Correct way to get request host?

[alexgleason]

Hi, I know I can route by host. But I want to create an endpoint for any host, and then return dynamically based on the host.

So what I want to know is, should I check req.header('host')? Or should I check new URL(req.url).host? Does hono enforce that these must be the same? Is there any security issues to be aware of?

[alexgleason]

According to the fetch spec, req.headers:

Returns a Headers object consisting of the headers associated with request. Note that headers added in the network layer by the user agent will not be accounted for in this object, e.g., the "Host" header.

Therefore the correct way is to get the host with new URL(req.url).host.

You just need to be sure if you have any reverse-proxy, it's sending the Host header down to your runtime. Using Nginx with Deno, the host is available in the request URL.