SHAREDIR/scripts
OVS_DATADIR=$DATA_DIR/ovs

OVN_DATADIR=$DATA_DIR/ovn
OVN_SHAREDIR=$OVS_PREFIX/share/ovn
OVN_SCRIPTDIR=$OVN_SHAREDIR/scripts
OVN_RUNDIR=$OVS_PREFIX/var/run/ovn

NEUTRON_OVN_BIN_DIR=$(get_python_exec_prefix)
NEUTRON_OVN_METADATA_BINARY="neutron-ovn-metadata-agent"

STACK_GROUP="$( id --group --name "$STACK_USER" )"


# Libs from source
# ----------------

# ovsdbapp used by neutron
GITREPO["ovsdbapp"]=${OVSDBAPP_REPO:-${GIT_BASE}/openstack/ovsdbapp.git}
GITBRANCH["ovsdbapp"]=${OVSDBAPP_BRANCH:-$TARGET_BRANCH}
GITDIR["ovsdbapp"]=$DEST/ovsdbapp


# Defaults Overwrite
# ------------------

Q_PLUGIN=${Q_PLUGIN:-"ml2"}
Q_AGENT=${Q_AGENT:-""}
Q_ML2_PLUGIN_MECHANISM_DRIVERS=${Q_ML2_PLUGIN_MECHANISM_DRIVERS:-ovn,logger}
Q_ML2_PLUGIN_TYPE_DRIVERS=${Q_ML2_PLUGIN_TYPE_DRIVERS:-local,flat,vlan,geneve}
Q_ML2_TENANT_NETWORK_TYPE=${Q_ML2_TENANT_NETWORK_TYPE:-"geneve"}
Q_ML2_PLUGIN_GENEVE_TYPE_OPTIONS=${Q_ML2_PLUGIN_GENEVE_TYPE_OPTIONS:-"vni_ranges=1:65536"}
Q_ML2_PLUGIN_EXT_DRIVERS=${Q_ML2_PLUGIN_EXT_DRIVERS:-port_security,dns}
ML2_L3_PLUGIN="ovn-router,trunk"


# Utility Functions
# -----------------

function is_kernel_module_loaded {
    if lsmod | grep $1 >& /dev/null; then
        return 0
    else
        return 1
    fi
}

function use_new_ovn_repository {
    # IF OVN_BRANCH is "master" or branch-2.13 (or higher), use the new
    # OVN repository
    return $(! printf "%s\n%s" $OVN_BRANCH branch-2.12 | sort -C -V)
}

# NOTE(rtheis): Function copied from DevStack _neutron_ovs_base_setup_bridge
# and _neutron_ovs_base_add_bridge with the call to neutron-ovs-cleanup
# removed. The call is not relevant for OVN, as it is specific to the use
# of Neutron's OVS agent and hangs when running stack.sh because
# neutron-ovs-cleanup uses the OVSDB native interface.
function ovn_base_setup_bridge {
    local bridge=$1
    local addbr_cmd="ovs-vsctl --no-wait -- --may-exist add-br $bridge"

    if [ "$OVS_DATAPATH_TYPE" != "system" ] ; then
        addbr_cmd="$addbr_cmd -- set Bridge $bridge datapath_type=${OVS_DATAPATH_TYPE}"
    fi

    $addbr_cmd
    ovs-vsctl --no-wait br-set-external-id $bridge bridge-id $bridge
}

function _start_process {
    $SYSTEMCTL daemon-reload
    $SYSTEMCTL enable $1
    $SYSTEMCTL restart $1
}

function _run_process {
    local service=$1
    local cmd="$2"
    local stop_cmd="$3"
    local group=$4
    local user=${5:-$STACK_USER}

