Execute Host Commands Inside a Running Container
Leverage your knowledge of Linux namespaces to reach an application's internal debug interface without installing anything into the container.
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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.
Leverage your knowledge of Linux namespaces to reach an application's internal debug interface without installing anything into the container.
Learn how to run multiple Docker containers sharing the same PID, IPC, and network namespaces - a foundation of many advanced container use cases, including Kubernetes Pods construction and container debugging tools.
Explore the key container management operations by walking through all the phases of the container lifecycle - from creation to termination and removal.
Practice pausing and resuming a running container: start a resource-hungry container, pause it, inspect its state, and then unpause it back to life.
Practice pausing (freeze) and resuming (thaw) a resource-hungry Linux process using the cgroup v2 freezer mechanism.
Practice using UNIX signals with containers for controlling application behavior: Send a SIGUSR1 to a containerized app to trigger its memory usage reporting.
Learn how to configure the restart policy for a container so that it restarts automatically on application failure.
Your Docker host has been in use for a while. Anonymous and named volumes piled up, disk space is tight, and it's time to clean stuff up.
Learn the difference between named and anonymous volumes and avoid accidental data loss when upgrading a database container.
Learn how to persist the application's on-disk state using a volume so you can replace a container with a newer version while keeping existing data intact.