learnbyfixing.com

Learn by Doing. Understand by Fixing.
Improve your Linux, DevOps and SRE skills by solving real‑world challenges

[learnbyfixing.com @learnbyfixing]

The platform team shared one simple instruction for the new GPU-enabled Kubernetes cluster: Add "gpu=enabled" to your workloads.
A teammate deployed an ML inference application with the correct affinity configuration… yet every pod is stuck in "Pending".

https://t.co/unQigZEA9H

[learnbyfixing.com @learnbyfixing]

A new marketing campaign will increase traffic to your infra.
A legacy pod may not be able to handle it.
The app is critical and can't be restarted.
You tried "kubectl edit", but it didn't work.

Can you double the CPU for the pod with zero downtime?

https://t.co/1e6GRvVPmx

[learnbyfixing.com @learnbyfixing]

A dev on your team suggests this:
1. Copy an API key into the Docker image during build
2. Set up the app
3. Delete the file

"The file won’t be in the final Docker image, so it’s safe."

Your challenge: Find the API key hidden in the Docker image.

https://t.co/I2yz8CyxYo

[learnbyfixing.com @learnbyfixing]

Struggling with Docker issues? This new troubleshooting roadmap can help:

https://t.co/TnVVDLtBUI

It brings together practical guides and structured skill paths to sharpen your Docker debugging abilities.

#LearnByFixing #DevOps #SRE #Sysadmin #Docker

[learnbyfixing.com @learnbyfixing]

New guide released: Namespaces and nsenter

It starts from a simple challenge, but every time you solve it, a new constraint is added, and you have to figure out another way to crack it.

https://t.co/Cw3hUYTQHc

[learnbyfixing.com @learnbyfixing]

Your team has just inherited a legacy Docker image with no docs.

No ports are exposed and the logs are unhelpful.

Right now, the application running inside the container is completely inaccessible.

Can you find and expose the port?

https://t.co/Yum3YbSfAb

[learnbyfixing.com @learnbyfixing]

A Docker container can't connect to its own DB, but why?
- DNS resolution?
- Network connectivity?
- Rootless Docker misconfig?
- Or all three at once?

Most container issues aren’t where you think they are.

https://t.co/w196IIlGYf

#LearnByFixing #DevOps #SRE #Sysadmin #Docker

[learnbyfixing.com @learnbyfixing]

Most people don't fail at learning Linux troubleshooting… They just don't know what to learn next.

Check out this Linux Troubleshooting Roadmap if you want to:

- Improve your skills
- Stop jumping between random topics
- Follow a clear, practical path

https://t.co/Lx1yJfal9a

[learnbyfixing.com @learnbyfixing]

New guide released: Signals in Docker

- Why PID 1is important inside a container
- docker stop vs docker kill
- How to make containers shut down gracefully
- How to send signals to containers

https://t.co/T6wsAY39CF

[learnbyfixing.com @learnbyfixing]

What is the most effective way to strengthen your troubleshooting skills?

Practice in real scenarios.

We’ve published a GitHub repository with descriptions of all our scenarios, allowing you to explore them and challenge yourself:

https://t.co/oo7lwGAeRi

[learnbyfixing.com @learnbyfixing]

New scenario released! 🚀

An app was set up locally using Docker Compose... but it doesn't start.

It has 3 services: proxy, app and database.

Can you make it work?

https://t.co/tQQLTX6Q8p

Happy fixing!

#LearnByFixing #DevOps #SRE #Sysadmin #Docker

[learnbyfixing.com @learnbyfixing]

New scenario released! 🚀

You tried to start a containerized app, but it doesn't run.

A colleague says it works on their laptop.

Can you make it run without changing the app's code?

https://t.co/mvii8AnM20

Happy fixing!

#LearnByFixing #DevOps #SRE #Sysadmin #Docker

[learnbyfixing.com @learnbyfixing]

New scenario released! 🚀

A Docker image was built to deploy an app to production… but there’s a problem.

It's over 1 GB.

Your mission: optimize its size to be under 20 MB.

Can you fix it?
https://t.co/xfKRmVG7Vl

Happy fixing!

#LearnByFixing #DevOps #SRE #Sysadmin #Docker

[learnbyfixing.com @learnbyfixing]

🚀 Big Update: From Tutorials to Real Challenges

Our labs are now real challenges, featuring:

- A "Check Solution" button
- Optional hints if you get stuck
- Full solution reveal when you're ready

https://t.co/vrzmsRxBYP

#LearnByFixing #DevOps #SRE #Sysadmin #Linux #Docker

[learnbyfixing.com @learnbyfixing]

Instant DevOps Labs: Hands-On & Free! 🚀

Get 15 minutes of real Linux environment practice with genuine scenarios.

No signup. No email. No credit card required.

https://t.co/vrzmsRxBYP

#LearnByFixing #DevOps #SRE #Sysadmin #Linux #Docker

[learnbyfixing.com @learnbyfixing]

New features are here! 🚀

We’ve just launched two highly requested improvements:

- Skill-level filtering in Scenarios
- Seamless access using your GitHub account

Ready to dive in and get hands-on? https://t.co/21cf93pzEy

#LearnByFixing #DevOps #SRE #Sysadmin #Linux

[learnbyfixing.com @learnbyfixing]

New scenario released! 🚀

Reload the configuration of a containerized app without restarting the Docker container.

Sounds easy? Not so much when the container uses a distroless image.

https://t.co/6q4upWyU9p

Happy fixing!

#LearnByFixing #DevOps #SRE #Sysadmin #Docker

[learnbyfixing.com @learnbyfixing]

We have just expanded the Environment Variables guide to include their use in Docker containers:

https://t.co/JH6NfGWYil

#LearnByFixing #Linux #DevOps #SRE #Sysadmin #Docker #Containers #EnvironmentVariables

[learnbyfixing.com @learnbyfixing]

New scenario released! 🚀

You have a verbose Docker container.
Your challenge: make it log ERROR messages only without modifying the image.

Sharpen your Docker skills and try it now:
https://t.co/nDtMWEL1P7

Happy fixing!

#LearnByFixing #Linux #DevOps #SRE #Sysadmin #Docker

[learnbyfixing.com @learnbyfixing]

New free guide released! 🚀

Do you want to troubleshoot Linux like a pro? Our latest free guide shows you how to inspect system calls using strace.

https://t.co/tyaJ8gXyRE

#LearnByFixing #Linux #DevOps #SRE #Sysadmin #syscalls #strace