    local systemd_service="devstack@$service.service"
    local unit_file="$SYSTEMD_DIR/$systemd_service"
    local environment="OVN_RUNDIR=$OVS_RUNDIR OVN_DBDIR=$OVN_DATADIR OVN_LOGDIR=$LOGDIR OVS_RUNDIR=$OVS_RUNDIR OVS_DBDIR=$OVS_DATADIR OVS_LOGDIR=$LOGDIR"

    echo "Starting $service executed command": $cmd

    write_user_unit_file $systemd_service "$cmd" "$group" "$user"
    iniset -sudo $unit_file "Service" "Type" "forking"
    iniset -sudo $unit_file "Service" "RemainAfterExit" "yes"
    iniset -sudo $unit_file "Service" "KillMode" "mixed"
    iniset -sudo $unit_file "Service" "LimitNOFILE" "65536"
    iniset -sudo $unit_file "Service" "Environment" "$environment"
    if [ -n "$stop_cmd" ]; then
        iniset -sudo $unit_file "Service" "ExecStop" "$stop_cmd"
    fi

    _start_process $systemd_service

    local testcmd="test -e $OVS_RUNDIR/$service.pid"
    test_with_retry "$testcmd" "$service did not start" $SERVICE_TIMEOUT 1
    sudo ovs-appctl -t $service vlog/set console:off syslog:info file:info
}

function clone_repository {
    local repo=$1
    local branch=$2
    repo_name=$(basename ${repo} | cut -f1 -d'.')

    REPO_DIR=$DEST/$repo_name

    if [ ! -d $REPO_DIR ] ; then
        git_timed clone $repo $REPO_DIR
        pushd $REPO_DIR
        git checkout $branch
        popd
    else
        # Even though the directory already exists, call git_clone to update it
        # if needed based on the RECLONE option
        git_clone $repo $REPO_DIR $branch
    fi
}

function get_ext_gw_interface {
    # Get ext_gw_interface depending on value of Q_USE_PUBLIC_VETH
    # This function is copied directly from the devstack neutron-legacy script
    if [[ "$Q_USE_PUBLIC_VETH" == "True" ]]; then
        echo $Q_PUBLIC_VETH_EX
    else
        # Disable in-band as we are going to use local port
        # to communicate with VMs
        sudo ovs-vsctl set Bridge $PUBLIC_BRIDGE \
            other_config:disable-in-band=true
        echo $PUBLIC_BRIDGE
    fi
}

function create_public_bridge {
    # Create the public bridge that OVN will use
    # This logic is based on the devstack neutron-legacy _neutron_configure_router_v4 and _v6
    local ext_gw_ifc
    ext_gw_ifc=$(get_ext_gw_interface)

    ovs-vsctl --may-exist add-br $ext_gw_ifc -- set bridge $ext_gw_ifc protocols=OpenFlow13
    ovs-vsctl set open . external-ids:ovn-bridge-mappings=$PHYSICAL_NETWORK:$ext_gw_ifc
    if [ -n "$FLOATING_RANGE" ]; then
        local cidr_len=${FLOATING_RANGE#*/}
        sudo ip addr add $PUBLIC_NETWORK_GATEWAY/$cidr_len dev $ext_gw_ifc
    fi

    # Ensure IPv6 RAs are accepted on the interface with the default route.
    # This is needed for neutron-based devstack clouds to work in
    # IPv6-only clouds in the gate. Please do not remove this without
    # talking to folks in Infra. This fix is based on a devstack fix for
    # neutron L3 agent: https://review.openstack.org/#/c/359490/.
    default_route_dev=$(ip route | grep ^default | awk '{print $5}')
    sudo sysctl -w net.ipv6.conf.$default_route_dev.accept_ra=2

