YumRepo Error: All mirror URLs are not using ftp, http[s] or file.

YumRepo Error: All mirror URLs are not using ftp, http[s] or file.
 Eg. Invalid release/
removing mirrorlist with no valid mirrors: /var/cache/yum/x86_64/6Server/base/mirrorlist.txt

Solution:

1. Check the release.

[root@cobtest yum.repos.d]# ls -la  /etc/*release*
-rw-r--r--. 1 root root 55 Jun 12  2015 /etc/redhat-release
lrwxrwxrwx. 1 root root 14 Jul 14 10:01 /etc/system-release -> redhat-release
-rw-r--r--  1 root root 49 Jun 12  2015 /etc/system-release-cpe
[root@cobtest yum.repos.d]# cat /etc/redhat-release
Red Hat Enterprise Linux Server release 6.7 (Santiago)
[root@cobtest yum.repos.d]# cat /etc/system-release-cpe
cpe:/o:redhat:enterprise_linux:6server:ga:server
[root@cobtest yum.repos.d]#

2. Edit the  CentOS Base repo.

vi CentOS-Base.repo

3. Replace "$releasever" with 6.

[base]
name=CentOS-6 - Base
mirrorlist=http://mirrorlist.centos.org/?release=6&arch=$basearch&repo=os&infra=$infra
#baseurl=http://mirror.centos.org/centos/6/os/$basearch/
gpgcheck=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-6

4. Now do a " yum repolist"