I have two Linux routers (RHEL 7) participating in a redundant VRRP configuration provided by the keepalived package version 2.0.20. These two routers used to be running RHEL 6 and keepalived version 2.0.16 but we recently upgraded them to the aforemented versions.
Before we upgraded I had a script that I could run on the backup router that would cause the router to take over as the master router. The script would glean the priority value of the current master router and then increment its own priority to be 1 higher and then restart the keepalived service. This would cause the backup router to take over as the master.
The script would glean the value of the current master router by issuing the following commands:
kill -s $(keepalived --signum=DATA) $(cat /var/run/keepalived.pid)
vrrpPriority='more /tmp/keepalived.data | grep -m1 "Master priority" | awk '{print $4}''
Now that we've upgraded, it doesn't look like the first command does anything anymore. The command appears to execute without errors, but I never get a generated file in /tmp/keepalived.data. So the second command fails since that file doesn't exist.
Is there a better or different way of gleaning the priority value of the current master router?
Another difference is that when we were running in RHEL 6, keepalived was running as an upstart script whereas today keepalived is running as a systemd service. All other aspect of keepalived appear to be working correctly.
Best Answer
I've been able to get this working. In the process of troubleshooting I discovered that selinux was preventing Keepalived from dumping its state to the /tmp directory. After working through the selinux issues and creating the needed selinux policy it started working as expected.