From 9f219badab92cb3d018d7945b04177680767d258 Mon Sep 17 00:00:00 2001
From: Alfonso Acosta <fons@weave.works>
Date: Sun, 10 Apr 2016 01:36:52 +0000
Subject: [PATCH] Stop using the httputil client for plugins

* It sends unexpected TCP RSTs (causing connection reset by peer errors in the python plugin)

  Exception happened during processing of request from
  Traceback (most recent call last):
    File "/usr/lib/python2.7/SocketServer.py", line 295, in _handle_request_noblock
      self.process_request(request, client_address)
    File "/usr/lib/python2.7/SocketServer.py", line 321, in process_request
      self.finish_request(request, client_address)
    File "./http-requests.py", line 145, in finish_request
      self.RequestHandlerClass(request, '-', self)
    File "/usr/lib/python2.7/SocketServer.py", line 658, in __init__
      self.handle()
    File "/usr/lib/python2.7/BaseHTTPServer.py", line 349, in handle
      self.handle_one_request()
    File "/usr/lib/python2.7/BaseHTTPServer.py", line 312, in handle_one_request
      self.raw_requestline = self.rfile.readline(65537)
    File "/usr/lib/python2.7/socket.py", line 480, in readline
      data = self._sock.recv(self._rbufsize)
  error: [Errno 104] Connection reset by peer

* It doesn't reuse connections
---
 probe/plugins/registry.go           |  2 +-
 probe/plugins/unix_round_tripper.go | 21 +++++----------------
 2 files changed, 6 insertions(+), 17 deletions(-)

diff --git a/probe/plugins/registry.go b/probe/plugins/registry.go
index 64967024c..fb5f3c5cf 100644
--- a/probe/plugins/registry.go
+++ b/probe/plugins/registry.go
@@ -290,7 +290,7 @@ func (p *Plugin) get(path string, params url.Values, result interface{}) error {
 	// Context here lets us either timeout req. or cancel it in Plugin.Close
 	ctx, cancel := context.WithTimeout(p.context, pluginTimeout)
 	defer cancel()
-	resp, err := ctxhttp.Get(ctx, p.client, fmt.Sprintf("unix://%s?%s", path, params.Encode()))
+	resp, err := ctxhttp.Get(ctx, p.client, fmt.Sprintf("http://plugin%s?%s", path, params.Encode()))
 	if err != nil {
 		return err
 	}
diff --git a/probe/plugins/unix_round_tripper.go b/probe/plugins/unix_round_tripper.go
index 0bbd49b51..1220df9d4 100644
--- a/probe/plugins/unix_round_tripper.go
+++ b/probe/plugins/unix_round_tripper.go
@@ -3,25 +3,14 @@ package plugins
 import (
 	"net"
 	"net/http"
-	"net/http/httputil"
 	"time"
 )
 
-type unixRoundTripper struct {
-	address string
-	timeout time.Duration
-}
-
 func makeUnixRoundTripper(address string, timeout time.Duration) (http.RoundTripper, error) {
-	return unixRoundTripper{address: address, timeout: timeout}, nil
-}
-
-func (t unixRoundTripper) RoundTrip(req *http.Request) (*http.Response, error) {
-	conn, err := net.DialTimeout("unix", t.address, t.timeout)
-	if err != nil {
-		return nil, err
+	rt := &http.Transport{
+		Dial: func(proto, addr string) (conn net.Conn, err error) {
+			return net.DialTimeout("unix", address, timeout)
+		},
 	}
-	client := httputil.NewClientConn(conn, nil)
-	defer client.Close()
-	return client.Do(req)
+	return rt, nil
 }