CONFIGURE_KEEPALIVED.md

How to configure keepalived

1. Install keepalived

apt install keepalived

2. Configure keepalived

Copy the following config to /etc/keepalived/keepalived.conf and change it to fit your needs.

vrrp_instance LB_1 {
    state MASTER
    interface eth0
    virtual_router_id 1
    priority 100

    authentication {
        auth_type PASS
        auth_pass imasupersecurepassword
    }

    # add virtual router id as last argument
    notify "/bin/sudo /opt/hcloud-failover/hcloud_failover.py 1"
}

On the second (and all other servers) change:

• the name of the vrrp instance (LB_1)
• the state (to BACKUP)
• the virtual_router_id to something unique
• the priority to something that matches your needs
• the unicast_src_ip to the ip of the local system
• the unicast_peer array to the ip addresses of all other systems

3. Create a service user

adduser keepalived_script

4. Install and configure sudo

apt install sudo
vim /etc/sudoers.d/90-keepalived

keepalived_script ALL=NOPASSWD: /bin/ip*, /opt/hcloud-failover/hcloud_failover.py*

5. Make sure keepalived is enabled and started

systemctl enable keepalived --now

6. Done

Enjoy :)