    sudo sysctl -w net.ipv6.conf.all.forwarding=1
    if [ -n "$IPV6_PUBLIC_RANGE" ]; then
        local ipv6_cidr_len=${IPV6_PUBLIC_RANGE#*/}
        sudo ip -6 addr add $IPV6_PUBLIC_NETWORK_GATEWAY/$ipv6_cidr_len dev $ext_gw_ifc
        # NOTE(numans): Commenting the below code for now as this is breaking
        # the CI after xenial upgrade.
        # https://bugs.launchpad.net/networking-ovn/+bug/1648670
        # sudo ip -6 route replace $FIXED_RANGE_V6 via $IPV6_PUBLIC_NETWORK_GATEWAY dev $ext_gw_ifc
    fi

    sudo ip link set $ext_gw_ifc up
}

function _disable_libvirt_apparmor {
    if ! sudo aa-status --enabled ; then
        return 0
    fi
    # NOTE(arosen): This is used as a work around to allow newer versions
    # of libvirt to work with ovs configured ports. See LP#1466631.
    # requires the apparmor-utils
    install_package apparmor-utils
    # disables apparmor for libvirtd
    sudo aa-complain /etc/apparmor.d/usr.sbin.libvirtd
}


# OVN compilation functions
# -------------------------

# Fetch the ovs git repository and install packages needed for
# the compilation.
function _prepare_for_ovs_compilation {
    local build_modules=$1
    clone_repository $OVS_REPO $OVS_BRANCH

    if [[ "$build_modules" == "False" ]]; then
        return
    fi

    KERNEL_VERSION=`uname -r`
    if is_fedora ; then
        # is_fedora covers Fedora, RHEL, CentOS, etc...
        if [[ "$os_VENDOR" == "Fedora" ]]; then
            install_package elfutils-libelf-devel
            KERNEL_VERSION=`echo $KERNEL_VERSION | cut --delimiter='-' --field 1`
        elif [[ ${KERNEL_VERSION:0:2} != "3." ]]; then
            # dash is illegal character in rpm version so replace
            # them with underscore like it is done in the kernel
            # https://github.com/torvalds/linux/blob/master/scripts/package/mkspec#L25
            # but only for latest series of the kernel, not 3.x

            KERNEL_VERSION=`echo $KERNEL_VERSION | tr - _`
        fi

        echo NOTE: if kernel-devel-$KERNEL_VERSION or kernel-headers-$KERNEL_VERSION installation
        echo failed, please, provide a repository with the package, or yum update / reboot
        echo your machine to get the latest kernel.

        install_package kernel-devel-$KERNEL_VERSION
        install_package kernel-headers-$KERNEL_VERSION

    elif is_ubuntu ; then
        install_package linux-headers-$KERNEL_VERSION
    fi
}

# Reload the ovs kernel modules
function _reload_ovs_kernel_modules {
    ovs_system=$(sudo ovs-dpctl dump-dps | grep ovs-system)
    if [ -n "$ovs_system" ]; then
        sudo ovs-dpctl del-dp ovs-system
    fi
    sudo modprobe -r vport_geneve
    sudo modprobe -r openvswitch
    sudo modprobe openvswitch || (dmesg && die $LINENO "FAILED TO LOAD openvswitch")
    sudo modprobe vport-geneve || (dmesg && echo "FAILED TO LOAD vport-geneve")
}

# Compile openvswitch and its kernel module
function _compile_ovs {
    local build_modules=$1

    # Install the dependencies
    install_package autoconf automake libtool gcc patch make
    # TODO(flaviof): Would prefer to use pip_install wrapper, but that is not
    # useable right now because REQUIREMENTS_DIR variable is hard coded in
    # starckrc
    sudo pip3 install six

    _prepare_for_ovs_compilation $build_modules

    pushd $DEST/$OVS_REPO_NAME
    [ -f configure ] || ./boot.sh
    if [ ! -f config.status ] || [ configure -nt config.status ] ; then
        if [[ "$build_modules" == "True" ]]; then
            ./configure --with-linux=/lib/modules/$(uname -r)/build
        else
            ./configure
        fi
    fi

    make -j$(($(nproc) + 1))
    sudo make install
    if [[ "$build_modules" == "True" ]]; then
        sudo make INSTALL_MOD_DIR=kernel/net/openvswitch modules_install
        if [ $? -eq 0 ]; then
            _reload_ovs_kernel_modules
        else
            echo "Compiling OVS kernel modules failed"
        fi
    fi
    popd
}

