git » dnss » commit 1dfd282

diff --git a/testing/grpc/grpc_test.go b/testing/grpc/grpc_test.go
index 95c3a36..0172b9a 100644
--- a/testing/grpc/grpc_test.go
+++ b/testing/grpc/grpc_test.go
@@ -24,12 +24,15 @@ import (
 	"github.com/miekg/dns"
 )
 
-const (
-	// TODO: Don't hard-code these.
-	dnsToGrpcAddr = "127.0.0.1:13451"
-	grpcToDnsAddr = "127.0.0.1:13452"
-	dnsSrvAddr    = "127.0.0.1:13453"
-)
+// Addresses to use for testing. These will be picked at initialization time,
+// see init().
+var dnsToGrpcAddr, grpcToDnsAddr, dnsSrvAddr string
+
+func init() {
+	dnsToGrpcAddr = util.GetFreePort()
+	grpcToDnsAddr = util.GetFreePort()
+	dnsSrvAddr = util.GetFreePort()
+}
 
 //
 // === Tests ===
diff --git a/testing/https/https_test.go b/testing/https/https_test.go
index 1794d56..b984ea2 100644
--- a/testing/https/https_test.go
+++ b/testing/https/https_test.go
@@ -128,10 +128,8 @@ const jsonNXDOMAIN = ` {
 	  "data": "root. nstld. 2016052201 1800 900 604800 86400" } ] }
 `
 
-const (
-	// TODO: don't hardcode these.
-	DNSAddr string = "127.0.0.1:19251"
-)
+// Address where we will set up the DNS server.
+var DNSAddr string
 
 // realMain is the real main function, which returns the value to pass to
 // os.Exit(). We have to do this so we can use defer.
@@ -139,6 +137,8 @@ func realMain(m *testing.M) int {
 	flag.Parse()
 	defer glog.Flush()
 
+	DNSAddr = util.GetFreePort()
+
 	// Test http server.
 	httpsrv := httptest.NewServer(http.HandlerFunc(DNSHandler))
 
diff --git a/testing/util/util.go b/testing/util/util.go
index 975cef6..c59d72b 100644
--- a/testing/util/util.go
+++ b/testing/util/util.go
@@ -3,6 +3,7 @@ package util
 
 import (
 	"fmt"
+	"net"
 	"testing"
 	"time"
 
@@ -40,6 +41,14 @@ func WaitForDNSServer(addr string) error {
 	return fmt.Errorf("not reachable")
 }
 
+// Get a free (TCP) port. This is hacky and not race-free, but it works well
+// enough for testing purposes.
+func GetFreePort() string {
+	l, _ := net.Listen("tcp", "localhost:0")
+	defer l.Close()
+	return l.Addr().String()
+}
+
 // TestTrace implements the tracer.Trace interface, but prints using the test
 // logging infrastructure.
 type TestTrace struct {