Adding a testfiles/ports.go library.

It handles port and zookeeper IDs allocation for tests, so they don't
step on eachothers toes.

go/testfiles/locate.go

@@ -3,6 +3,7 @@
 // license that can be found in the LICENSE file.
 
 // Package testfiles locates test files within the Vitess directory tree.
+// It also handles test port allocation.
 package testfiles
 
 import (
@@ -12,6 +13,7 @@ import (
 	"path/filepath"
 )
 
+// Locate returns a file path that came from $VTROOT/data/test.
 func Locate(filename string) string {
 	vtroot := os.Getenv("VTROOT")
 	if vtroot == "" {
@@ -20,6 +22,7 @@ func Locate(filename string) string {
 	return path.Join(vtroot, "data", "test", filename)
 }
 
+// Glob returns all files matching a pattern in $VTROOT/data/test.
 func Glob(pattern string) []string {
 	vtroot := os.Getenv("VTROOT")
 	if vtroot == "" {

go/testfiles/ports.go

@@ -0,0 +1,65 @@
+package testfiles
+
+import (
+	"fmt"
+	"os"
+	"strconv"
+)
+
+// This file contains helper methods and declarations so all unit
+// tests use different ports.
+//
+// We also use it to allocate Zookeeper server IDs.
+
+//
+// Port definitions. Unit tests may run at the same time,
+// so they should not use the same ports.
+//
+var (
+	// vtPortStart is the starting port for all tests.
+	vtPortStart = getPortStart()
+
+	// GoVtTopoEtcd2topoPort is used by the go/vt/topo/etcd2topo package.
+	// Takes two ports.
+	GoVtTopoEtcd2topoPort = vtPortStart
+
+	// GoVtTopoZk2topoPort is used by the go/vt/topo/zk2topo package.
+	// Takes three ports.
+	GoVtTopoZk2topoPort = GoVtTopoEtcd2topoPort + 2
+
+	// GoVtTabletserverCustomruleZkcustomrulePort is used by the go/vt/tabletserver/customrule/zkcustomrule package.
+	// Takes three ports.
+	GoVtTabletserverCustomruleZkcustomrulePort = GoVtTopoZk2topoPort + 3
+
+	// GoVtZktopoPort is used by the go/vt/zktopo package.
+	// Takes three ports.
+	GoVtZktopoPort = GoVtTabletserverCustomruleZkcustomrulePort + 3
+)
+
+//
+// Zookeeper server ID definitions. Unit tests may run at the
+// same time, so they can't use the same Zookeeper server IDs.
+//
+var (
+	// GoVtTopoZk2topoZk is used by the go/vt/topo/zk2topo package.
+	GoVtTopoZk2topoZk = 1
+
+	// GoVtTabletserverCustomruleZkcustomruleZk is used by the
+	// go/vt/tabletserver/customrule/zkcustomrule package.
+	GoVtTabletserverCustomruleZkcustomruleZk = 2
+
+	// GoVtZktopoZk is used by the go/vt/zktopo package.
+	GoVtZktopoZk = 3
+)
+
+func getPortStart() int {
+	env := os.Getenv("VTPORTSTART")
+	if env == "" {
+		env = "6700"
+	}
+	portStart, err := strconv.Atoi(env)
+	if err != nil {
+		panic(fmt.Errorf("cannot parse VTPORTSTART: %v", err))
+	}
+	return portStart
+}

go/vt/tabletserver/customrule/zkcustomrule/zkcustomrule_test.go

@@ -12,6 +12,7 @@ import (
 
 	"github.com/samuel/go-zookeeper/zk"
 
+	"github.com/youtube/vitess/go/testfiles"
 	"github.com/youtube/vitess/go/vt/tabletserver"
 	"github.com/youtube/vitess/go/vt/tabletserver/tabletservermock"
 	"github.com/youtube/vitess/go/vt/topo/zk2topo"
@@ -43,7 +44,7 @@ var customRule2 = `
 
 func TestZkCustomRule(t *testing.T) {
 	// Start a real single ZK daemon, and close it after all tests are done.
-	zkd, serverAddr := zkctl.StartLocalZk(2)
+	zkd, serverAddr := zkctl.StartLocalZk(testfiles.GoVtTabletserverCustomruleZkcustomruleZk, testfiles.GoVtTabletserverCustomruleZkcustomrulePort)
 	defer zkd.Teardown()
 
 	// Create fake file.

