Challenges

Official Collection

Challenges crafted by iximiuz Labs to help you master DevOps and Server Side topics.

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

Challenge on Linux

Verify Downloaded Files with SHA-256 Checksums

Practice using SHA-256 checksums to verify file integrity, detect corrupted or modified files, and confirm that downloaded data matches the original.

#sha256 #checksums #linux-101

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

Challenge on Linux, Networking

Call an HTTP API with curl: Authenticating with Basic Auth and Bearer Tokens

by Ivan Velichko

Practice authenticating to an HTTP API from the command line using both a username and password and a bearer token, and learn a couple of tricks along the way.

#curl #http #authentication #linux-101

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

Challenge on Containers, Linux

Reach a Distroless Container's Debug Endpoint From a Sidecar Container

by Ivan Velichko

A distroless container serves a debug interface on its own loopback address. Can you reach this debug endpoint using nothing but standard Docker commands?

#docker #namespaces #container-networking #debugging #distroless

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

Challenge on Kubernetes, Networking

Identify the Source of Unexpected Requests in a Kubernetes Cluster

by Ivan Velichko

An internal service started receiving requests from unexpected IP addresses. Identify the unexpected sources and find out which workloads and teams are behind them.

#kubectl #ip #investigation

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Independent Authors

Challenges from outstanding independent authors proudly hosted by iximiuz Labs.

This challenge was carefully crafted by an independent author and proudly hosted by iximiuz Labs.

Challenge on Kubernetes

Kube Mysteries: The Invisible Pod

by Márk Sági-Kazár

Did you know that pods can become invisible? Can you figure out how?

#kubelet #pod

This challenge was carefully crafted by an independent author and proudly hosted by iximiuz Labs.

Challenge on Linux, Programming

In this challenge, you’ll debug and fix a deliberately “broken” eBPF program, then prove it’s running by identifying its program and map IDs. Along the way, you’ll explore bpftool, check which helpers are supported, and dig into details like the UID of the loader. Finally, you’ll test your knowledge of eBPF maps by recalling the flag that only inserts a key if it doesn’t already exist.

#eBPF

This challenge was carefully crafted by an independent author and proudly hosted by iximiuz Labs.

Challenge on CI/CD, Security

Dagger: Working with Secrets

by Márk Sági-Kazár

Get hands-on with reading secrets from different providers and using them in your Dagger pipelines.

#dagger

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Community Collection

Challenges contributed by the community members sharing their knowledge and expertise.

This challenge was created by a community author. Community content is reviewed by the iximiuz Labs team on a best effort basis.

Challenge on Kubernetes

Node Is Ready, but Pods Won't Schedule

by Omkar Shelke

node-02 is back from a kernel upgrade but still shows Ready,SchedulingDisabled, and the Pods that can only run on it are stuck in Pending. Bring the node back into service and get the workload running, without touching the workload itself.

#cka #scheduling #nodes #troubleshooting

This challenge was created by a community author. Community content is reviewed by the iximiuz Labs team on a best effort basis.

Challenge on Kubernetes

CKA Practice: Recover a NotReady Node After a Kubelet Configuration Error

by Shiva Swaroop N K

A worker node dropped to NotReady and part of the workload went with it. The container runtime is fine and the control plane is healthy; the trail leads from kubectl symptoms down into systemd and the kubelet configuration. Diagnose the node and bring it back.

#cka #kubelet #nodes #troubleshooting

This challenge was created by a community author. Community content is reviewed by the iximiuz Labs team on a best effort basis.

Challenge on Kubernetes, Containers

Kubernetes - Multi-Container Pod Design Patterns

by Kaloyan Preslavski

Build five ways to combine containers in one Pod: a sidecar that extends the app, an init container that finishes before the app starts, a native sidecar with a startup guarantee, an ambassador that mutates an outbound call, and an adapter that translates an inbound one.

#pod-patterns #sidecar #ambassador #adapter #init-containers