How to set up your CentOS repository

Creating a local yum repository on CentOS 7 from an ISO image is a convenient way to provide your local network with a comprehensive set of software packages. By creating a local repository from an ISO, you can have all the packages available on the installation media at your fingertips and eliminate the need to access remote repositories every time you need to install or update software on your CentOS 7 machines.

To create a local yum repository on CentOS 7 from an ISO image, you’ll first need to mount the ISO file on your system. You can do this by using the mount command and specifying the path to the ISO file.

Once the ISO is mounted, you can use the createrepo command to create a repository from the contents of the ISO. The createrepo command will scan the contents of the mounted ISO file and generate a repository metadata file that contains information about the packages and their dependencies.

After creating the repository metadata, you’ll need to configure your web server to serve the repository files. You can do this by creating a virtual host in Apache or Nginx and pointing it to the directory where the repository files are stored.

Finally, you’ll need to configure your CentOS 7 machines to use the local repository instead of the remote repositories they normally use. You can do this by editing the yum configuration file to point to the URL of your local repository.

With your local repository set up from an ISO image, you’ll be able to install and update software on your CentOS 7 machines much more quickly and efficiently. By having all the necessary packages available locally, you can save time and bandwidth and ensure that your systems have access to the software they need at all times.

You may need your own repository if you use a secure network segment, want to reduce package download time, use your own builds for installation packages. Installation and configuration will be done from the command line.

Server preparation

Perform some server security settings.

Firewall

We allow ports on which our server will accept requests:

firewall-cmd --permanent --add-port={80,443}/tcp
firewall-cmd --reload

Disable SELinux

setenforce 0
sed -i 's/^SELINUX=.*/SELINUX=disabled/g' /etc/selinux/config

Web server setup

The repository for downloading and installing packages is a repository of files accessed via the http protocol. To do this, we need to deploy a web server.

As the last one, we will use nginx. To install it, install the epel repository:

yum install epel-release

After we install nginx itself:

yum install nginx

Enable start the web server:

systemctl enable ngin

Run it:

systemctl start nginx

Open the browser and go to http://<server IP address> – we should see the NGINX greeting:

Creating a repository

Let’s set up our repository, which will store the installation packages. We will also configure their automatic synchronization with the CentOS repository.

Install the necessary utilities to work with the local repository:

yum install createrepo yum-utils

Create directories for the repository:

mkdir -p /usr/share/nginx/html/repos/7/{os,updates}/x86_64

Synchronizing our future repository with the package source

rsync -iavrt --delete --exclude='repo*' rsync://mirror.yandex.ru/centos/7/os/x86_64/ /usr/share/nginx/html/repos/7/os/x86_64/

rsync -iavrt --delete --exclude='repo*' rsync://mirror.yandex.ru/centos/7/updates/x86_64/ /usr/share/nginx/html/repos/7/updates/x86_64/

Create repositories:

createrepo -v /usr/share/nginx/html/repos/7/os/x86_64

createrepo -v /usr/share/nginx/html/repos/7/updates/x86_64

We also allow groups:

createrepo /usr/share/nginx/html/repos/7/os/x86_64 -g /usr/share/nginx/html/repos/7/os/x86_64/repodata/repomd.xml

createrepo /usr/share/nginx/html/repos/7/updates/x86_64 -g /usr/share/nginx/html/repos/updates/os/x86_64/repodata/repomd.xml

Set up nginx:

vi /etc/nginx/conf.d/default.conf

...
    location / {
        root   /usr/share/nginx/html;
        index  index.html index.htm;
        autoindex on;
    }
    ...

Restart nginx:

systemctl restart nginx

We open the browser and go to http://<server IP address>/repos/7 – we should see a list of os and updates. Walking through it, we will find a list of downloaded packages.

Client setup.

To ensure that all packages will be downloaded from the local repository, disable the existing ones:

find /etc/yum.repos.d -type f -exec sed -i "s/enabled=1/enabled=0/g" {} \\;

Create a file with the repository settings:

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

[local]
name=Local Yum Repo
baseurl=http://192.168.40.10/repos/$releasever/os/$basearch/
enabled=1
gpgcheck=0

[local-update]
name=Local Yum Repo for update packages
baseurl=http://192.168.40.10/repos/$releasever/updates/$basearch/
enabled=1
gpgcheck=0

You can also set a priority for each of the repositories:

Complete. You can install.

In the video below you can practice how to create local repository from ISO image: