middleware/proxy: silence gprc errors (#699)

* middleware/proxy: silence gprc errors

Add discard logger

* Silence glog crap

* Revert "Silence glog crap"

This reverts commit a15dafbca6.

middleware/proxy/grpc_test.go

@@ -3,6 +3,8 @@ package proxy
 import (
 	"testing"
 	"time"
+
+	"google.golang.org/grpc/grpclog"
 )
 
 func pool() []*UpstreamHost {
@@ -17,6 +19,8 @@ func pool() []*UpstreamHost {
 }
 
 func TestStartupShutdown(t *testing.T) {
+	grpclog.SetLogger(discard{})
+
 	upstream := &staticUpstream{
 		from:        ".",
 		Hosts:       pool(),
@@ -28,7 +32,7 @@ func TestStartupShutdown(t *testing.T) {
 	g := newGrpcClient(nil, upstream)
 	upstream.ex = g
 
-	p := &Proxy{Trace: nil}
+	p := &Proxy{}
 	p.Upstreams = &[]Upstream{upstream}
 
 	err := g.OnStartup(p)
@@ -52,3 +56,13 @@ func TestStartupShutdown(t *testing.T) {
 		t.Errorf("Shutdown didn't remove conns, found %d", len(g.conns))
 	}
 }
+
+// discard is a Logger that outputs nothing.
+type discard struct{}
+
+func (d discard) Fatal(args ...interface{})                 {}
+func (d discard) Fatalf(format string, args ...interface{}) {}
+func (d discard) Fatalln(args ...interface{})               {}
+func (d discard) Print(args ...interface{})                 {}
+func (d discard) Printf(format string, args ...interface{}) {}
+func (d discard) Println(args ...interface{})               {}