Challenge, Medium, on
Start a systemd Service on the First Connection (TCP Socket Edition)
Configure systemd to keep a TCP port open at all times while starting the backing service process only when the first connection arrives.
Challenges
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.
Make One Echo Server Work with Both TCP and Unix Sockets
Make a single echo server listen on either a TCP socket or a Unix domain socket, selected by its command-line argument. The challenge illustrates that the same stream-socket workflow works with two address families (AF_INET and AF_UNIX).
Submissions: 32/57
Write a TCP Client for a Chat Server
Write a TCP client to hold a back-and-forth conversation with a "chat" server: send a line, read the reply, send another line - repeat until the session is over. A hands-on lesson in designing an application protocol on top of a byte-oriented TCP stream.
Write a TCP Client for a Telemetry Server
Write your first TCP client for a push-only telemetry server that starts sending sensor readings as soon as you connect. Likely the easiest way to get started with TCP socket programming.
Write a TCP Echo Server From Scratch
The Hello World of network programming: implement a tiny TCP echo server in the language of your choice.
Classic Sysadmin Task: Which Port Is a Service Listening On?
Test your Linux and Networking skills by identifying which port a service is using. Sounds easy? Perhaps, but be careful - you only get one shot!
Submissions: 772/1227
Classic Sysadmin Task: Which Process Is Listening on a Port?
Test your Linux and Networking skills by pinpointing a process that is listening on a given port. Sounds easy? Perhaps, but be careful - you only get one shot!
Submissions: 784/1053