api.service.NetworkUtility

This service implements methods currently used to derive information on an incoming request to be exposed in context of code handling the request.

Methods

parseKeyValueHeader()

This method takes the value of a single request header assumed to contain additional information as a sequence of key-value assignments. It returns those named values.

Hitchy's core is using this method to inspect an incoming request's Forwarded header. The resulting information is used as second argument on invoking the additional methods extractClientIp() and compileRequestUrl() to provide this.url and this.clientIp in context of that request's handlers.

extractClientIp()

This method tries to extract the requesting client's IP address from the first of these sources checked in this order:

• the for= part of Forwarded request header
• the X-Forwarded-For request header
• the X-Real-Ip request header
• the address of requesting peer's socket

Advise: properly configure reverse proxies

Because of the potential forwarding of requests by involved proxies, the resulting URL is always a guess, only.

For best results, any involved reverse proxy should properly insert the Forwarded request header.

The method is invoked with these arguments:

• the descriptor of currently processed incoming request
• the result of parsing some Forwarded request header included with that request using method parseKeyValueHeader()

The method is invoked early on every incoming request to expose the resulting address as this.clientIp available in code handling either request.

compileRequestUrl()

This method tries to compile the absolute URL of current request as used by the client.

The resulting URL's

• scheme is derived from the first of these sources:
  • the proto= part of Forwarded request header
  • the X-Forwarded-Proto request header
  • https:// if the request's socket has been marked as encrypted
  • http:// if neither of the previous sources yielded any result
• hostname is retrieved from the first of these sources:
  • the host= part of Forwarded request header
  • the value of Host request header
• pathname is identical to the value of given request's pathname.

Advise: properly configure reverse proxies

Because of the potential forwarding of requests by involved proxies, the resulting URL is always a guess, only.

For best results, any involved reverse proxy should properly insert the Forwarded request header.

The method is invoked with these arguments:

• the descriptor of currently processed incoming request
• the result of parsing some Forwarded request header included with that request using method parseKeyValueHeader()

The method returns an instance of URL.

Hitchy is invoking this method early on every incoming request to expose the returned URL as this.url.