# compile_ovn() - Compile OVN from source and load needed modules
#                 Accepts three parameters:
#                   - first optional is False by default and means that
#                     modules are built and installed.
#                   - second optional parameter defines prefix for
#                     ovn compilation
#                   - third optional parameter defines localstatedir for
#                     ovn single machine runtime
function compile_ovn {
    local build_modules=${1:-False}
    local prefix=$2
    local localstatedir=$3

    # First, compile OVS
    _compile_ovs $build_modules

    if [ -n "$prefix" ]; then
        prefix="--prefix=$prefix"
    fi

    if [ -n "$localstatedir" ]; then
        localstatedir="--localstatedir=$localstatedir"
    fi

    clone_repository $OVN_REPO $OVN_BRANCH
    pushd $DEST/$OVN_REPO_NAME

    if [ ! -f configure ] ; then
        ./boot.sh
    fi

    if [ ! -f config.status ] || [ configure -nt config.status ] ; then
        ./configure --with-ovs-source=$DEST/$OVS_REPO_NAME $prefix $localstatedir
    fi
    make -j$(($(nproc) + 1))
    sudo make install
    popd
}


# OVN Neutron driver functions
# ----------------------------

# OVN service sanity check
function ovn_sanity_check {
    if is_service_enabled q-agt neutron-agt; then
        die $LINENO "The q-agt/neutron-agt service must be disabled with OVN."
    elif is_service_enabled q-l3 neutron-l3; then
        die $LINENO "The q-l3/neutron-l3 service must be disabled with OVN."
    elif [[ ! $Q_ML2_PLUGIN_MECHANISM_DRIVERS =~ "ovn" ]]; then
        die $LINENO "OVN needs to be enabled in \$Q_ML2_PLUGIN_MECHANISM_DRIVERS"
    elif [[ ! $Q_ML2_PLUGIN_TYPE_DRIVERS =~ "geneve" ]]; then
        die $LINENO "Geneve needs to be enabled in \$Q_ML2_PLUGIN_TYPE_DRIVERS to be used with OVN"
    fi
}

# install_ovn() - Collect source and prepare
function install_ovn {
    echo "Installing OVN and dependent packages"

    # Check the OVN configuration
    ovn_sanity_check

    # If OVS is already installed, remove it, because we're about to re-install
    # it from source.
    for package in openvswitch openvswitch-switch openvswitch-common; do
        if is_package_installed $package ; then
            uninstall_package $package
        fi
    done

    # Install tox, used to generate the config (see devstack/override-defaults)
    pip_install tox
    source $NEUTRON_DIR/devstack/lib/ovs
    remove_ovs_packages
    sudo rm -f $OVS_RUNDIR/*

    if use_new_ovn_repository; then
        compile_ovn $OVN_BUILD_MODULES
    else
        compile_ovs $OVN_BUILD_MODULES
    fi

    sudo mkdir -p $OVS_RUNDIR
    sudo chown $(whoami) $OVS_RUNDIR
    sudo mkdir -p $OVS_PREFIX/var/log/openvswitch
    sudo chown $(whoami) $OVS_PREFIX/var/log/openvswitch
    sudo mkdir -p $OVS_PREFIX/var/log/ovn
    sudo chown $(whoami) $OVS_PREFIX/var/log/ovn

    # Archive log files and create new
    local log_archive_dir=$LOGDIR/archive
    mkdir -p $log_archive_dir
    for logfile in ovs-vswitchd.log ovn-northd.log ovn-controller.log ovn-controller-vtep.log ovs-vtep.log ovsdb-server.log ovsdb-server-nb.log ovsdb-server-sb.log; do
        if [ -f "$LOGDIR/$logfile" ] ; then
            mv "$LOGDIR/$logfile"  "$log_archive_dir/$logfile.${CURRENT_LOG_TIME}"
        fi
    done

