Managing Packages with DNF

Installing Packages with dnf install

The most common task you'll perform is installing new software. The command is straightforward, but its power lies in how dnf automatically handles dependencies—the other pieces of software your chosen package needs to function.

The basic syntax is:
sudo dnf install <package_name>

Let's watch a quick demonstration.

As you saw, dnf provides a summary of the transaction:

• The package(s) you requested to install.
• The additional dependency packages that will be installed.
• The total download size and the disk space required.
• A confirmation prompt Is this ok [y/N]:.

You can also install multiple packages at once by listing them all in the same command. This is more efficient than running the command repeatedly.

sudo dnf install <package1> <package2> <package3>

Automating Confirmation with -y

You'll often see the -y flag used with dnf commands, which automatically answers "yes" to any confirmation prompts.

sudo dnf install -y <package_name>

This is very useful for automation and scripting, where you can't manually type 'y'. However, for interactive use, it's good practice to omit -y so you have a chance to review the changes before they happen. A typo could lead to installing or removing the wrong packages!

Updating Packages with dnf upgrade

Keeping your system updated is critical for security and stability. dnf makes this process simple. You can update a single package or the entire system.

1. Check for available updates: Before running an upgrade, you can see what new packages are available.
   dnf check-update

2. Upgrade a specific package:
   sudo dnf upgrade <package_name>

3. Upgrade all packages on the system: This is the command you'll run regularly to keep your system current.
   sudo dnf upgrade

Let's see this in action.

Note: The command dnf update is an alias for dnf upgrade and does the same thing. You will often see both used interchangeably in documentation online.

Removing Packages with dnf remove

When you no longer need a piece of software, you can remove it using dnf remove. One of its best features is that it also identifies and offers to remove dependencies that are no longer needed by any other package, helping to keep your system clean.

The syntax is:
sudo dnf remove <package_name>

Here is a static image showing the removal of multiple packages and their dependencies. This is exactly the kind of output you should review before typing 'y'.

Cleaning Up Orphaned Dependencies

Sometimes, dependencies might be left behind. You can run a dedicated command to find and remove any packages that were installed as dependencies but are no longer required by any installed program.

sudo dnf autoremove

It's good practice to run this occasionally to free up disk space and reduce clutter.

For a quick reference of all the commands we've discussed today, the official Fedora documentation is an excellent resource.

Your Turn: Hands-on Practice

Time to put theory into practice. Open your terminal on your Fedora system and work through these exercises. This is the most important part of the lesson!

• Exercise 1: Install a Web Server
  In the last lesson, you found the nginx package. Now, install it. After the installation, verify that it's present on your system using a command from the previous lesson.

  Solution

  
  
  
  # 1. Install nginx
  sudo dnf install nginx
  
  
  
  
  # 2. Verify the installation
  dnf list installed nginx
  

  You should see the nginx package listed in the output of the second command.

• Exercise 2: Install Multiple Tools at Once
  htop is a popular interactive process viewer, and neofetch is a command-line tool that displays system information in an aesthetic way. Install both of them with a single command.

  Solution

  
  
  
  # Install both packages
  sudo dnf install htop neofetch
  

  After installation, you can try running htop or neofetch in your terminal to see them work. Press q to exit htop.

• Exercise 3: Update Your System
  First, check to see which of your installed packages have updates available. Then, run a full system upgrade. Note: This may download a significant amount of data and take some time, especially on a new installation.

  Solution

  
  
  
  # 1. Check for available updates
  dnf check-update
  
  
  
  
  # 2. Perform the full system upgrade
  sudo dnf upgrade
  

  Review the list of packages to be upgraded and press y to proceed.

• Exercise 4: Remove a Package
  Let's say you've decided you don't need neofetch anymore. Remove it from your system.

  Solution

  
  
  
  # Remove the neofetch package
  sudo dnf remove neofetch
  

  Confirm the removal when prompted.

• Exercise 5: Clean Up
  Run the autoremove command to see if removing neofetch (or any other package) left behind any orphaned dependencies that can be cleaned up.

  Solution

  
  
  
  # Check for and remove orphaned dependencies
  sudo dnf autoremove
  

  If there are any packages to be removed, DNF will list them and ask for confirmation.

Conclusion

Great job! You have now mastered the fundamental cycle of package management on Fedora: installing, updating, and removing software. These skills are the bedrock of system administration and are essential for setting up and maintaining any development environment.

Key Takeaways:

• sudo dnf install <package>: Installs software and its dependencies.
• sudo dnf upgrade: Updates all packages on your system to their latest versions, which is crucial for security.
• sudo dnf remove <package>: Uninstalls software and can also remove its unused dependencies.
• sudo dnf autoremove: A housekeeping command to clean up any leftover dependencies.
• Always review the transaction summary before confirming a change, especially when removing packages.

So far, we have only used the default software sources (repositories) that come with Fedora. But what if the software you need isn't available there? In our next lesson, we will address this by learning how to list, enable, disable, and add new DNF repositories, giving you access to an even wider world of software.