Restrict SSH Bastion Access by User Role
Harden a bastion host so only admins can get a shell on it, operators can open tunnels to arbitrary destinations, and developers can reach only the one internal service they actually need.
Submissions: 57/94
Challenges
Focused, hands-on problems for sharpening your DevOps and server-side skills. Some teach specific concepts while others mirror real-world scenarios. Every challenge includes hints, feedback, and automated solution checks.
Challenge, Hard, on
Split a Drive into Multiple Partitions And Format Them as Ext4 and Btrfs
Create two partitions on a blank disk: one smaller ext4 for service logs and the rest btrfs for service data. Mount both and prove they work.
Submissions: 174/299
Make a Kubernetes Pod Survive an OOM Event Without Restarting
Hack your way through this challenge making the OOM kills invisible again.
Submissions: 133/470
Forward a Port Without Starting a Proxy Process
Prove your networking skills by mapping one network address to another without starting any additional processes.
Submissions: 274/597
Reproduce a Docker Bridge Network Using Basic Linux Commands
The culmination of the Docker networking challenges series. Can you create a Docker-like bridge network from scratch and using nothing but basic Linux commands.
Submissions: 231/431
Connect Multiple Network Namespaces
Prove your mastery of Linux and containers by connecting multiple network namespaces into a single network.
Submissions: 333/766
Network Access to a Container Started by ctr
Learn a bunch of Linux networking tricks while trying to access an Nginx server running inside a container started with ctr and a bare containerd daemon.
Submissions: 197/267