Understanding package manager and systemctl

What is a package manager in Linux?

In simpler words, a package manager is a tool that allows users to install, remove, upgrade, configure and manage software packages on an operating system. The package manager can be a graphical application like a software center or a command lines tool like apt-get or pacman.

You’ll often find me using the term ‘package’ in tutorials and articles, To understand package manager, you must understand what a package is.

What is a package?

A package is usually referred to as an application but it could be a GUI application, command line tool or a software library (required by other software programs). A package is essentially an archive file containing the binary executable, configuration file and sometimes information about the dependencies.

Different kinds of package managers

Package Managers differ based on the packaging system but the same packaging system may have more than one package manager.

For example, RPM has Yum and DNF, package managers. For DEB, you have apt-get, aptitude command line-based package managers.

Tasks

You have to install docker in your system from your terminal using package managers

1) Update the apt package index and install packages to allow apt to use a repository over HTTPS:

2) Add Docker’s official GPG key:

3) Use the following command to set up the repository:

4) Update the apt package index:

5) Install Docker Engine, containerd, and Docker Compose.

6) Check if docker is installed properly

You have to install jenkins in your system from your terminal using package managers

1) Install Java

2) Check if Java is installed

3) Add the framework repository key

4) Install Jenkins

systemctl and systemd

systemctl is used to examine and control the state of “systemd” system and service manager. systemd is a system and service manager for Unix-like operating systems(most of the distributions, not all).

Thank you for reading.

Bikram Chatterjee