    # Install ovsdbapp from source if requested
    if use_library_from_git "ovsdbapp"; then
        git_clone_by_name "ovsdbapp"
        setup_dev_lib "ovsdbapp"
    fi

    # Install ovs python module from ovs source.
    if [[ "$OVN_INSTALL_OVS_PYTHON_MODULE" == "True" ]]; then
        sudo pip uninstall -y ovs
        # Clone the OVS repository if it's not yet present
        clone_repository $OVS_REPO $OVS_BRANCH
        sudo pip install -e $DEST/$OVS_REPO_NAME/python
    fi
}

function configure_ovn_plugin {
    echo "Configuring Neutron for OVN"

    if is_service_enabled q-svc ; then
        # NOTE(arosen) needed for tempest
        export NETWORK_API_EXTENSIONS=$($PYTHON -c \
            'from neutron.common.ovn import extensions ;\
            print(",".join(extensions.ML2_SUPPORTED_API_EXTENSIONS))')
        export NETWORK_API_EXTENSIONS=$NETWORK_API_EXTENSIONS,$($PYTHON -c \
            'from neutron.common.ovn import extensions ;\
            print(",".join(extensions.ML2_SUPPORTED_API_EXTENSIONS_OVN_L3))')
        populate_ml2_config /$Q_PLUGIN_CONF_FILE ml2_type_geneve max_header_size=$OVN_GENEVE_OVERHEAD
        populate_ml2_config /$Q_PLUGIN_CONF_FILE ovn ovn_nb_connection="$OVN_NB_REMOTE"
        populate_ml2_config /$Q_PLUGIN_CONF_FILE ovn ovn_sb_connection="$OVN_SB_REMOTE"
        populate_ml2_config /$Q_PLUGIN_CONF_FILE ovn neutron_sync_mode="$OVN_NEUTRON_SYNC_MODE"
        populate_ml2_config /$Q_PLUGIN_CONF_FILE ovn ovn_l3_scheduler="$OVN_L3_SCHEDULER"
        populate_ml2_config /$Q_PLUGIN_CONF_FILE securitygroup enable_security_group="$Q_USE_SECGROUP"
        inicomment /$Q_PLUGIN_CONF_FILE securitygroup firewall_driver

        if is_service_enabled neutron-ovn-metadata-agent; then
            populate_ml2_config /$Q_PLUGIN_CONF_FILE ovn ovn_metadata_enabled=True
        else
            populate_ml2_config /$Q_PLUGIN_CONF_FILE ovn ovn_metadata_enabled=False
        fi

        if is_service_enabled q-dns neutron-dns ; then
            iniset $NEUTRON_CONF DEFAULT dns_domain openstackgate.local
            populate_ml2_config /$Q_PLUGIN_CONF_FILE ovn dns_servers="$OVN_DNS_SERVERS"
        fi
    fi

    if is_service_enabled q-dhcp neutron-dhcp ; then
        iniset $NEUTRON_CONF DEFAULT dhcp_agent_notification True
    else
        iniset $NEUTRON_CONF DEFAULT dhcp_agent_notification False
    fi

    if is_service_enabled n-api-meta ; then
        if is_service_enabled neutron-ovn-metadata-agent ; then
            iniset $NOVA_CONF neutron service_metadata_proxy True
        fi
    fi
}

function configure_ovn {
    echo "Configuring OVN"

    if [ -z "$OVN_UUID" ] ; then
        if [ -f ./ovn-uuid ] ; then
            OVN_UUID=$(cat ovn-uuid)
        else
            OVN_UUID=$(uuidgen)
            echo $OVN_UUID > ovn-uuid
        fi
    fi

