improve: add connector advertise addr

internal/connector/connector.go

@@ -12,6 +12,7 @@ import (
 	"net/http"
 	"net/http/httputil"
 	"os"
+	"strconv"
 	"strings"
 	"time"
 
@@ -31,11 +32,12 @@ import (
 )
 
 type Options struct {
-	Server ServerOptions
-	Name   string
-	CACert string // TODO: types.StringOrFile
-	CAKey  string // TODO: types.StringOrFile
-	Addr   string
+	Server        ServerOptions
+	Name          string
+	CACert        string // TODO: types.StringOrFile
+	CAKey         string // TODO: types.StringOrFile
+	Addr          string
+	AdvertiseAddr string
 }
 
 type ServerOptions struct {
@@ -93,7 +95,8 @@ func Run(ctx context.Context, options Options) error {
 	}
 
 	// server is localhost which should never be the case. try to infer the actual host
-	if strings.HasPrefix(u.Host, "localhost") {
+	// TODO: document this change
+	if u.Host == "" {
 		server, err := k8s.Service("server")
 		if err != nil {
 			logging.Warnf("no cluster-local infra server found for %q. check connector configurations", u.Host)
@@ -138,7 +141,7 @@ func Run(ctx context.Context, options Options) error {
 	ctx, cancel := context.WithCancel(ctx)
 	defer cancel()
 
-	repeat.Start(ctx, 5*time.Second, syncWithServer(k8s, client, destination, certCache, caCertPEM))
+	repeat.Start(ctx, 5*time.Second, syncWithServer(k8s, client, destination, certCache, caCertPEM, options))
 
 	ginutil.SetMode()
 	router := gin.New()
@@ -220,13 +223,35 @@ func httpTransportFromOptions(opts ServerOptions) *http.Transport {
 	return transport
 }
 
-func syncWithServer(k8s *kubernetes.Kubernetes, client *api.Client, destination *api.Destination, certCache *CertCache, caCertPEM []byte) func(context.Context) {
-
+func syncWithServer(
+	k8s *kubernetes.Kubernetes,
+	client *api.Client,
+	destination *api.Destination,
+	certCache *CertCache,
+	caCertPEM []byte,
+	opts Options,
+) func(context.Context) {
 	return func(context.Context) {
-		host, port, err := k8s.Endpoint()
-		if err != nil {
-			logging.Errorf("failed to lookup endpoint: %v", err)
-			return
+		var host string
+		var port string
+		var err error
+
+		if opts.AdvertiseAddr != "" {
+			host, port, err = net.SplitHostPort(opts.AdvertiseAddr)
+			if err != nil {
+				// TODO: validate this before the background goroutine starts
+				logging.Errorf("bad advertise addr: %v", err)
+				return
+			}
+		} else {
+			// TODO: cleanup port arg
+			var intPort int
+			host, intPort, err = k8s.Endpoint()
+			if err != nil {
+				logging.Errorf("failed to lookup endpoint: %v", err)
+				return
+			}
+			port = strconv.Itoa(intPort)
 		}
 
 		if ipv4 := net.ParseIP(host); ipv4 == nil {
@@ -244,7 +269,7 @@ func syncWithServer(k8s *kubernetes.Kubernetes, client *api.Client, destination
 			return
 		}
 
-		endpoint := fmt.Sprintf("%s:%d", host, port)
+		endpoint := fmt.Sprintf("%s:%v", host, port)
 		logging.Debugf("connector serving on %s", endpoint)
 
 		namespaces, err := k8s.Namespaces()