Challenges

Focused hands-on problems designed to help you hone your DevOps or Server Side skills. Some challenges are more educational, while others are based on real-world scenarios. The platform provides hints and feedback for each challenge, including automated solution checks.

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This challenge was prepared for you by the iximiuz Labs team.

Challenge, Medium, on Linux

Start a systemd Service on the First Connection (TCP Socket Edition)

by Ivan Velichko

Configure systemd to keep a TCP port open at all times while starting the backing service process only when the first connection arrives.

systemd socket tcp

This challenge was prepared for you by the iximiuz Labs team.

Challenge, Medium, on Linux

Start a systemd Service on the First Connection (Unix Socket Edition)

by Ivan Velichko

Configure systemd to keep a Unix domain socket open at all times while starting the backing service process only when the first connection arrives.

systemd socket unix-socket

This challenge was prepared for you by the iximiuz Labs team.

Challenge, Medium, on Networking, Programming, Linux

Make One Echo Server Work with Both TCP and Unix Sockets

by Ivan Velichko

Make a single echo server listen on either a TCP socket or a Unix domain socket, selected by its command-line argument. The challenge illustrates that the same stream-socket workflow works with two address families (AF_INET and AF_UNIX).

socket tcp unix-socket

This challenge was prepared for you by the iximiuz Labs team.

Challenge, Medium, on Networking, Programming, Linux

Write a TCP Client for a Chat Server

by Ivan Velichko

Write a TCP client to hold a back-and-forth conversation with a "chat" server: send a line, read the reply, send another line - repeat until the session is over. A hands-on lesson in designing an application protocol on top of a byte-oriented TCP stream.

socket tcp

This challenge was prepared for you by the iximiuz Labs team.

Challenge, Easy, on Networking, Programming, Linux

Write a TCP Client for a Telemetry Server

by Ivan Velichko

Write your first TCP client for a push-only telemetry server that starts sending sensor readings as soon as you connect. Likely the easiest way to get started with TCP socket programming.

socket tcp

This challenge was prepared for you by the iximiuz Labs team.

Challenge, Medium, on Networking, Programming, Linux

Write a TCP Echo Server From Scratch

by Ivan Velichko

The Hello World of network programming: implement a tiny TCP echo server in the language of your choice.

socket tcp

This challenge was prepared for you by the iximiuz Labs team.

Challenge, Easy, on Linux

Troubleshoot a Worker Service That Keeps Disappearing

by Ivan Velichko

A systemd-managed worker process starts cleanly, prints a few heartbeat lines, then silently vanishes - over and over again. Diagnose why the process keeps dying and stabilize the service.

debugging systemd oom cgroups

This challenge was prepared for you by the iximiuz Labs team.

Challenge, Easy, on Linux

Troubleshoot an Image Conversion Daemon

by Ivan Velichko

An image conversion daemon was installed from a vendor package, but it fails to start. Diagnose why the binary cannot be loaded and fix the installation.

debugging os-packages ldd shared-library

This challenge was prepared for you by the iximiuz Labs team.

Challenge, Easy, on Linux

Troubleshoot a Log Shipping Daemon That Refuses to Start

by Ivan Velichko

A system daemon crashes on startup with a cryptic, non-actionable error message. Investigate the failure, identify its root cause, and get the service running.

debugging syscall strace

This challenge was prepared for you by the iximiuz Labs team.

Challenge, Medium, on Linux

Extract a tar Archive with Permissions, Ownership, and Extended Attributes Preserved

by Ivan Velichko

Practice extracting a container-style rootfs tarball while preserving the original file permissions, ownership, and extended attributes (including Linux capabilities).

tar