How to Build a Local YUM Repository on CentOS Using Scripts, ISO, Aliyun Mirror, and LAN Sharing

Method 1: Create a Local YUM Repository with a Bash Script

The script first checks whether the CD-ROM is already mounted. If it is, it mounts the disc to /mnt; otherwise it prompts the user to mount the disc and exits with code 2. It then switches to /etc/yum.repos.d/, creates a directory a if it does not exist, moves all Cent* files into it, and generates an a.repo file that points the baseurl to file:///mnt. Finally it runs yum clean all and yum makecache to build the cache, reporting success when the commands return exit code 0.

#!/bin/bash
mount |grep sr0 &> /dev/null
if [ $? -eq 0 ]; then
  mount /dev/cdrom /mnt &> /dev/null
else
  echo "请挂载光盘！"
  exit 2
fi
cd /etc/yum.repos.d/
if [ -e a ]; then
  echo "文件已经存在"
else
  mkdir a
fi
mv Cent* a &> /dev/null
cat << EOR >> a.repo
[base]
name=a
baseurl=file:///mnt
gpgcheck=0
EOR
yum clean all
yum makecache
if [ $? -eq 0 ]; then
  echo "本地yum仓库已经创建完成！"
fi

Method 2: Build a Local YUM Repository by Mounting an ISO Image

Upload the CentOS‑7 ISO (e.g., CentOS-7-x86_64-DVD-1611.iso) to /opt. Create a mount point and mount the ISO:

mkdir /mnt/centos7.5
mount /opt/CentOS-7-x86_64-DVD-1611.iso /mnt/centos7.5

Backup existing repo files:

mv /etc/yum.repos.d/*.repo /etc/yum.repos.d/bak

Create a new repo configuration file CentOS.Base.repo with the following content:

[centos7.5]
name=centos7.5
baseurl=file:///mnt/centos7.5
enabled=1
gpgcheck=0
gpgkey=file:///mnt/centos7.5/RPM-GPG-KEY-CentOS-7

Refresh the cache:

yum clean all
yum repolist

Method 3: Use the Official Aliyun YUM Mirror

Navigate to the repo directory and back up existing .repo files:

cd /etc/yum.repos.d/
mkdir bak
mv *.repo bak

Download the Aliyun base repo and EPEL repo:

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

Verify the files were downloaded:

# ls
a  bak  CentOS-Base.repo  epel.repo

Optionally install a test program (e.g., cowsay) to confirm the repo works:

yum -y install cowsay

Method 4: Share a Local YUM Repository Over a LAN

Install and start the Apache HTTP server on the host that holds the repository:

yum install -y httpd
systemctl start httpd
systemctl stop firewalld

Mount the ISO to a directory served by Apache:

mount /opt/CentOS-7.5-1804.iso /var/www/html/CentOS7.5/

On each client, create a repo file pointing to the host’s IP address:

vim /etc/yum.repos.d/CentOS-Base.repo

[local]
name=net_bendiyum
baseurl=http://192.168.1.8/CentOS7.5/
enabled=1
gpgcheck=0

Refresh the client cache and list available repos:

yum clean all
yum makecache
yum repolist

References

Aliyun official YUM source: https://developer.aliyun.com/article/675241