fix: endpoint url to bypass lookup service if envoy sidecar enabled

EndpointURL returns FQDN:443 as endpoint url even if envoy sidecar enabled.
This MR updates to bypass lookup service if envoy sidecar enabled.

lookup/client.go

@@ -20,6 +20,7 @@ import (
 	"context"
 	"crypto/x509"
 	"encoding/base64"
+	"fmt"
 	"log"
 	"net/url"
 
@@ -119,6 +120,10 @@ func (c *Client) SiteID(ctx context.Context) (string, error) {
 // If the endpoint is found, its TLS certificate is also added to the vim25.Client's trusted host thumbprints.
 // If the Lookup Service is not available, the given path is returned as the default.
 func EndpointURL(ctx context.Context, c *vim25.Client, path string, filter *types.LookupServiceRegistrationFilter) string {
+	// Services running on vCenter can bypass lookup service.
+	if useSidecar := internal.UsingEnvoySidecar(c); useSidecar {
+		return fmt.Sprintf("http://%s%s", c.URL().Host, path)
+	}
 	if lu, err := NewClient(ctx, c); err == nil {
 		info, _ := lu.List(ctx, filter)
 		if len(info) != 0 && len(info[0].ServiceEndpoints) != 0 {

lookup/client_test.go

@@ -20,11 +20,16 @@ package lookup_test
 
 import (
 	"context"
+	"fmt"
 	"net/http"
 	"net/url"
+	"os"
 	"strings"
 	"testing"
 
+	"github.com/stretchr/testify/require"
+
+	"github.com/vmware/govmomi/lookup"
 	"github.com/vmware/govmomi/simulator"
 	"github.com/vmware/govmomi/ssoadmin"
 	"github.com/vmware/govmomi/sts"
@@ -69,7 +74,6 @@ func TestEndpointURL(t *testing.T) {
 			}
 		}
 	})
-
 	// these client calls should not fail
 	simulator.Test(func(ctx context.Context, vc *vim25.Client) {
 		{
@@ -96,4 +100,19 @@ func TestEndpointURL(t *testing.T) {
 			}
 		}
 	})
+
+	t.Run("With Envoy sidecar and a malfunctioning lookup service, endpoint url should still succeed", func(t *testing.T) {
+		model := simulator.VPX()
+		model.Create()
+		simulator.Test(func(ctx context.Context, vc *vim25.Client) {
+			lsim.BreakLookupServiceURLs()
+			// Map Envoy sidecar on the same port as the vcsim client.
+			os.Setenv("GOVMOMI_ENVOY_SIDECAR_PORT", vc.Client.URL().Port())
+			os.Setenv("GOVMOMI_ENVOY_SIDECAR_HOST", vc.Client.URL().Hostname())
+			testPath := "/fake/path"
+			expectedUrl := fmt.Sprintf("http://%s%s", vc.Client.URL().Host, testPath)
+			url := lookup.EndpointURL(ctx, vc, testPath, nil)
+			require.Equal(t, expectedUrl, url)
+		}, model)
+	})
 }