The <Advanced routing guide> shows how to add a greedy path matcher to capture the rest of the path ...

# http4k

[Andrew O'Hara]

The Advanced routing guide shows how to add a greedy path matcher to capture the rest of the path after a certain point

"/pattern/{rest:.*}" bind { req: Request -> Response(OK).body(req.path("rest") ?: "") }

I've been unable to replicate this for http4k-contract in a way it will work in a Swagger UI. I've even tried making a lens so it can fit in to the ContractRoute definition, like:

val restLens = Path.regex(".*").of("rest")
val route = "pattern" / restLens

But it just results in a 404.

Has anyone ever gotten this to work with Swagger UI?

[Andrew O'Hara]

Ah, it came to me immediately after posting. This lens works:

val restLens = Path.string().of("rest:.*")

[dave]

wow! I absolutely 100% thought that would not work! Thank you for the lesson! 🤣

[Andrew O'Hara]

Maybe it's entirely coincidental that the implementation allows the greediness. I should maybe add a test to ensure it doesn't get broken by accident.

[Arnab]

Out of curiosity, what's the use case here? It's always interesting to look at the use cases behind these things :)

[Andrew O'Hara]

We've got some old weird proxies that need to be maintained. They're used to communicate to IOT devices that maintain a persistent connection with us.

Instead of setting an HTTP proxy in our requests, I have to maintain a connection format like:

http://<proxy-host>/<device-token>/<target-uri>

where the device-token is used to lookup the IOT device's connection. We get the connection, and then send the device something like

<http://localhost/><target-uri>

In most cases, we're actually communicating a custom TCP protocol, but the HTTP request above illustrates the point.