Multi-Master VRRP set-up

Weekly sharing

Hi everyone, I am Ekim, a fresh Bootcamp graduate and an IT helper (I don't dare to call myself a programmer yet). Every Friday, I will share some of the work that I've done over the last week in a bid to get feedbacks from you guys and record my journey to become a programmer.

Introduction

In the last week sharing, I revealed that I had failed to make my VRRP working. Fortunately, that was fixed and is running successfully now. One thing I noticed was that most resources online only taught people how to make master-backup VRRP instead of master-master. Today, I would like to share my configurations of Keepalived for master-master usage.

Previously

Installation and configurations of keepalived

Machine one

sudo apt-get install keepalived
cd /etc/keepalived
vim keepalived.conf

# ----- vim keepalived.conf -----
vrrp_instance machineOne {
        state MASTER
        nopreempt                   # preempt = get back the master position when recovers, nopreempt = stay in backup position when recovers (dual-master setting)
        interface eno1              # interface
        virtual_router_id 101
        priority 101                # same priority to make sure both machines are master
        advert_int 1                # interval between advertisements
        authentication {
                auth_type PASS
                auth_pass abcdefg
        }
        virtual_ipaddress {         # virtual IP 
                192.168.29.11
        }
}
# ----- vim keepalived.conf -----

Machine two

sudo apt-get install keepalived
cd /etc/keepalived
vim keepalived.conf

# ----- vim keepalived.conf -----
vrrp_instance esl35 {
        state MASTER
        nopreempt
        interface eno1
        virtual_router_id 101
        priority 101
        advert_int 1
        authentication {
                auth_type PASS
                auth_pass abcdefg
        }
        virtual_ipaddress {
                192.168.29.11
        }
}
# ----- vim keepalived.conf -----

SSH key integration

Before starting the keepalived service, we need to make sure that the SSH key files are the two machines are the same if master-master VRRP approach is adopted. This will avoid conflicts between machines.

# In any one of the machine
# e.g. 192.168.29.10
cd /etc/ssh
ls 

# ----- ls -----
#moduli        sshd_config       ssh_host_dsa_key.pub    ssh_host_ed25519_key      ssh_host_rsa_key.pub
#ssh_config    sshd_config.d     ssh_host_ecdsa_key      ssh_host_ed25519_key.pub  ssh_import_id
#ssh_config.d  ssh_host_dsa_key  ssh_host_ecdsa_key.pub  ssh_host_rsa_key
# ----- ls -----

# syncing all those files to another machine
# account@server-ip should be like [email protected]
rsync ./* < account@server-ip >:/etc/ssh

Conclusion

I hope you enjoy my sharing so far. I am not sure if I could keep writing and sharing every week. I aimed to make the VRRP working through rVRRPd, but I could not find sufficient resources that could help me set that up successfully. If you do know how to make it working, please comment below no matter how ancient this sharing has become.