class Falcon::Middleware::Proxy
A HTTP middleware for proxying requests to a given set of hosts. Typically used for implementing virtual servers.
Constants
- CONNECTION
- FORWARDED
- HOP_HEADERS
HTTP hop headers which should not be passed through the proxy.
- VIA
- X_FORWARDED_FOR
- X_FORWARDED_PROTO
Attributes
The number of requests that have been proxied. @attribute [Integer]
Public Class Methods
Initialize the proxy middleware. @parameter app [Protocol::HTTP::Middleware] The middleware to use if a request can't be proxied. @parameter hosts [Array(Service::Proxy
)] The host applications to proxy to.
# File lib/falcon/middleware/proxy.rb, line 62 def initialize(app, hosts) super(app) @server_context = nil @hosts = hosts @clients = {} @count = 0 end
Public Instance Methods
Proxy
the request if the authority matches a specific host. @parameter request [Protocol::HTTP::Request]
# File lib/falcon/middleware/proxy.rb, line 148 def call(request) if host = lookup(request) @count += 1 request = self.prepare_request(request, host) client = connect(host.endpoint) client.call(request) else super end rescue Console.logger.error(self) {$!} return Protocol::HTTP::Response[502, {'content-type' => 'text/plain'}, ["#{$!.inspect}: #{$!.backtrace.join("\n")}"]] end
Close all the connections to the upstream hosts.
# File lib/falcon/middleware/proxy.rb, line 78 def close @clients.each_value(&:close) super end
Establish a connection to the specified upstream endpoint. @parameter endpoint [Async::HTTP::Endpoint]
# File lib/falcon/middleware/proxy.rb, line 86 def connect(endpoint) @clients[endpoint] ||= Async::HTTP::Client.new(endpoint) end
Lookup the appropriate host for the given request. @parameter request [Protocol::HTTP::Request] @returns [Service::Proxy]
# File lib/falcon/middleware/proxy.rb, line 93 def lookup(request) # Trailing dot and port is ignored/normalized. if authority = request.authority&.sub(/(\.)?(:\d+)?$/, '') return @hosts[authority] end end
Prepare the headers to be sent to an upstream host. In particular, we delete all connection and hop headers.
# File lib/falcon/middleware/proxy.rb, line 102 def prepare_headers(headers) if connection = headers[CONNECTION] headers.extract(connection) end headers.extract(HOP_HEADERS) end
Prepare the request to be proxied to the specified host. In particular, we set appropriate {VIA}, {FORWARDED}, {X_FORWARDED_FOR} and {X_FORWARDED_PROTO} headers.
# File lib/falcon/middleware/proxy.rb, line 112 def prepare_request(request, host) forwarded = [] Console.logger.debug(self) do |buffer| buffer.puts "Request authority: #{request.authority}" buffer.puts "Host authority: #{host.authority}" buffer.puts "Request: #{request.method} #{request.path} #{request.version}" buffer.puts "Request headers: #{request.headers.inspect}" end # The authority of the request must match the authority of the endpoint we are proxying to, otherwise SNI and other things won't work correctly. request.authority = host.authority if address = request.remote_address request.headers.add(X_FORWARDED_FOR, address.ip_address) forwarded << "for=#{address.ip_address}" end if scheme = request.scheme request.headers.add(X_FORWARDED_PROTO, scheme) forwarded << "proto=#{scheme}" end unless forwarded.empty? request.headers.add(FORWARDED, forwarded.join(';')) end request.headers.add(VIA, "#{request.version} #{self.class}") self.prepare_headers(request.headers) return request end