q26-package-management

Énoncé§

Solve this question on: app-srv1

1. Install the package tree and write its version into /opt/course/26/tree-version.
2. Find which package owns the file /usr/bin/vim and write it into /opt/course/26/owner.
3. List all files installed by the nginx package into /opt/course/26/nginx-files.
4. Put a hold on the openssh-server package so it is not upgraded by apt.

Solution§

The LFCS exam may use either Debian (apt/dpkg) or RHEL (dnf/rpm). Know both.

Debian / Ubuntu — apt + dpkg§

sudo apt update                                # refresh indexes
sudo apt install tree                          # install
sudo apt remove tree                           # remove (keep config)
sudo apt purge tree                            # remove + config
sudo apt upgrade                               # upgrade all
sudo apt full-upgrade                          # may remove packages
apt list --installed | grep -i tree
apt-cache search keyword                       # search
apt-cache policy nginx                         # versions and origins

Lower-level dpkg:

dpkg -l                                        # all installed
dpkg -l tree                                   # status of one package
dpkg -s tree                                   # detailed status
dpkg -L nginx > /opt/course/26/nginx-files     # files installed by pkg
dpkg -S /usr/bin/vim > /opt/course/26/owner    # which pkg owns a file
sudo dpkg -i package.deb                       # install local .deb
sudo dpkg --configure -a                       # finish broken installs

Hold a package (prevents upgrade):

sudo apt-mark hold openssh-server
sudo apt-mark unhold openssh-server
apt-mark showhold

RHEL / Fedora — dnf + rpm§

sudo dnf install tree
sudo dnf remove tree
sudo dnf update                                # upgrade all
sudo dnf search keyword
sudo dnf info tree
sudo dnf provides /usr/bin/vim                 # which pkg owns a file
sudo dnf history                               # transaction log
sudo dnf history undo 42                       # roll back transaction
sudo dnf list installed
sudo dnf clean all
sudo dnf groupinstall "Development Tools"

Lower-level rpm:

rpm -qa                                        # all installed
rpm -qi tree                                   # info
rpm -ql nginx                                  # files in installed pkg
rpm -qf /usr/bin/vim                           # owning pkg
rpm -V nginx                                   # verify integrity
sudo rpm -ivh package.rpm
sudo rpm -e tree                               # erase

Version lock (RHEL):

sudo dnf install python3-dnf-plugin-versionlock
sudo dnf versionlock add openssh-server
sudo dnf versionlock list
sudo dnf versionlock delete openssh-server

Step 1 — Tree version§

sudo apt install -y tree
dpkg -s tree | awk '/^Version:/ {print $2}' > /opt/course/26/tree-version
# RHEL:
rpm -q --qf '%{VERSION}-%{RELEASE}\n' tree > /opt/course/26/tree-version

Repositories§

Debian: files under /etc/apt/sources.list and /etc/apt/sources.list.d/*.list.

RHEL: files under /etc/yum.repos.d/*.repo. Enable/disable:

sudo dnf config-manager --enable powertools
sudo dnf config-manager --add-repo https://example.com/repo.repo

GPG keys§

Debian: /etc/apt/trusted.gpg.d/ or /etc/apt/keyrings/. RHEL: rpm --import https://example.com/key.gpg.