Day 7/90 - #90daysofdevops
What is a package manager?
A package manager is a tool in Linux that is used to install, remove, update, and upgrade software packages on a Linux-based operating system. Using a package manager is one of the most efficient and secure ways to manage software on a Linux system, as it automates the process of installation and updates, reducing human errors and ensuring the system is kept in a stable state.
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). The package is like a gift box that contains all the software needed to install and run the program on your computer. It makes it easy to get new software, keep it updated and remove it when you don't need it. It is managed by the package manager.
Different kinds of package managers?
Here are some of the commonly used package managers in different Linux distributions:
APT (Advanced Package Tool): Used in Debian and Debian-based distributions, such as Ubuntu, Linux Mint, and elementary OS. It works with .deb packages.
Yum (Yellowdog Updater, Modified): Historically used in Red Hat Enterprise Linux (RHEL), CentOS, and older Fedora versions. It has been replaced by DNF in newer Fedora versions.
DNF (Dandified Yum): The successor to Yum, used in modern Fedora versions and CentOS 8 and above.
Each package manager has its own commands and syntax, but they all do the same things like installing software, keeping it updated, and removing it when it's not needed.
Installing Docker and Jenkins in your system from your terminal using package managers.
To install Docker and Jenkins in your system on Ubuntu or CentOS, open your terminal and use the following commands:
Installing Docker on Ubuntu:
$sudo apt-get update
$sudo apt-get install docker.io
Installing Docker on CentOS:
$sudoy yum update
$sudo yum install docker
Installing Jenkins on Ubuntu:
$sudo apt-get update
$sudo apt-get install jenkins
Installing Jenkins on CentOS:
$sudo yum update
$sudo yum install jenkins
systemctl and systemd
In Linux, systemctl and systemd are two essential components related to managing and controlling system services. systemd is a system and service manager for Linux operating systems. systemctl is the command-line interface to control and interact with the systemd system and service manager.
Check the status of the docker service in your system:
To check the status of the docker service in your system use the following command:
$systemctl status docker
Stop the service of Jenkins
To stop the service of Jenkins simply use the following command:
$sudo systemctl stop jenkins
The commands of systemctl vs service
Both systemctl and service are used to control services, but the systemctl is new and more powerful.
The command to check docker status in systemctl and service use:
systemctl:
$systemctl status docker
service:
$service docker status
Commands of systemctl:
- To start a service:
sudo systemctl start service_name
- To stop a service:
sudo systemctl stop service_name
- To restart a service:
sudo systemctl restart service_name
- Check the status of a service:
sudo systemctl status service_name
Commands of service:
- To start a service:
sudo service service_name start
- To stop a service:
sudo service service_name stop
- To restart a service:
sudo service service_name restart
- Check the status of a service:
sudo service service_name status
That's a spoonful of knowledge from the whole ocean. I hope this blog was helpful to you. Keep learning!.