Tutorials

Deep dives into DevOps and server-side topics, combining theory with hands-on examples. Run every command in an attached remote playground, from your browser or local terminal over SSH — no setup required.

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Tutorial

How Container Filesystem Works: Building a Docker-like Container From Scratch

Learn how Linux containers are built from the ground up. Starting with the mount namespace and a root filesystem, see why PID, cgroup, UTS, and network namespaces naturally follow - and how this foundation makes concepts like bind mounts, volumes, and persistence in Docker or Kubernetes much easier to grasp.

How Container Filesystem Works: Building a Docker-like Container From Scratch (cover image)
Tutorial

Native SSH Reverse Tunneling with Pomerium

Use Pomerium's native SSH support to publish a local service through a standard reverse SSH tunnel, with OpenID Connect (OIDC) authentication and continuous authorization on every request. Reach services behind Network Address Translation (NAT) without firewall holes or custom agents, and control both who can use the service and who can open the tunnel. Application traffic stays on infrastructure you control.

Native SSH Reverse Tunneling with Pomerium (cover image)
Tutorial

Containers are processes

In this brief tutorial we'll explore the idea that Docker containers are just processes, from the perspective of the operating system. Based on this Securitylabs blog post https://securitylabs.datadoghq.com/articles/container-security-fundamentals-part-1/

Containers are processes (cover image)