![[ Day-7 ]: Understanding package manager and systemctl](https://cdn.hashnode.com/res/hashnode/image/upload/v1697111338997/79538b51-7971-47ef-8bd3-1cacec4a1f33.png?w=1600&h=840&fit=crop&crop=entropy&auto=compress,format&format=webp)
Introduction 📚
Welcome to Day 7 of the thrilling #90DaysOfDevOps challenge. In this blog, we will embark on an exploration of the package manager and its essential tools. We will dive into the world of APT (Advanced Package Tool) 🛠️ and YUM (Yellowdog Updater Modified) 🛠️. Alongside this, we'll be understanding the significance of systemctl and systemd.
By the end of this read, you will have a clear pathway on installing Docker 🐳 and Jenkins 🏗️ using package managers. And yes, for Docker, we shall be configuring the repository, and for Jenkins, we will be using APT on Ubuntu. Moreover, get ready to become proficient in checking the Docker service status, halting Jenkins service, and distinguishing between systemctl and service commands.
Now, buckle up as we delve into this exciting journey, aiming to harness the potential of streamlined software management within the Linux environment! 🚀
📦 What is a package?
In Linux, a package is more than just a piece of software. It's a comprehensive distribution format containing all that's necessary to install and manage a particular software. This typically includes:
Executable binaries 💾: The actual software applications.
Libraries 📚: Shared resources the software needs to function.
Configuration files 📝: Settings and parameters for software operation.
Documentation 📄: Guides, manuals, and other helpful insights to aid users.
🧰 What is a package manager in Linux?
To simplify, a package manager is the caretaker of your Linux software. It automates the installation, updates, and removal of software packages. But let's dive a little deeper:
Simplification: Managing software becomes a breeze as package managers handle dependencies.
Consistency and Reliability: Ensures uniform software installations across the system.
Centralized Access: Users can tap into a centralized repository to find and install software. No more hunting around on the internet.
Enhanced Stability and Security: By managing software components efficiently, package managers promote a stable and secure system.
In essence, a package manager is an indispensable tool for Linux, responsible for juggling installations, upgrades, dependencies, and the removal of packages.
▪️ Different Kinds of Package Managers
In the Linux ecosystem, while there are several package managers, APT (Advanced Package Tool) and YUM (Yellowdog Updater Modified) stand out due to their widespread use and reliability. Let's delve into them:
1. APT (Advanced Package Tool) 🛠️
Originating from the Debian camp, APT is the go-to package manager for Debian-based distributions such as Ubuntu. It is heralded for its user-friendly command-line interface, which provides ease in software management.
Key commands include:
Install a package:
sudo apt-get install package_nameUpdate packages:
sudo apt-get update
sudo apt-get upgrade
- Remove a package:
sudo apt-get remove package_name
APT's standout feature is its prowess in resolving package dependencies automatically. You never have to manually chase down required packages. APT handles it all, ensuring a smooth and conflict-free installation process.
2. YUM (Yellowdog Updater Modified) 🛠️
A favorite in Red Hat-based distributions like CentOS and Fedora, YUM offers a comparable command-line interface for package management, ensuring ease of software installations.
Primary commands encompass:
Install a package:
sudo yum install package_nameUpdate packages:
sudo yum update
sudo apt-get upgrade
- Remove a package:
sudo yum remove package_name
Similar to APT, YUM shines in dependency management. Every time you task YUM with an installation or an update, rest assured that it will diligently resolve dependencies, guaranteeing that all necessary packages get appropriately installed.
🔍 Deep Dive into Systemctl and Systemd
Linux provides a gamut of tools that streamline program and service management. Among these, systemctl and systemd are integral.
Systemd 🎻: Think of systemd as the conductor of an orchestra. It orchestrates how programs and services harmonize on your computer, ensuring a smooth performance.
Systemctl 🎮: If systemd is the conductor, then systemctl is the remote control. It gives you command over the conductor, dictating starts, stops, and everything in between.
Essential systemctl commands include:
Start a service:
sudo systemctl start service_nameStop a service:
sudo systemctl stop service_nameRestart a service:
sudo systemctl restart service_nameEnable a service:
sudo systemctl enable service_nameDisable a service:
sudo systemctl disable service_name
With systemctl, managing services, from web servers to background tasks, becomes intuitive and efficient.
