HTTP Server on random available port in Go

Imagine you want to start an HTTP server without specifying the port. For example, a temporary server for testing. How do you do that? I’ll give you a way to implement this design and a clear understanding of what Go does inside the net package.

Imagine you want to start an HTTP server without specifying the port. For example, a temporary server for testing. How do you do that?

The answer is straightforward. Specify the port number to 0 like:

l, err := net.Listen("tcp", ":0")

It’s an easy rule provided by the net package, but do you understand how Go binds a random port allocation. I’ll give you a clear understanding of what Go does inside the net package.

The presentation contains the following topics.

• net, net/http packages
• File descriptor
• TCP, UDP
• System calls

I think this presentation will give audiences not only a knowledge of Go, but also one of system calls.

The content of this proposal was already published on dev.to.

https://dev.to/hgsgtk/how-go-handles-network-and-system-calls-when-tcp-server-1nbd