First, Thank you for this tutorial which helped me a lot.
I have implemented the same architecture using 2 redhat7 servers.
When testing keepalived service crash; the failover to slave server works fine, the VIP is assigned the slave server which is then declared as newly primary server.
That is not the case when crashing Haproxy service. Failover procedure is not triggered and users requests are still routed to the primary server, which is obviously not responding.
I think vrrp_script is not working correctly on redhat 7 as killall command does not exist in this version. Is there any other alternatives i can use ?