    # Metadata
    if is_service_enabled neutron-ovn-metadata-agent && is_service_enabled ovn-controller; then
        sudo install -d -o $STACK_USER $NEUTRON_CONF_DIR

        mkdir -p $NEUTRON_DIR/etc/neutron/plugins/ml2
        (cd $NEUTRON_DIR && exec ./tools/generate_config_file_samples.sh)

        cp $NEUTRON_DIR/etc/neutron_ovn_metadata_agent.ini.sample $OVN_META_CONF
        configure_root_helper_options $OVN_META_CONF

        iniset $OVN_META_CONF DEFAULT debug $ENABLE_DEBUG_LOG_LEVEL
        iniset $OVN_META_CONF DEFAULT nova_metadata_host $OVN_META_DATA_HOST
        iniset $OVN_META_CONF DEFAULT metadata_workers $API_WORKERS
        iniset $OVN_META_CONF DEFAULT state_path $NEUTRON_STATE_PATH
        iniset $OVN_META_CONF ovs ovsdb_connection unix:$OVS_RUNDIR/db.sock
        iniset $OVN_META_CONF ovn ovn_sb_connection $OVN_SB_REMOTE
    fi
}

function init_ovn {
    # clean up from previous (possibly aborted) runs
    # create required data files

    # Assumption: this is a dedicated test system and there is nothing important
    # in the ovn, ovn-nb, or ovs databases.  We're going to trash them and
    # create new ones on each devstack run.

    _disable_libvirt_apparmor

    mkdir -p $OVN_DATADIR
    mkdir -p $OVS_DATADIR

    rm -f $OVS_DATADIR/*.db
    rm -f $OVS_DATADIR/.*.db.~lock~
    rm -f $OVN_DATADIR/*.db
    rm -f $OVN_DATADIR/.*.db.~lock~
}

function _start_ovs {
    echo "Starting OVS"
    if is_service_enabled ovn-controller || is_service_enabled ovn-controller-vtep ; then
        # ovsdb-server and ovs-vswitchd are used privately in OVN as openvswitch service names.
        enable_service ovsdb-server
        enable_service ovs-vswitchd

        if [ ! -f $OVS_DATADIR/conf.db ]; then
            ovsdb-tool create $OVS_DATADIR/conf.db $OVS_SHAREDIR/vswitch.ovsschema
        fi

        if is_service_enabled ovn-controller-vtep; then
            if [ ! -f $OVS_DATADIR/vtep.db ]; then
                ovsdb-tool create $OVS_DATADIR/vtep.db $OVS_SHAREDIR/vtep.ovsschema
            fi
        fi

        local dbcmd="$OVS_SBINDIR/ovsdb-server --remote=punix:$OVS_RUNDIR/db.sock --remote=ptcp:6640:$OVSDB_SERVER_LOCAL_HOST --pidfile --detach --log-file"
        dbcmd+=" --remote=db:Open_vSwitch,Open_vSwitch,manager_options"
        if is_service_enabled ovn-controller-vtep; then
            dbcmd+=" --remote=db:hardware_vtep,Global,managers $OVS_DATADIR/vtep.db"
        fi
        dbcmd+=" $OVS_DATADIR/conf.db"
        _run_process ovsdb-server "$dbcmd"

        echo "Configuring OVSDB"
        ovs-vsctl --no-wait set open_vswitch . system-type="devstack"
        ovs-vsctl --no-wait set open_vswitch . external-ids:system-id="$OVN_UUID"
        ovs-vsctl --no-wait set open_vswitch . external-ids:ovn-remote="$OVN_SB_REMOTE"
        ovs-vsctl --no-wait set open_vswitch . external-ids:ovn-bridge="br-int"
        ovs-vsctl --no-wait set open_vswitch . external-ids:ovn-encap-type="geneve"
        ovs-vsctl --no-wait set open_vswitch . external-ids:ovn-encap-ip="$HOST_IP"
        # Select this chassis to host gateway routers
        if [[ "$ENABLE_CHASSIS_AS_GW" == "True" ]]; then
            ovs-vsctl --no-wait set open_vswitch . external-ids:ovn-cms-options="enable-chassis-as-gw"
        fi

