Focused, hands-on DevOps and server-side problems with hints, feedback, and automated solution checks.
An inventory service lives inside a private VPC and keeps its debugging port bound to 127.0.0.1. Use SSH local port forwarding with a jump-only bastion to query the debugging port from your workstation.
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.
A remote VM serves an app on port 80 and keeps an internal debugging port bound to 127.0.0.1. Reach the debugging port from your workstation using an SSH tunnel, without exposing it on the VM's external interface.
A production search cluster lives inside a private VPC and is reachable only from within it. Use SSH local port forwarding through a public-facing bastion host to query the cluster's API from your dev machine.
A payment webhook receiver runs as a local build on your dev machine, bound to 127.0.0.1 and invisible from the Internet. Use SSH remote port forwarding to publish it on a public-facing gateway VM so a test payment provider can reach it.
A status dashboard runs on an isolated device in your home network, with no inbound route from the Internet. Use SSH remote port forwarding with your workstation as a jump host to publish it on a public-facing gateway VM.
Several self-hosted services run on isolated devices in your home network, with no inbound route from the Internet. Use SSH dynamic remote port forwarding to turn a public-facing gateway VM into a single SOCKS proxy that reaches all of them.
Several internal microservices live inside a private VPC and are reachable only from within it. Use SSH dynamic local port forwarding to turn your dev machine into a single SOCKS proxy that reaches all of them through one bastion host.
Prove your networking skills by setting up an improvised proxy server with netcat.
Prove your networking skills by mapping one network address to another using socat.
