Package Management

Understanding Package Managers

Package Management Systems

APT (Advanced Package Tool) - Debian/Ubuntu
YUM (Yellowdog Updater Modified) - RHEL/CentOS
DNF (Dandified YUM) - Fedora/RHEL 8+
Zypper - openSUSE

APT Package Manager

Basic APT Commands

apt update              # Update package lists
apt upgrade             # Upgrade installed packages
apt install package    # Install a package
apt remove package     # Remove a package
apt autoremove         # Remove unused dependencies

Advanced APT Usage

apt search keyword     # Search for packages
apt show package       # Show package details
apt list --installed   # List installed packages
apt clean              # Clean package cache

YUM Package Manager

Basic YUM Commands

yum check-update       # Check for updates
yum update             # Update packages
yum install package    # Install a package
yum remove package     # Remove a package
yum autoremove         # Remove unused dependencies

Advanced YUM Usage

yum search keyword     # Search for packages
yum info package       # Show package info
yum list installed     # List installed packages
yum clean all         # Clean cache and metadata

Repository Management

APT Repository Management

# Add repository
add-apt-repository ppa:user/repo-name

# Edit sources
vim /etc/apt/sources.list

# Manage repository keys
apt-key add key.gpg
apt-key del keyid

YUM Repository Management

# Add repository file
vim /etc/yum.repos.d/repo-name.repo

# Import GPG key
rpm --import key.gpg

# List repositories
yum repolist

Package Dependencies

Managing Dependencies

Understanding dependency resolution
Handling conflicts
Broken package fixes

Troubleshooting

# APT
apt --fix-broken install
dpkg --configure -a

# YUM
yum deplist package
yum resolve

Software Installation from Source

Compilation Steps

# Install build tools
apt install build-essential   # Debian/Ubuntu
yum groupinstall "Development Tools"   # RHEL/CentOS

# Basic compilation
./configure
make
make install

Hands-on Practice

Exercise 1: Package Management

Update system:

# Debian/Ubuntu
sudo apt update && sudo apt upgrade
   
# RHEL/CentOS
sudo yum update

Install and remove packages:

# Install package
sudo apt install nginx
   
# Remove package
sudo apt remove nginx

Exercise 2: Repository Management

Add a new repository
Import GPG key
Install software from new repository
Verify installation

Best Practices

System Updates

Regular system updates
Security updates priority
Update scheduling
Backup before major upgrades

Package Management

Verify package authenticity
Keep clean package cache
Document installed packages
Use version control for configs

Additional Resources

Next Steps

Learn about configuration management tools
Explore automated package deployment
Study package building
Understand package security