build: remove DISABLE_NET_TESTS

Don't use external network during all.bash.

R=r, r2, rh, ality
CC=golang-dev
https://golang.org/cl/4429041

src/pkg/Makefile

@@ -202,11 +202,6 @@ NOTEST+=\
 NOBENCH+=\
 	container/vector\
 
-# Disable tests that depend on an external network.
-ifeq ($(DISABLE_NET_TESTS),1)
-NOTEST+=net syslog
-endif
-
 # Disable tests that windows cannot run yet.
 ifeq ($(GOOS),windows)
 NOTEST+=os/signal    # no signals

src/pkg/net/dialgoogle_test.go

@@ -56,6 +56,11 @@ var googleaddrs = []string{
 }
 
 func TestLookupCNAME(t *testing.T) {
+	if testing.Short() {
+		// Don't use external network.
+		t.Logf("skipping external network test during -short")
+		return
+	}
 	cname, err := LookupCNAME("www.google.com")
 	if cname != "www.l.google.com." || err != nil {
 		t.Errorf(`LookupCNAME("www.google.com.") = %q, %v, want "www.l.google.com.", nil`, cname, err)
@@ -63,6 +68,11 @@ func TestLookupCNAME(t *testing.T) {
 }
 
 func TestDialGoogle(t *testing.T) {
+	if testing.Short() {
+		// Don't use external network.
+		t.Logf("skipping external network test during -short")
+		return
+	}
 	// If no ipv6 tunnel, don't try the last address.
 	if !*ipv6 {
 		googleaddrs[len(googleaddrs)-1] = ""

src/pkg/syslog/syslog_test.go

@@ -52,6 +52,10 @@ func TestNewLogger(t *testing.T) {
 }
 
 func TestDial(t *testing.T) {
+	if testing.Short() {
+		// Depends on syslog daemon running, and sometimes it's not.
+		t.Logf("skipping syslog test during -short")
+	}
 	l, err := Dial("", "", LOG_ERR, "syslog_test")
 	if err != nil {
 		t.Fatalf("Dial() failed: %s", err)