Ivan Velichko

Hands-On Docker Roadmap 🐳

- Over 100 practical problems, from simple to advanced
- Realistic scenarios with automatic checks, hints, and editorial solutions
- 0% chance of getting into a tutorial hell trap
- Extra focus on the underlying Linux topics

labs.iximiuz.com/roadmaps/docker

Can a container reach a service on a host with UFW?

The answer is no. At least not by default. Containers reach host services through the bridge interface, and this is considered incoming traffic, which UFW denies by default.

Practice fixing it at labs.iximiuz.com/challenges/doc…

Folks are putting thousands of hours into hands-on learning on iximiuz Labs 💪

Linux 101: Hands-On Storage Management 🛠️

Practice the fundamentals of Linux storage management with a series of hands-on exercises - from mounting existing filesystems to partitioning drives and automating disk provisioning:

- Mount a drive with existing data and read its contents labs.iximiuz.com/challenges/sto…
- Create an ext4 filesystem on an unformatted drive labs.iximiuz.com/challenges/sto…
- Create a GUID Partition Table (GPT) on a blank drive labs.iximiuz.com/challenges/sto…
- Split a drive into multiple partitions and format them as ext4 and Btrfs labs.iximiuz.com/challenges/sto…
- Mount an existing directory at a new Location (bind mount) labs.iximiuz.com/challenges/sto…
- Make a filesystem mount survive a reboot labs.iximiuz.com/challenges/sto…
- Automate drive provisioning with a shell script labs.iximiuz.com/challenges/sto…

One of my favorite gotchas when using iptables or nftables instead of a more user-friendly firewall like ufw is that the rules you configure aren't persistent by default.

Rules added with 'iptables' or 'nft' commands exist only in the kernel's memory, so when the server reboots, the rules disappear, and the ports they protected can easily become exposed again.

Prepared a short hands-on series so you can experience it in a safe, controlled environment rather than in production 🙈

- Protect ports with firewall rules: labs.iximiuz.com/challenges/lin…

- Preserve iptables rules across server reboots: labs.iximiuz.com/challenges/lin…

- Preserve nftables rules across server reboots:
labs.iximiuz.com/challenges/lin…

Happy hacking!