Today Thorsten Ball asked a simple question on Twitter:

Does something like a reverse-curl exist? A tool that allows me to listen on a socket and return one HTTP response?

— Thorsten Ball (@thorstenball) October 27, 2017

After a brief exchange of tweets, I said:

Or we could write one in Go 😺

— Lean (inkel) (@inkel) October 27, 2017

Twenty minutes later lruc was born.

Oh wow! :)

— Thorsten Ball (@thorstenball) October 27, 2017

It’s still very fresh and missing many features, but basically it is a web server that allows you to configure it to always respond with a custom response without too much hassle. The usage is very simple:

Usage of lruc:
  -addr string
        Address to listen for requests (default ":8080")
  -body -
        Response body. Use - to read from a stdin (default "Hello, World!")
  -code int
        HTTP response code (default 200)
  -content-type string
        Content-Type (default "text/plain")

Say that you want to create a server that always respond with a 404 Not Found and a body of No se pudo encontrar lo que buscaba (Spanish for Couldn’t find what you were looking for (sort of)) on port 7070, then you could execute the following:

lruc -addr :7070 -code 404 -body "No se pudo encontrar lo que buscaba"

Or say that you want to always return an image, then you could do something like:

< image.png lruc -content-type image/png -body -

# Or in an useless use of cat
cat image.png | lruc -content-type image/png -body -

This seems like an interesting tool to keep working on, so watch github.com/inkel/lruc for updates.

PS: did I said already that I love Go?