Peer cert cannot be verified or peer cert invalid while using yum
If you are getting above error then perform the following to resolve the yum error.
1- check and correct the date and time of the server.
2- Check /etc/hosts file for any false DNS resolutions of servers.
3-Disable SSL verification by adding sslverify=false in /etc/yum.conf
4- Check repo file is using http or https and verify url.