Managing software repositories is a critical task for system administrators working with Red Hat-based Linux distributions like Rocky Linux, Fedora, and RHEL. In this tutorial, we’ll explore how to enable and configure RPM repositories, both manually and using the dnf config-manager tool. We’ll also discuss how to clean up and remove repositories when they are no longer needed.

What Are RPM Repositories?

RPM repositories are collections of RPM (Red Hat Package Manager) files hosted on a server, which can be accessed by the DNF package manager. These repositories contain software packages, updates, and dependencies that your system can install, update, or remove as needed.

Method 1: Manually Creating and Configuring a .repo File

Step 1: Locate the Repositories Directory

The first step in manually configuring a repository is to create a .repo file in the /etc/yum.repos.d/ directory. Each .repo file represents a repository and contains configuration details that tell DNF how to interact with it.

cd /etc/yum.repos.d/

Step 2: Create a New .repo File

Using your preferred text editor, create a new .repo file. For this example, we’ll create a repository file for the Extra Packages for Enterprise Linux (EPEL) repository.

sudo vim epel.repo

Step 3: Define the Repository Configuration

Inside the .repo file, you’ll define the repository configuration. Here’s a example:

[epel]
name=Extra Packages for Enterprise Linux $releasever - $basearch
# It is much more secure to use the metalink, but if you wish to use a local mirror
# place its address here.
#baseurl=https://download.example/pub/epel/$releasever/Everything/$basearch/
metalink=https://mirrors.fedoraproject.org/metalink?repo=epel-$releasever&arch=$basearch&infra=$infra&content=$contentdir
enabled=1
gpgcheck=1
countme=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-EPEL-$releasever

Explanation of Configuration Parameters:

• [epel]: This is the repository ID, which is used by DNF to reference the repository.
• name: A human-readable name for the repository.
• baseurl: The URL where the repository’s RPM packages are hosted. The $basearch variable automatically expands to the architecture of your system (e.g., x86_64).
• enabled: Set to 1 to enable the repository or 0 to disable it.
• gpgcheck: Set to 1 to enable GPG signature verification for packages from this repository.
• gpgkey: The URL of the GPG key used to sign the packages in this repository.

Step 4: Save and Exit

After adding the configuration details, save the .repo file and exit the text editor. Your repository is now configured and ready for use.

Step 5: Verify the Repository Configuration

To ensure that the repository has been configured correctly, you can list all enabled repositories:

[root@server1 devops]# dnf repolist
repo id                                           repo name
appstream                                         Rocky Linux 9 - AppStream
baseos                                            Rocky Linux 9 - BaseOS
epel                                              Extra Packages for Enterprise Linux 9 - x86_64
epel-cisco-openh264                               Extra Packages for Enterprise Linux 9 openh264 (From Cisco) - x86_64
extras                                            Rocky Linux 9 - Extras

This command should show your newly added repository in the list.

Method 2: Using dnf config-manager to Manage Repositories

The dnf config-manager tool simplifies the process of enabling, disabling, and managing repositories without manually editing .repo files.

Step 1: Install dnf-plugins-core Package

Before using dnf config-manager, ensure that the dnf-plugins-core package is installed, as it provides the necessary tools.

sudo dnf install dnf-plugins-core

Step 2: Enable a Repository

To enable a repository using dnf config-manager, use the following command:

sudo dnf config-manager --add-repo=https://mirrors.fedoraproject.org/metalink?repo=epel-$releasever&arch=$basearch&infra=$infra&content=$contentdir

This command automatically creates a .repo file and configures it to use the specified URL.

Step 3: Disable a Repository

If you need to disable a repository, you can do so with the following command:

sudo dnf config-manager --set-disabled <repo name>
sudo dnf config-manager --set-disabled epel

Step 4: Enable a Disabled Repository

To re-enable a disabled repository, simply use the –set-enabled option:

sudo dnf config-manager --set-enabled epel

Step 5: List Enabled Repositories

To list all enabled repositories, use:

dnf repolist

This command shows all currently active repositories, including those enabled via dnf config-manager.

Cleaning Up and Removing Repositories

Step 1: Remove a Repository

To remove a repository, you can delete the corresponding .repo file from /etc/yum.repos.d/:

sudo rm /etc/yum.repos.d/epel.repo

This will remove the EPEL repository from your system.

Step 2: Clean Up DNF Cache

After removing a repository, it’s a good practice to clean up the DNF cache to avoid potential conflicts or outdated metadata:

sudo dnf clean all

This command clears out all cached package data, ensuring that DNF retrieves fresh metadata the next time it accesses a repository.

Managing RPM repositories is a key task for maintaining a stable and secure Red Hat-based Linux environment. Whether you prefer to manually create and configure .repo files or use the dnf config-manager tool for easier management, this tutorial provides you with the knowledge to effectively add, configure, and remove repositories on your system. By understanding how to manage repositories, you can ensure that your system has access to the necessary software packages and updates while maintaining a clean and efficient package management environment.