        ovn_base_setup_bridge br-int
        ovs-vsctl --no-wait set bridge br-int fail-mode=secure other-config:disable-in-band=true

        local ovscmd="$OVS_SBINDIR/ovs-vswitchd --log-file --pidfile --detach"
        _run_process ovs-vswitchd "$ovscmd" "" "$STACK_GROUP" "root"

        if is_provider_network || [[ $Q_USE_PROVIDERNET_FOR_PUBLIC == "True" ]]; then
            ovn_base_setup_bridge $OVS_PHYSICAL_BRIDGE
            ovs-vsctl set open . external-ids:ovn-bridge-mappings=${PHYSICAL_NETWORK}:${OVS_PHYSICAL_BRIDGE}
        fi

        if is_service_enabled ovn-controller-vtep ; then
            ovn_base_setup_bridge br-v
            vtep-ctl add-ps br-v
            vtep-ctl set Physical_Switch br-v tunnel_ips=$HOST_IP

            enable_service ovs-vtep
            local vtepcmd="$OVS_SCRIPTDIR/ovs-vtep --log-file --pidfile --detach br-v"
            _run_process ovs-vtep "$vtepcmd" "" "$STACK_GROUP" "root"

            vtep-ctl set-manager tcp:$HOST_IP:6640
        fi
    fi

    cd $_pwd
}

function _start_ovn_services {
    _start_process "devstack@ovsdb-server.service"
    _start_process "devstack@ovs-vswitchd.service"

    if is_service_enabled ovs-vtep ; then
        _start_process "devstack@ovs-vtep.service"
    fi
    if is_service_enabled ovn-northd ; then
        _start_process "devstack@ovn-northd.service"
    fi
    if is_service_enabled ovn-controller ; then
        _start_process "devstack@ovn-controller.service"
    fi
    if is_service_enabled ovn-controller-vtep ; then
        _start_process "devstack@ovn-controller-vtep.service"
    fi
    if is_service_enabled neutron-ovn-metadata-agent; then
        _start_process "devstack@neutron-ovn-metadata-agent.service"
    fi
}

# start_ovn() - Start running processes, including screen
function start_ovn {
    echo "Starting OVN"

    _start_ovs

    local SCRIPTDIR=$OVN_SCRIPTDIR
    if ! use_new_ovn_repository; then
        SCRIPTDIR=$OVS_SCRIPTDIR
    fi

    if is_service_enabled ovn-northd ; then
        local cmd="/bin/bash $SCRIPTDIR/ovn-ctl --no-monitor start_northd"
        local stop_cmd="/bin/bash $SCRIPTDIR/ovn-ctl stop_northd"

        _run_process ovn-northd "$cmd" "$stop_cmd"
        ovn-nbctl --db=unix:$OVS_RUNDIR/ovnnb_db.sock set-connection ptcp:6641:$SERVICE_LISTEN_ADDRESS -- set connection . inactivity_probe=60000
        ovn-sbctl --db=unix:$OVS_RUNDIR/ovnsb_db.sock set-connection ptcp:6642:$SERVICE_LISTEN_ADDRESS -- set connection . inactivity_probe=60000
        sudo ovs-appctl -t $OVS_RUNDIR/ovnnb_db.ctl vlog/set console:off syslog:$OVN_DBS_LOG_LEVEL file:$OVN_DBS_LOG_LEVEL
        sudo ovs-appctl -t $OVS_RUNDIR/ovnsb_db.ctl vlog/set console:off syslog:$OVN_DBS_LOG_LEVEL file:$OVN_DBS_LOG_LEVEL
    fi

    if is_service_enabled ovn-controller ; then
        local cmd="/bin/bash $SCRIPTDIR/ovn-ctl --no-monitor start_controller"
        local stop_cmd="/bin/bash $SCRIPTDIR/ovn-ctl stop_controller"

