[http_proxy_over_p2p] httputil.ReverseProxy

Reimplement http-request proxying ala httputil.ReverseProxy.

NB: this is proxies the request synchronously (sends all request-body
before reading any response).

License: MIT
Signed-off-by: Chris Boddy <chris@boddy.im>

core/corehttp/proxy.go

@@ -5,16 +5,17 @@ import (
 	"fmt"
 	"net"
 	"net/http"
-	//"net/http/httputil"
+	"net/http/httputil"
 	"strings"
 
 	core "github.com/ipfs/go-ipfs/core"
 
 	protocol "gx/ipfs/QmZNkThpqfVXs9GNbexPrfBbXSLNYeKrE7jwFM2oqHbyqN/go-libp2p-protocol"
 	peer "gx/ipfs/QmbNepETomvmXfz1X5pHNFD2QuPqnqi47dTd94QJWSorQ3/go-libp2p-peer"
+	inet "gx/ipfs/QmfDPh144WGBqRxZb1TGDHerbMnZATrHZggAPw7putNnBq/go-libp2p-net"
 )
 
-// This adds an endpoint for proxying a request to another ipfs peer
+// This adds an endpoint for proxying a HTTP request to another ipfs peer
 func ProxyOption() ServeOption {
 	return func(ipfsNode *core.IpfsNode, _ net.Listener, mux *http.ServeMux) (*http.ServeMux, error) {
 		mux.HandleFunc("/proxy/http/", func(w http.ResponseWriter, request *http.Request) {
@@ -33,28 +34,7 @@ func ProxyOption() ServeOption {
 				return
 			}
 
-			//httputil.ReverseProxy(
-			// send request to peer
-			proxyReq, err := http.NewRequest(request.Method, parsedRequest.httpPath, request.Body)
-
-			if err != nil {
-				handleError(w, "Failed to format proxy request", err, 500)
-				return
-			}
-
-			proxyReq.Write(stream)
-
-			s := bufio.NewReader(stream)
-			proxyResponse, err := http.ReadResponse(s, proxyReq)
-
-			defer func() { proxyResponse.Body.Close() }()
-			if err != nil {
-				msg := fmt.Sprintf("Failed to send request to stream '%v' to peer '%v'", parsedRequest.name, parsedRequest.target)
-				handleError(w, msg, err, 500)
-				return
-			}
-			// send client response
-			proxyResponse.Write(w)
+			newReverseHttpProxy(parsedRequest, &stream).ServeHTTP(w, request)
 		})
 		return mux, nil
 	}
@@ -85,9 +65,28 @@ func parseRequest(request *http.Request) (*proxyRequest, error) {
 	return &proxyRequest{peerID, split[4], split[5]}, nil
 }
 
-// log error and send response to client
 func handleError(w http.ResponseWriter, msg string, err error, code int) {
 	w.WriteHeader(code)
 	fmt.Fprintf(w, "%s: %s\n", msg, err)
 	log.Warningf("server error: %s: %s", err)
 }
+
+func newReverseHttpProxy(req *proxyRequest, streamToPeer *inet.Stream) *httputil.ReverseProxy {
+	director := func(r *http.Request) {
+		r.URL.Path = req.httpPath //the scheme etc. doesn't matter
+	}
+
+	return &httputil.ReverseProxy{
+		Director:  director,
+		Transport: &roundTripper{streamToPeer}}
+}
+
+type roundTripper struct {
+	stream *inet.Stream
+}
+
+func (self *roundTripper) RoundTrip(req *http.Request) (*http.Response, error) {
+	req.Write(*self.stream)
+	s := bufio.NewReader(*self.stream)
+	return http.ReadResponse(s, req)
+}

test/sharness/t0184-http-proxy-over-p2p.sh

@@ -55,6 +55,9 @@ function setup_sender_ipfs() {
     sleep 5
 }
 
+function setup_sender_and_receiver_ipfs() {
+    setup_receiver_ipfs && setup_sender_ipfs
+}
 
 function teardown_sender_and_receiver() {
     kill -9 $SENDER_PID $RECEIVER_PID > /dev/null 2>&1
@@ -64,9 +67,9 @@ function teardown_sender_and_receiver() {
 function curl_check_response_code() {
     local expected_status_code=$1
     local path_stub=${2:-http/$RECEIVER_ID/test/index.txt}
-    local status_code=$(curl -s --write-out %{http_code} --output /dev/null http://localhost:5001/proxy/$path_stub)
+    local status_code=$(curl -s --write-out %{http_code} --output /dev/null http://localhost:5001/proxy/http/$path_stub)
 
-    if [[ $status_code -ne $expected_status_code ]];
+    if [[ "$status_code" -ne "$expected_status_code" ]];
     then
         echo "Found status-code "$status_code", expected "$expected_status_code
         return 1
@@ -108,44 +111,35 @@ function curl_send_proxy_request_and_check_response() {
 }
 
 
-#test_expect_success 'handle proxy http request propogates error response from remote' '
-#serve_http_once "SORRY GUYS, I LOST IT" "404 Not Found" &&
-#setup_receiver_ipfs &&
-#setup_sender_ipfs &&
-#curl_send_proxy_request_and_check_response 404 "SORRY GUYS, I LOST IT"
-#'
-#kill -9 $REMOTE_SERVER_PID
-#teardown_sender_and_receiver
+test_expect_success 'handle proxy http request propogates error response from remote' '
+serve_http_once "SORRY GUYS, I LOST IT" "404 Not Found" &&
+setup_sender_and_receiver_ipfs &&
+curl_send_proxy_request_and_check_response 404 "SORRY GUYS, I LOST IT"
+'
+teardown_sender_and_receiver
 
-test_expect_success 'handle proxy http request when remote server not available ' '
-setup_receiver_ipfs &&
-setup_sender_ipfs &&
-curl_check_response_code "000"
+test_expect_success 'handle proxy http request sends bad-gateway when remote server not available ' '
+setup_sender_and_receiver_ipfs &&
+curl_send_proxy_request_and_check_response 502 ""
 '
 teardown_sender_and_receiver
 
 test_expect_success 'handle proxy http request ' '
 serve_http_once "THE WOODS ARE LOVELY DARK AND DEEP" &&
-setup_receiver_ipfs &&
-setup_sender_ipfs &&
+setup_sender_and_receiver_ipfs &&
 curl_send_proxy_request_and_check_response 200 "THE WOODS ARE LOVELY DARK AND DEEP"
 '
-kill -9 $REMOTE_SERVER_PID
 teardown_sender_and_receiver
 
-
-
 test_expect_success 'handle proxy http request invalid request' '
-setup_receiver_ipfs &&
-setup_sender_ipfs &&
-curl_check_response_code 404 DERPDERPDERP
+setup_sender_and_receiver_ipfs &&
+curl_check_response_code 400 DERPDERPDERP
 '
 teardown_sender_and_receiver
 
 test_expect_success 'handle proxy http request unknown proxy peer ' '
-setup_receiver_ipfs &&
-setup_sender_ipfs &&
-curl_check_response_code 400 http/unknown_peer/test/index.txt
+setup_sender_and_receiver_ipfs &&
+curl_check_response_code 400 unknown_peer/test/index.txt
 '
 teardown_sender_and_receiver