pkg/Makefile: allow DISABLE_NET_TESTS=1 to disable network tests

netchan, rpc, websocket: run test servers on 127.0.0.1,
to avoid conflict with OS X firewall.

TBR=r
CC=golang-dev
https://golang.org/cl/1689046

src/pkg/Makefile

diff --git a/src/pkg/Makefile b/src/pkg/Makefile
index 005c957..1bbb91b 100644
--- a/src/pkg/Makefile
+++ b/src/pkg/Makefile
@@ -146,11 +146,10 @@
 NOBENCH=\
 	container/vector\
 
-TEST=\
-	$(filter-out $(NOTEST),$(DIRS))
-
-BENCH=\
-	$(filter-out $(NOBENCH),$(TEST))
+# Disable tests that depend on an external network.
+ifeq ($(DISABLE_NET_TESTS),1)
+NOTEST+=http net
+endif
 
 # Disable tests that NaCl cannot run yet.
 ifeq ($(GOOS),nacl)
@@ -172,6 +171,12 @@
 NOTEST+=websocket    # no network
 endif
 
+TEST=\
+	$(filter-out $(NOTEST),$(DIRS))
+
+BENCH=\
+	$(filter-out $(NOBENCH),$(TEST))
+
 clean.dirs: $(addsuffix .clean, $(DIRS))
 install.dirs: $(addsuffix .install, $(DIRS))
 nuke.dirs: $(addsuffix .nuke, $(DIRS))

src/pkg/netchan/netchan_test.go

diff --git a/src/pkg/netchan/netchan_test.go b/src/pkg/netchan/netchan_test.go
index ca3f4d4..01fc0f3 100644
--- a/src/pkg/netchan/netchan_test.go
+++ b/src/pkg/netchan/netchan_test.go
@@ -72,7 +72,7 @@
 }
 
 func TestExportSendImportReceive(t *testing.T) {
-	exp, err := NewExporter("tcp", ":0")
+	exp, err := NewExporter("tcp", "127.0.0.1:0")
 	if err != nil {
 		t.Fatal("new exporter:", err)
 	}
@@ -85,7 +85,7 @@
 }
 
 func TestExportReceiveImportSend(t *testing.T) {
-	exp, err := NewExporter("tcp", ":0")
+	exp, err := NewExporter("tcp", "127.0.0.1:0")
 	if err != nil {
 		t.Fatal("new exporter:", err)
 	}
@@ -98,7 +98,7 @@
 }
 
 func TestClosingExportSendImportReceive(t *testing.T) {
-	exp, err := NewExporter("tcp", ":0")
+	exp, err := NewExporter("tcp", "127.0.0.1:0")
 	if err != nil {
 		t.Fatal("new exporter:", err)
 	}

src/pkg/rpc/server_test.go

diff --git a/src/pkg/rpc/server_test.go b/src/pkg/rpc/server_test.go
index 3196891..edf35e6 100644
--- a/src/pkg/rpc/server_test.go
+++ b/src/pkg/rpc/server_test.go
@@ -55,7 +55,7 @@
 func startServer() {
 	Register(new(Arith))
 
-	l, e := net.Listen("tcp", ":0") // any available address
+	l, e := net.Listen("tcp", "127.0.0.1:0") // any available address
 	if e != nil {
 		log.Exitf("net.Listen tcp :0: %v", e)
 	}
@@ -64,7 +64,7 @@
 	go Accept(l)
 
 	HandleHTTP()
-	l, e = net.Listen("tcp", ":0") // any available address
+	l, e = net.Listen("tcp", "127.0.0.1:0") // any available address
 	if e != nil {
 		log.Stderrf("net.Listen tcp :0: %v", e)
 		os.Exit(1)

src/pkg/websocket/websocket_test.go

diff --git a/src/pkg/websocket/websocket_test.go b/src/pkg/websocket/websocket_test.go
index 0762fca..df7e9f4 100644
--- a/src/pkg/websocket/websocket_test.go
+++ b/src/pkg/websocket/websocket_test.go
@@ -20,7 +20,7 @@
 func echoServer(ws *Conn) { io.Copy(ws, ws) }
 
 func startServer() {
-	l, e := net.Listen("tcp", ":0") // any available address
+	l, e := net.Listen("tcp", "127.0.0.1:0") // any available address
 	if e != nil {
 		log.Exitf("net.Listen tcp :0 %v", e)
 	}