        _run_process ovn-controller "$cmd" "$stop_cmd" "$STACK_GROUP" "root"
    fi

    if is_service_enabled ovn-controller-vtep ; then
        local cmd="$OVS_BINDIR/ovn-controller-vtep --log-file --pidfile --detach --ovnsb-db=$OVN_SB_REMOTE"

        _run_process ovn-controller-vtep "$cmd" "" "$STACK_GROUP" "root"
    fi

    if is_service_enabled neutron-ovn-metadata-agent; then
        run_process neutron-ovn-metadata-agent "$NEUTRON_OVN_BIN_DIR/$NEUTRON_OVN_METADATA_BINARY --config-file $OVN_META_CONF"
        # Format logging
        setup_logging $OVN_META_CONF
    fi

    if is_service_enabled br-ex-tcpdump ; then
        # tcpdump monitor on br-ex for ARP, reverse ARP and ICMP v4 / v6 packets
        sudo ip link set dev $PUBLIC_BRIDGE up
        run_process br-ex-tcpdump "/usr/sbin/tcpdump -i $PUBLIC_BRIDGE arp or rarp or icmp or icmp6 -enlX" "$STACK_GROUP" root
    fi

    if is_service_enabled br-int-flows ; then
        run_process br-int-flows "/bin/sh -c \"set +e; while true; do echo ovs-ofctl dump-flows br-int; ovs-ofctl dump-flows br-int ; sleep 30; done; \"" "$STACK_GROUP" root
    fi

    # NOTE(lucasagomes): To keep things simpler, let's reuse the same
    # RUNDIR for both OVS and OVN. This way we avoid having to specify the
    # --db option in the ovn-{n,s}bctl commands while playing with DevStack
    if use_new_ovn_repository; then
        sudo ln -s $OVS_RUNDIR $OVN_RUNDIR
    fi

    _start_ovn_services
}

function _stop_ovs_dp {
    sudo ovs-dpctl dump-dps | sudo xargs -n1 ovs-dpctl del-dp
    is_kernel_module_loaded vport_geneve && sudo rmmod vport_geneve
    is_kernel_module_loaded vport_vxlan && sudo rmmod vport_vxlan
    is_kernel_module_loaded openvswitch && sudo rmmod openvswitch
}

function stop_ovn {
    if is_service_enabled neutron-ovn-metadata-agent; then
        sudo pkill -9 -f haproxy || :
        stop_process neutron-ovn-metadata-agent
    fi
    if is_service_enabled ovn-controller-vtep ; then
        stop_process ovn-controller-vtep
    fi
    if is_service_enabled ovn-controller ; then
        stop_process ovn-controller
    fi
    if is_service_enabled ovn-northd ; then
        stop_process ovn-northd
    fi
    if is_service_enabled ovs-vtep ; then
        stop_process ovs-vtep
    fi

    stop_process ovs-vswitchd
    stop_process ovsdb-server

    _stop_ovs_dp
}

function _cleanup {
    local path=${1:-$DEST/$OVN_REPO_NAME}
    pushd $path
    cd $path
    sudo make uninstall
    sudo make distclean
    popd
}

# cleanup_ovn() - Remove residual data files, anything left over from previous
# runs that a clean run would need to clean up
function cleanup_ovn {
    local ovn_path=$DEST/$OVN_REPO_NAME
    local ovs_path=$DEST/$OVS_REPO_NAME

    if [ -d $ovn_path ]; then
        _cleanup $ovn_path
    fi

    if [ -d $ovs_path ]; then
        _cleanup $ovs_path
    fi

    sudo rm -f $OVN_RUNDIR
}