host-based dispatching dispatch rules can now take two different forms: The old form: {PathMatchSpec, Module, Paramters} The new form: {HostMatchSpec, [{PathMatchSpec, Module, Parameters}]} The former is equivalent to the latter with HostMatchSpec={['*'],'*'} HostMatchSpec is matched against one of (in order of preference): X-Forwarded-For, X-Forwarded-Host, X-Forwarded-Server, Host HostMatchSpec can have two forms: {[HostPart], PortSpec} or [HostPart] The latter is equivalent to the former with PortSpec='*' The list of host parts is matched against the hostname extracted from a header in much the same way that PathMatchSpec is matched against the path. Examples: {[], root_resource, [x]}. {['*'], [{[], root_resource, [x]}]}. {{['*'],'*'}, [{[], root_resource, [x]}]}. Will each match the root path of any host. {["example","com"], [{[], root_resource, [x]}, {["static"], static_resource, [y]}]}. Will dispatch the root of example.com to root_resource and example.com/static to static_resource. {['*',"example","com"], [{[], root_resource, [x]}, {["static"], static_resource, [y]}]}. Will do the same as above, but also for any subdomains of example.com. {{[host,"local"], 8000}, [{[], res_A, [x]}]}. {{[host,"local"], 8001}, [{[], res_B, [x]}]}. Will dispatch requests to ?.local:8000/ to res_A and requests to ?.local:8001/ to resB, binding the host part immediately preceeding ".local" to 'host', such that wrq:get_path_info(host, ReqData) would return the matched string. default