go/vt/topo/etcd2topo/server_test.go

@@ -10,13 +10,13 @@ import (
 	"os"
 	"os/exec"
 	"path"
-	"strconv"
 	"testing"
 	"time"
 
 	"github.com/golang/protobuf/proto"
 	"golang.org/x/net/context"
 
+	"github.com/youtube/vitess/go/testfiles"
 	"github.com/youtube/vitess/go/vt/topo"
 	"github.com/youtube/vitess/go/vt/topo/test"
 
@@ -31,15 +31,8 @@ func startEtcd(t *testing.T) (*exec.Cmd, string, string) {
 		t.Fatalf("cannot create tempdir: %v", err)
 	}
 
-	// Find two ports to listen to. Same logic as the end-to-end tests.
-	env := os.Getenv("VTPORTSTART")
-	if env == "" {
-		env = "6700"
-	}
-	port, err := strconv.Atoi(env)
-	if err != nil {
-		t.Fatalf("cannot parse VTPORTSTART: %v", err)
-	}
+	// Get our two ports to listen to.
+	port := testfiles.GoVtTopoEtcd2topoPort
 	name := "vitess_unit_test"
 	clientAddr := fmt.Sprintf("http://localhost:%v", port)
 	peerAddr := fmt.Sprintf("http://localhost:%v", port+1)

go/vt/topo/zk2topo/server_test.go

@@ -9,6 +9,7 @@ import (
 	"github.com/samuel/go-zookeeper/zk"
 	"golang.org/x/net/context"
 
+	"github.com/youtube/vitess/go/testfiles"
 	"github.com/youtube/vitess/go/vt/topo"
 	"github.com/youtube/vitess/go/vt/topo/test"
 	"github.com/youtube/vitess/go/zk/zkctl"
@@ -18,7 +19,7 @@ import (
 
 func TestZk2Topo(t *testing.T) {
 	// Start a real single ZK daemon, and close it after all tests are done.
-	zkd, serverAddr := zkctl.StartLocalZk(1)
+	zkd, serverAddr := zkctl.StartLocalZk(testfiles.GoVtTopoZk2topoZk, testfiles.GoVtTopoZk2topoPort)
 	defer zkd.Teardown()
 
 	// This function will create a toplevel directory for a new test.

go/vt/zktopo/server_test.go

@@ -11,6 +11,7 @@ import (
 	zookeeper "github.com/samuel/go-zookeeper/zk"
 	"golang.org/x/net/context"
 
+	"github.com/youtube/vitess/go/testfiles"
 	"github.com/youtube/vitess/go/vt/topo"
 	"github.com/youtube/vitess/go/vt/topo/test"
 	"github.com/youtube/vitess/go/zk"
@@ -22,7 +23,7 @@ import (
 // Run the topology test suite on zktopo.
 func TestZkTopo(t *testing.T) {
 	// Start a real single ZK daemon, and close it after all tests are done.
-	zkd, serverAddr := zkctl.StartLocalZk(3)
+	zkd, serverAddr := zkctl.StartLocalZk(testfiles.GoVtZktopoZk, testfiles.GoVtZktopoPort)
 	defer zkd.Teardown()
 
 	// Create a ZK_CLIENT_CONFIG file to use.

go/zk/zkctl/zkctl_local.go

@@ -2,8 +2,6 @@ package zkctl
 
 import (
 	"fmt"
-	"os"
-	"strconv"
 
 	log "github.com/golang/glog"
 
@@ -12,20 +10,9 @@ import (
 
 // StartLocalZk is a helper method to create a local ZK process.  Used
 // in tests, mostly. It will log.Fatal out if there is an error.  Each
-// call should use different serverID, so tests don't interfere with
-// eachother.
-func StartLocalZk(id int) (*Zkd, string) {
-	// Get the starting port.
-	env := os.Getenv("VTPORTSTART")
-	if env == "" {
-		env = "6700"
-	}
-	portStart, err := strconv.Atoi(env)
-	if err != nil {
-		log.Fatalf("cannot parse VTPORTSTART: %v", err)
-	}
-	port := portStart + (id-1)*3
-
+// call should use different serverID / ports, so tests don't
+// interfere with eachother. Use the testfiles package to achieve this.
+func StartLocalZk(id, port int) (*Zkd, string) {
 	// Build the config parameters.
 	hostname := netutil.FullyQualifiedHostnameOrPanic()
 	zkCfg := fmt.Sprintf("%v@%v:%v:%v:%v", id, hostname, port, port+1, port+2)