network: Add BGP+EVPN+VXLAN script to main repository and Agent package (#9778)

This script can be used to use BGP+EVPN for VXLAN instead of multicast.

In order to use the script operators need to manually create a symlink:

cd /usr/share
ln -s modifyvxlan.sh cloudstack-common/scripts/vm/network/vnet/modifyvxlan-evpn.sh

Configuring BGP and EVPN is outside of the scope of CloudStack and is
up to the operator to configure.

This commit just adds this script to the main repository and does not
change any existing functionality.
This commit is contained in:
Wido den Hollander 2025-01-13 15:38:11 +01:00 committed by GitHub
parent bd874eaa44
commit baad8ddc91
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#!/usr/bin/env bash
# Licensed to the Apache Software Foundation (ASF) under one
# or more contributor license agreements. See the NOTICE file
# distributed with this work for additional information
# regarding copyright ownership. The ASF licenses this file
# to you 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.
#
# Use BGP+EVPN for VXLAN with CloudStack instead of Multicast
#
# The default 'modifyvxlan.sh' script from CloudStack uses Multicast instead of EVPN for VXLAN
# In order to use this script and thus utilize BGP+EVPN, symlink this file:
#
# cd /usr/share
# ln -s cloudstack-common/scripts/vm/network/vnet/modifyvxlan-evpn.sh modifyvxlan.sh
#
#
# CloudStack will not handle the BGP configuration nor communication, the operator of the hypervisor will
# need to configure the properly.
#
# Frrouting is recommend to be used on the hypervisor to establish BGP sessions with upstream routers and
# exchange BGP+EVPN information.
#
# More information about BGP and EVPN with FRR: https://vincent.bernat.ch/en/blog/2017-vxlan-bgp-evpn
#
DSTPORT=4789
# We bind our VXLAN tunnel IP(v4) on Loopback device 'lo'
DEV="lo"
usage() {
echo "Usage: $0: -o <op>(add | delete) -v <vxlan id> -p <pif> -b <bridge name> (-6)"
}
localAddr() {
local FAMILY=$1
if [[ -z "$FAMILY" || $FAMILY == "inet" ]]; then
ip -4 -o addr show scope global dev ${DEV} | awk 'NR==1 {gsub("/[0-9]+", "") ; print $4}'
fi
if [[ "$FAMILY" == "inet6" ]]; then
ip -6 -o addr show scope global dev ${DEV} | awk 'NR==1 {gsub("/[0-9]+", "") ; print $4}'
fi
}
addVxlan() {
local VNI=$1
local PIF=$2
local VXLAN_BR=$3
local FAMILY=$4
local VXLAN_DEV=vxlan${VNI}
local ADDR=$(localAddr ${FAMILY})
echo "local addr for VNI ${VNI} is ${ADDR}"
if [[ ! -d /sys/class/net/${VXLAN_DEV} ]]; then
ip -f ${FAMILY} link add ${VXLAN_DEV} type vxlan id ${VNI} local ${ADDR} dstport ${DSTPORT} nolearning
ip link set ${VXLAN_DEV} up
sysctl -qw net.ipv6.conf.${VXLAN_DEV}.disable_ipv6=1
fi
if [[ ! -d /sys/class/net/$VXLAN_BR ]]; then
ip link add name ${VXLAN_BR} type bridge
ip link set ${VXLAN_BR} up
sysctl -qw net.ipv6.conf.${VXLAN_BR}.disable_ipv6=1
fi
bridge link show|grep ${VXLAN_BR}|awk '{print $2}'|grep "^${VXLAN_DEV}\$" > /dev/null
if [[ $? -gt 0 ]]; then
ip link set ${VXLAN_DEV} master ${VXLAN_BR}
fi
}
deleteVxlan() {
local VNI=$1
local PIF=$2
local VXLAN_BR=$3
local FAMILY=$4
local VXLAN_DEV=vxlan${VNI}
ip link set ${VXLAN_DEV} nomaster
ip link delete ${VXLAN_DEV}
ip link set ${VXLAN_BR} down
ip link delete ${VXLAN_BR} type bridge
}
OP=
VNI=
FAMILY=inet
option=$@
while getopts 'o:v:p:b:6' OPTION
do
case $OPTION in
o) oflag=1
OP="$OPTARG"
;;
v) vflag=1
VNI="$OPTARG"
;;
p) pflag=1
PIF="$OPTARG"
;;
b) bflag=1
BRNAME="$OPTARG"
;;
6)
FAMILY=inet6
;;
?) usage
exit 2
;;
esac
done
if [[ "$oflag$vflag$pflag$bflag" != "1111" ]]; then
usage
exit 2
fi
lsmod|grep ^vxlan >& /dev/null
if [[ $? -gt 0 ]]; then
modprobe=`modprobe vxlan 2>&1`
if [[ $? -gt 0 ]]; then
echo "Failed to load vxlan kernel module: $modprobe"
exit 1
fi
fi
#
# Add a lockfile to prevent this script from running twice on the same host
# this can cause a race condition
#
LOCKFILE=/var/run/cloud/vxlan.lock
(
flock -x -w 10 200 || exit 1
if [[ "$OP" == "add" ]]; then
addVxlan ${VNI} ${PIF} ${BRNAME} ${FAMILY}
if [[ $? -gt 0 ]]; then
exit 1
fi
elif [[ "$OP" == "delete" ]]; then
deleteVxlan ${VNI} ${PIF} ${BRNAME} ${FAMILY}
fi
) 200>${LOCKFILE}