internal/httpsvc: Join host/port with net helper

Ensures we take an ipv6 address w/o brackets which matches the existing flags

Updates projectcontour#3284

Signed-off-by: Sunjay Bhatia <sunjayb@vmware.com>

cmd/contour/serve.go

@@ -136,7 +136,7 @@ func registerServe(app *kingpin.Application) (*kingpin.CmdClause, *serveContext)
 	serve.Flag("ingress-status-address", "Address to set in Ingress object status.").PlaceHolder("<address>").StringVar(&ctx.Config.IngressStatusAddress)
 	serve.Flag("envoy-http-access-log", "Envoy HTTP access log.").PlaceHolder("/path/to/file").StringVar(&ctx.httpAccessLog)
 	serve.Flag("envoy-https-access-log", "Envoy HTTPS access log.").PlaceHolder("/path/to/file").StringVar(&ctx.httpsAccessLog)
-	serve.Flag("envoy-service-http-address", "Kubernetes Service address for HTTP requests.").PlaceHolder("ipaddr").StringVar(&ctx.httpAddr)
+	serve.Flag("envoy-service-http-address", "Kubernetes Service address for HTTP requests.").PlaceHolder("<ipaddr>").StringVar(&ctx.httpAddr)
 	serve.Flag("envoy-service-https-address", "Kubernetes Service address for HTTPS requests.").PlaceHolder("<ipaddr>").StringVar(&ctx.httpsAddr)
 	serve.Flag("envoy-service-http-port", "Kubernetes Service port for HTTP requests.").PlaceHolder("<port>").IntVar(&ctx.httpPort)
 	serve.Flag("envoy-service-https-port", "Kubernetes Service port for HTTPS requests.").PlaceHolder("<port>").IntVar(&ctx.httpsPort)

internal/httpsvc/http.go

@@ -17,8 +17,9 @@ package httpsvc
 
 import (
 	"context"
-	"fmt"
+	"net"
 	"net/http"
+	"strconv"
 	"time"
 
 	"github.com/sirupsen/logrus"
@@ -45,7 +46,7 @@ func (svc *Service) Start(stop <-chan struct{}) (err error) {
 	}()
 
 	s := http.Server{
-		Addr:           fmt.Sprintf("%s:%d", svc.Addr, svc.Port),
+		Addr:           net.JoinHostPort(svc.Addr, strconv.Itoa(svc.Port)),
 		Handler:        &svc.ServeMux,
 		ReadTimeout:    10 * time.Second,
 		WriteTimeout:   5 * time.Minute, // allow for long trace requests