From 6fa8f7763841460c1dd2d2b22b5dddd96ac00250 Mon Sep 17 00:00:00 2001
From: Xiang Li <xiang.li@coreos.com>
Date: Mon, 10 Nov 2014 15:56:42 -0800
Subject: [PATCH 1/2] proxy: return JSON errors

---
 proxy/reverse.go      | 15 +++++++++++----
 proxy/reverse_test.go |  4 ++++
 2 files changed, 15 insertions(+), 4 deletions(-)

diff --git a/proxy/reverse.go b/proxy/reverse.go
index 2dfb313f0..e1f9328a1 100644
--- a/proxy/reverse.go
+++ b/proxy/reverse.go
@@ -17,12 +17,15 @@
 package proxy
 
 import (
+	"fmt"
 	"io"
 	"log"
 	"net"
 	"net/http"
 	"net/url"
 	"strings"
+
+	"github.com/coreos/etcd/etcdserver/etcdhttp/httptypes"
 )
 
 // Hop-by-hop headers. These are removed when sent to the backend.
@@ -64,8 +67,10 @@ func (p *reverseProxy) ServeHTTP(rw http.ResponseWriter, clientreq *http.Request
 
 	endpoints := p.director.endpoints()
 	if len(endpoints) == 0 {
-		log.Printf("proxy: zero endpoints currently available")
-		rw.WriteHeader(http.StatusServiceUnavailable)
+		msg := "proxy: zero endpoints currently available"
+		log.Printf(msg)
+		e := httptypes.NewHTTPError(http.StatusServiceUnavailable, msg)
+		e.WriteTo(rw)
 		return
 	}
 
@@ -86,8 +91,10 @@ func (p *reverseProxy) ServeHTTP(rw http.ResponseWriter, clientreq *http.Request
 	}
 
 	if res == nil {
-		log.Printf("proxy: unable to get response from %d endpoint(s)", len(endpoints))
-		rw.WriteHeader(http.StatusBadGateway)
+		msg := fmt.Sprintf("proxy: unable to get response from %d endpoint(s)", len(endpoints))
+		log.Printf(msg)
+		e := httptypes.NewHTTPError(http.StatusBadGateway, msg)
+		e.WriteTo(rw)
 		return
 	}
 
diff --git a/proxy/reverse_test.go b/proxy/reverse_test.go
index 0a74dd8a7..499b8d879 100644
--- a/proxy/reverse_test.go
+++ b/proxy/reverse_test.go
@@ -70,6 +70,7 @@ func TestReverseProxyServe(t *testing.T) {
 				res: &http.Response{
 					StatusCode: http.StatusCreated,
 					Body:       ioutil.NopCloser(&bytes.Reader{}),
+					Header:     map[string][]string{"Content-Type": []string{"application/json"}},
 				},
 			},
 			want: http.StatusCreated,
@@ -89,6 +90,9 @@ func TestReverseProxyServe(t *testing.T) {
 		if rr.Code != tt.want {
 			t.Errorf("#%d: unexpected HTTP status code: want = %d, got = %d", i, tt.want, rr.Code)
 		}
+		if gct := rr.Header().Get("Content-Type"); gct != "application/json" {
+			t.Errorf("#%d: Content-Type = %s, want %s", i, gct, "application/json")
+		}
 	}
 }
 

From 424377f859f6a28083bfe5b0c8eb3baec2b377b9 Mon Sep 17 00:00:00 2001
From: Xiang Li <xiang.li@coreos.com>
Date: Mon, 10 Nov 2014 16:37:15 -0800
Subject: [PATCH 2/2] proxy: add a todo for logging

---
 proxy/reverse.go | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/proxy/reverse.go b/proxy/reverse.go
index e1f9328a1..c9addd2ed 100644
--- a/proxy/reverse.go
+++ b/proxy/reverse.go
@@ -68,6 +68,7 @@ func (p *reverseProxy) ServeHTTP(rw http.ResponseWriter, clientreq *http.Request
 	endpoints := p.director.endpoints()
 	if len(endpoints) == 0 {
 		msg := "proxy: zero endpoints currently available"
+		// TODO: limit the rate of the error logging.
 		log.Printf(msg)
 		e := httptypes.NewHTTPError(http.StatusServiceUnavailable, msg)
 		e.WriteTo(rw)
@@ -91,6 +92,7 @@ func (p *reverseProxy) ServeHTTP(rw http.ResponseWriter, clientreq *http.Request
 	}
 
 	if res == nil {
+		// TODO: limit the rate of the error logging.
 		msg := fmt.Sprintf("proxy: unable to get response from %d endpoint(s)", len(endpoints))
 		log.Printf(msg)
 		e := httptypes.NewHTTPError(http.StatusBadGateway, msg)