DNF Package Manager¶
DNF is the default package manager for RHEL, Fedora, and CentOS Stream. Understanding its repository management, dependency resolution, and transaction history is critical for maintaining reproducible server builds and debugging "package not found" issues in production.
Why this matters¶
Package management is the foundation of server provisioning and patching. A misconfigured repo or an unintended module stream switch can break an entire fleet during a routine update. DNF's transaction history and rollback capabilities are your safety net.
Prerequisites¶
Basic Linux command-line familiarity and an understanding of how software packaging works (RPMs, dependencies).
Key concepts covered¶
- Repository configuration: baseurl, metalink, GPG keys, and priority
- Module streams: choosing between multiple versions of the same software
- Transaction history: undo, rollback, and replay for safe patching
- Version locking:
versionlockplugin for pinning critical packages
Contents¶
Start with the primer for core concepts, then move to street-level operations and common pitfalls.
| # | File | What it covers |
|---|---|---|
| 1 | Primer | Repos, modules, dependency resolution, and how DNF differs from yum |
| 2 | Street Ops | Day-to-day commands — installing, downgrading, pinning, and auditing packages |
| 3 | Footguns & Pitfalls | Broken repos, module stream conflicts, and transaction rollback gotchas |