YUM/DNF Training — RHEL/CentOS/Rocky Linux Package Management for DevOps

What Is YUM/DNF?

YUM (Yellowdog Updater Modified) and its successor DNF (Dandified YUM) are the standard package management systems for RHEL, CentOS, Rocky Linux, AlmaLinux, and Fedora. They handle package installation, upgrade, removal, dependency resolution, and repository management. DNF replaced YUM as the default in RHEL 8+ and Fedora, offering better performance, a cleaner API, and improved dependency solving — though the command-line interface remains largely compatible.

Role in DevOps & Infrastructure Automation

YUM/DNF is fundamental to RHEL-family infrastructure automation. Ansible's yum and dnf modules, Packer's provisioners, Dockerfiles, and Kickstart automated installations all depend on YUM/DNF. Managing repositories — adding EPEL, Remi, custom enterprise repos, configuring GPG verification, and version-locking packages — is essential for RHEL-based infrastructure. Understanding YUM/DNF deeply enables faster, more reliable, and more secure infrastructure automation.

Who Should Attend

• DevOps engineers automating RHEL-family Linux infrastructure
• System administrators managing RHEL/CentOS/Rocky server fleets
• Build/release engineers managing YUM repositories for internal distribution

Learning Outcomes

• Master YUM/DNF commands — install, remove, update, search, info, history, groupinstall
• Configure YUM repositories — .repo files, GPG keys, EPEL, custom enterprise repos
• Implement version locking with versionlock plugin to prevent unintended upgrades
• Understand YUM to DNF migration and differences
• Automate YUM/DNF with Ansible for infrastructure-as-code
• Host YUM repositories in Nexus or Artifactory for internal distribution

Course Modules

1. YUM/DNF Fundamentals — Package lifecycle. yum vs. dnf. RPM backend. Repository structure. Metadata.
2. Repository Management — .repo files. GPG keys. EPEL, Remi, custom repos. Repository priorities.
3. Package Operations — Dependency resolution. Version locking. History and rollback. Module streams (DNF).
4. YUM/DNF in Automation — Ansible yum/dnf modules. Packer. Dockerfile. Kickstart %packages.
5. Enterprise YUM Management — Hosting repos in Nexus/Artifactory. createrepo. GPG signing. Compliance.
6. Capstone: Enterprise Package Management — Build a complete package management workflow for a RHEL server fleet.

Hands-on Labs (8 total)

Configure custom YUM repositories. Implement version locking for production servers. Set up EPEL and manage priorities. Write Ansible playbooks with yum/dnf module. Host a custom YUM repo in Nexus and install from it.

Related Courses

See APT Training, RPM Training, SysOps Training, and Ansible Training.