🐳 Task 1: Installing Docker and Jenkins Using Package Managers
🚀 Objective: Harness the power of package managers to install Docker and Jenkins on an Ubuntu system. Let's get started!
Installing Docker on Ubuntu using APT:
- Update the package lists 🔄:
sudo apt update
- Install the Docker repository 📦:
sudo apt-get install docker.io -y
- Verify Docker Installation 🚀: Check the installed version of Docker:
docker version
Installing Jenkins on Ubuntu using APT:
- Pre-requisites: Jenkins requires Java to function. Update the Debian apt repositories and install OpenJDK 17:
sudo apt update
sudo apt install openjdk-17-jre
java -version
- Set Up Jenkins Repository: Import the Jenkins Long-Term Support release key and add the repository:
curl -fsSL https://pkg.jenkins.io/debian-stable/jenkins.io-2023.key | sudo tee /usr/share/keyrings/jenkins-keyring.asc > /dev/null
echo deb [signed-by=/usr/share/keyrings/jenkins-keyring.asc] https://pkg.jenkins.io/debian-stable binary/ | sudo tee /etc/apt/sources.list.d/jenkins.list > /dev/null
sudo apt-get update
- Install Jenkins:
sudo apt-get install jenkins
Manage Jenkins Service:
- Start the Jenkins service:
sudo systemctl start jenkins
- Enable Jenkins to automatically start on boot:
sudo systemctl enable jenkins
- Access Jenkins: Jenkins should now be active and running on your Ubuntu system. Open your web browser and navigate to http://localhost:8080 to access the Jenkins dashboard.
🔦 Task 2: Checking the Status of the Docker Service
After the successful installation of Docker on your system, it's essential to monitor its status. A quick way to accomplish this is by utilizing the systemctl command.
Checking Docker's Status:
Run the following command to see the current status of the Docker service:
systemctl status docker
This command's output will offer insights such as the Docker service's operational state, its auto-start configuration, and recent logs, ensuring that Docker operates seamlessly on your platform. 👍🚀
🛑 Task 3: Stopping the Jenkins Service
There might be instances where you'd want to halt the Jenkins service temporarily.
Stopping Jenkins:
Execute the following command to cease the Jenkins service:
sudo systemctl stop jenkins
Upon execution, Jenkins will remain inactive on your system until you decide to restart it.
💡 Difference between systemctl and service
Both systemctl and service serve as commands to handle services in Linux. However, their functionalities and applications possess certain distinctions.
systemctl:
Introduced with systemd, the default init system in numerous contemporary Linux distributions, systemctl is a potent service management utility. It's known for its expansive functionalities, enabling users to:
Start, stop, and restart services
Enable or disable services at boot
Inspect service statuses
Example: To verify the Docker service's status using systemctl, deploy the following command:
systemctl status docker
service:
service, a legacy tool from init-based systems (SysVinit), primarily exists for backward compatibility in many Linux distributions. While it is gradually making an exit in favor of systemctl, it still offers basic functionalities like starting, stopping, and restarting services.
Example: To review the Docker service's status with service, use this command:
service docker status
While both tools offer capabilities to manage services, systemctl stands out due to its comprehensive features and widespread adoption in modern Linux systems. ⏳
That's an excellent conclusion! It provides a comprehensive recap of the topics covered during the day, gives a sense of accomplishment, and excites the reader for the next stages of the challenge. I don't see a need for any major changes. However, if you want to further refine it, consider the following format:
🎉 Conclusion 🎉
Bravo! You've successfully navigated through Day 7 of the #90DaysOfDevOps challenge! 🚀
Today was an enlightening dive into:
The universe of packages and their trusty sidekicks - the package managers 📦
The essentials of systemctl and systemd, unlocking the capabilities to seamlessly manage services 🔄
Installation magic with Docker and Jenkins, making complex tasks feel like a breeze 🐳🔧
Distinguishing between systemctl and service for adept service management 💡
With these tools and knowledge, you've not only expanded your tech toolkit but also prepped yourself for challenges that lie ahead.
📌 Remember: Every day, every task, adds a brick to the edifice of your DevOps expertise.
Onward and upward! Get set for more exhilarating adventures in the world of DevOps! 💪🌟