CentOS

[root@localhost yum]# ls -la /etc/yum.repos.d/
total 60
drwxr-xr-x.  2 root root  270 Feb 23 00:01 .
drwxr-xr-x. 97 root root 8192 Feb 24 02:33 ..
-rw-r--r--.  1 root root 1664 Nov 23 08:16 CentOS-Base.repo
-rw-r--r--.  1 root root 1309 Nov 23 08:16 CentOS-CR.repo
-rw-r--r--.  1 root root  649 Nov 23 08:16 CentOS-Debuginfo.repo
-rw-r--r--.  1 root root  314 Nov 23 08:16 CentOS-fasttrack.repo
-rw-r--r--.  1 root root  630 Nov 23 08:16 CentOS-Media.repo
-rw-r--r--.  1 root root 1331 Nov 23 08:16 CentOS-Sources.repo
-rw-r--r--.  1 root root 5701 Nov 23 08:16 CentOS-Vault.repo
-rw-r--r--.  1 root root 2424 Dec 31 00:40 docker-ce.repo
-rw-r--r--.  1 root root  951 Oct  2  2017 epel.repo
-rw-r--r--.  1 root root 1050 Oct  2  2017 epel-testing.repo
-rw-r--r--.  1 root root  410 Oct  2 03:34 zabbix.repo

mount -t iso9660 /dev/sr0 /mnt

vim /etc/yum.repos.d/local.repo

[local]
name=local
baseurl=file:///mnt
enabled=1
gpgcheck=0

yum clean all

yum makecache

wget -o /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-7.repo

wget -o /etc/yum.repos.d/CentOS7-Base-163.repo http://mirrors.163.com/.help/CentOS-Base-163.repo

yum -y install yum-plugin-priorities

[root@localhost yum]# cat /etc/yum/pluginconf.d/priorities.conf
[main]
enabled = 1

vim /etc/yum.repos.d/local.repo

[local]
name=local
baseurl=file:///mnt
enabled=1
gpgcheck=0
priorities=1