Courses to Read Along
The complete theory and all tasks of the 22 Lab courses, free to read without signing up. To practise on a real Linux VM, a free account is all you need.
First steps
3 courses
Hello World
Your start in the lab: in a few minutes you learn how the automatic check verifies your solutions on the real VM — and you finish by blocking root login via SSH. 4 short tasks.
10 min · Beginner
Linux Users and Permissions
You learn the Linux user and permission system: create users and groups, grant sudo access, set file ownership and access rights, and understand SUID risks.
60 min · Beginner
Linux Console
First steps with the Linux shell.
20 min · Beginner
Securing servers
5 courses
SSH Hardening
You harden your server VM's SSH configuration against the most common attack vectors — disable root login, switch off password auth, limit login attempts, detect dead connections with keep-alive. 7 tasks, about 60 minutes.
60 min · Beginner
UFW + fail2ban
You set up a basic server firewall with UFW (default deny + whitelist) and protect SSH against brute-force attempts using fail2ban. 6 tasks, about 55 minutes.
55 min · Beginner
nginx TLS Hardening
You harden nginx from an insecure default state (self-signed snakeoil cert + TLSv1 enabled + permissive ciphers + no security headers) into a modern TLS configuration. 7 tasks, about 60 minutes.
60 min · Intermediate
Linux Firewall with nftables
You learn nftables — the modern successor to iptables, now the default on 75% of Linux servers.
75 min · Intermediate
Secure Docker Containers
You harden a Docker installation following the CIS Docker Benchmark: eliminate root containers, restrict capabilities, enable read-only filesystems, configure network isolation, and secure the Docker daemon.
90 min · Advanced
Web servers & containers
3 courses
Deploy a live website with HTTPS
Within an hour you'll get your own website online — with a valid HTTPS certificate from Let's Encrypt, your own subdomain, and real nginx.
30 min · Beginner
nginx as a reverse proxy
You put nginx in front of a python3 backend that only listens on 127.0.0.1:9000.
40 min · Beginner
Docker Basics: your first container
You learn the building blocks of Docker on your lab VM: pulling images, running containers, port mapping, container lifecycle.
30 min · Beginner
Attack & defense
5 courses
Web Security for Students
Passwords, phishing, HTTPS, cookies, 2FA. 5 short tasks documented in text files — no hacking, just knowledge.
25 min · Beginner
Pentest Basics: SSH Brute Force
First offensive module: you attack a deliberately weak SSH instance.
45 min · Intermediate
Log Analysis: spot SSH attacks in auth.log
The defender side of the pentest lesson: your VM has 200 synthetic SSH brute-force entries in /var/log/auth.log.
30 min · Intermediate
Fix the server
Debug challenges: you get a broken server and no instructions.
45 min · Intermediate
Incident Response with journald
A server has been compromised.
90 min · Advanced
Programming & data
6 courses
HTML Basics
Build your very first webpage. 5 short tasks — tags, headings, paragraph, link, image.
25 min · Beginner
Markdown + Data Formats
Write your first Markdown note and learn JSON + CSV. 5 short tasks, each 2-3 minutes.
20 min · Beginner
Python Basics
First steps with Python: print, variables, if/else, loop, function.
30 min · Beginner
Git Basics
Understand version control with git.
25 min · Beginner
SQL Basics
SELECT, WHERE, INSERT, JOIN, GROUP BY. Write 5 SQL statements into a .sql file.
30 min · Beginner
Working with CSV data
Create a CSV table and filter rows with Linux tools (grep, awk, sort).
25 min · Beginner
Questions we get asked a lot
Are the courses really free?
Yes. The full theory and all exercises are freely readable without signing up. A free account is only needed to practise on a real Linux VM.
Do I need an account to read the content?
No. The courses are fully readable without signing up. You only need an account once you want to solve the exercises on a Linux VM yourself.
Do I have to install anything?
No. The courses run in the browser, and so does the Linux VM. There is nothing to set up and nothing to download.
May I use the material in my teaching?
Yes. Lab content is published under CC BY 4.0 and may be used freely with attribution (© TechLogia).
What do the difficulty levels mean?
Beginner assumes no prior knowledge. Intermediate expects command-line basics. Advanced is aimed at people who already run servers.
Which topics are covered?
Among others SSH hardening, Docker, nginx, firewalls, log analysis, Python, Git and SQL — from Linux basics through server hardening to incident response.