Linux Administrator -> DevOps Learning Repository

Linux Ubuntu Bash VirtualBox Openssh -> DevOps Tools

About Me

Hi. I'm Sachin - a System Administrator with 4+ years of experience, currently transitionig into DevOps and Linux Engineering. This repository documents my hands-on learning journey through structured labs covering Linux administration, DevOps tools, troubleshooting, and real-world projects — one module at a time. 🔗 LinkedIn 📧 sachinshady6@gmail.com

Project Overview

Category	Details
Project Type	Linux System Administration & DevOps Labs
Focus	Practical Linux & DevOps skills
Environment	VirtualBox with Ubuntu & Kali Linux; Devops tools on Linux
Topics Covered	Users, SSH Hardening, Services, Logs, LVM, Backups, Cron, Networking, Firewall, Bash, Git, Docker, CI/CD, Terraform, Kubernetes, Ansible, Monitoring
Learning Method	Hands-on labs, real-world troubleshooting, structured modules

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Table of Contents

• Skills Learned
• Repository Structure
• Learning Progress
• Real-World Troubleshooting Scenarios
• Labs
• Environment Used
• Goal

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Skills Learned

• Linux Administration: Users/groups, SSH hardening, Services, Logs, Disk and storage management, Backups, Cron, Networking, Firewall, Bash scripting
• Devops Tools: Git, Docker, Jenkins, CI/CD, Kubernetes, Terraform, Ansible, Monitoring
• Troubleshooting: Logs, Services, Network, Cron, Disk, SSH, Firewall
• Automation & Infrastructure Management: Scripts, Pipelines, IaC, Deployment All labs are performed on a Linux environment using VirtualBox + Ubuntu/Kali.

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Repository Structure

U-Series (Linux Foundation)

Module	Topic
U1	Linux Basics
U2	SSH Hardening
U3	Service Management (systemd)
U4	Logs (journalctl deep dive)
U5	Disk Management (LVM)
U6	Backup Concepts
U7	Cron Automation
U8	Networking Troubleshooting
U9	Firewall (ufw / iptables)
U10	Basic Bash Scripting

D-Series (DevOps Tools)

Module	Topic
D1	Git & GitHub
D2	CI/CD Fundamentals
D3	Jenkins
D4	Docker
D5	Docker Networking
D6	Docker Compose
D7	Kubernetes
D8	Terraform
D9	Ansible
D10	Monitoring

T-Series (Troubleshooting Labs)

Module	Topic
T1	User & Permission Issues
T2	SSH Access Problems
T3	Service Failures
T4	Log Investigation
T5	Disk & LVM Problems
T6	Network Troubleshooting
T7	Performance & Resource Issues

P-Series (DevOps Projects)

Module	Topic
P1	Git Workflow
P2	Networking for DevOps
P3	Dockerized Applications
P4	CI/CD Pipelines
P5	Infrastructure as Code
P6	Kubernetes Deployment
P7	Cloud Fundamentals
P8	Monitoring & Logging
P9	DevSecOps
P10	Real DevOps Project

O-Series (OS/Distro Building)

Module	Topic
O1	Boot Process
O2	Package Building (.deb)
O3	Live-build / ISO
O4	Kernel Basics
O5	Custom Repo
O6	Branding & Release
O7	DistroWatch Submission

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Learning Progress

Module	Topic	Status
U1	Linux Basic	✅ Completed
U2	SSH Hardening	✅ Completed
U3	Service Management (systemd)	✅ Completed
U4	Logs (journalctl deep dive)	✅ Completed
U5	Disk Management (LVM)	✅ Completed
U6	Backup Concepts	✅ Completed
U7	Cron Automation	✅ Completed
U8	Networking Troubleshooting	✅ Completed
U9	Firewall (ufw / iptables)	✅ Completed
U10	Basic Bash Scripting	✅ Completed
Module	Topic	Status
------	------	------
D1	Git & GitHub	✅ Completed
D2	CI/CD Fundamentals	✅ Completed
D3	Jenkins	✅ Completed
D4	Docker	✅ Completed
D5	Docker Networking	✅ Completed
D6	Docker Compose	✅ Completed
D7	Kubernetes	✅ Completed
D8	Terraform	✅ Completed
D9	Ansible	✅ Completed
D10	Monitoring	✅ Completed
Module	Topic	Status
------	------	------
T1	User & Permission Issues	✅ Completed
T2	SSH Access Problems	✅ Completed
T3	Service Failures	✅ Completed
T4	Log Investigation	✅ Completed
T5	Disk & LVM Problems	✅ Completed
T6	Network Troubleshooting	✅ Completed
T7	Performance & Resource Issues	✅ Completed
Module	Topic	Status
------	------	------
P1	Git Workflow	✅ Completed
P2	Networking for DevOps	✅ Completed
P3	Dockerized Applications	🆕 Upcoming
P4	CI/CD Pipelines	🆕 Upcoming
P5	Infrastructure as Code	🆕 Upcoming
P6	Kubernetes Deployment	🆕 Upcoming
P7	Cloud Fundamentals	🆕 Upcoming
P8	Monitoring & Logging	🆕 Upcoming
P9	DevSecOps	🆕 Upcoming
P10	Real DevOps Project	🆕 Upcoming
Module	Topic	Status
------	------	------
O1	Boot Process	🆕 Upcoming
O2	Package Building (.deb)	🆕 Upcoming
O3	Live-build / ISO	🆕 Upcoming
O4	Kernel Basics	🆕 Upcoming
O5	Custom Repo	🆕 Upcoming
O6	Branding & Release	🆕 Upcoming
O7	DistroWatch Submission	🆕 Upcoming

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Real-World Troubleshooting Scenarios

• Troubleshooting SSH connection failures
• Diagnosing service startup issues using systemd and journalctl
• Investigating system logs to trace root cause of failures
• Identifying blocked ports using firewall rules
• Analyzing network connectivity problems
• Automating repetitive tasks using Bash scripts
• Diagnosing DNS resolution failures and fixing via systemd-resolved

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Labs

Each Module in this repository includes:

• Practical lab exercises
• Real Linux administration commands
• Troubleshooting scenarios
• Notes and explanations

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Environment Used

• VirtualBox
• Ubuntu Linux
• Kali Linux
• OpenSSH
• Linux CLI tools

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Lab Environment

All labs were performed inside a controlled virtual lab environment.

Host Machine
│
├── VirtualBox
│
├── Ubuntu VM (Linux Administration Practice)
│
└── Kali Linux VM (Security / SSH / Networking Tests)

The lab setup allows safe testing of:

• SSH hardening
• firewall rules
• service failures
• networking troubleshooting
• automation scripts DevOps Environment
• Docker
• Jenkins
• Kubernetes
• Terraform
• GitHub
• CI/CD Pipelines

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Goal

To become a professional Linux System Administrator and DevOps engineer through structured learning, hands-on labs and real-world labs.

Author

Sachin M - Linux & DevOps Learning Journey 🔗 LinkedIn | 📧 sachinshady6@gmail.com