This function constructs an ID extractor for incoming requests, the return value of which will be passed to the id argument of request, header, message etc handlers. By default, fiery uses this with default arguments.
Details
A session id is looked for in the cookie matching the name
arg. If it is
found then the value of the cookie is returned. If it is not found then an
id is generated with reqres::random_key()
and attached to the response as
a cookie with the given name. The cookie is set to HTTP only and Strict same
site policy. Depending on secure
it also sets it to only be transferred
over HTTPS.