Keepalived and libvirt MACVTAP network interfaces

Wed, 13 Jan 2021 00:00:00 +0000

Keepalived is a routing software written in C that can be used to setup load balancing and high availiability for Linux machines.

NOTE: hypervisor is Debian 10 (Buster) with libvirt and qemu/kvm, virtual machines also are Debian 10 (Buster).

Keepalived configuration

Install keepalived:

$ apt install keepalived

Install nginx, it will be use to check that keepalived is actually working:

$ apt install nginx
$ systemctl enable --now nginx

Configure keepalived:

$ vi /etc/keepalived/keepalived.conf
---
global_defs {
 enable_script_security # prevents tampering with the check script
 script_user root # defines which user runs the check script
}

vrrp_script chk_nginx {
 script "/opt/scripts/nginx-check.sh"
 interval 2 # run script every 2 seconds
 weight 2 # add 2 points if OK
}

vrrp_instance VI_1 {
 interface enp2s0 # interface to monitor
 virtual_router_id 51
 priority 101 # MASTER 101, BACKUP 100
 advert_int 1
 nopreempt # comment to not have the VIP go back to MASTER 
 # -> when it comes back online
 authentication {
 auth_type PASS
 auth_pass myPass # maximum 8 chars
 }
 virtual_ipaddress {
 10.10.0.12/24 # VIP (Virtual IP Address)
 }
 track_script {
 chk_nginx
 }
}

Also add a script to check if nginx is alive and well:

High Availiability on nagg.eu

Keepalived and libvirt MACVTAP network interfaces

Keepalived configuration