making endpoint configurable, attempt to extract host

Author: ramiro-gamarra

cns/configuration/cns_config.json

@@ -18,5 +18,6 @@
     "UseHTTPS" : false,
     "TLSSubjectName" : "",
     "TLSCertificatePath" : "",
-    "TLSEndpoint" : "localhost:10091"
+    "TLSEndpoint" : "localhost:10091",
+    "WireserverIP": "168.63.129.16"
 }

cns/configuration/configuration.go

@@ -24,6 +24,7 @@ type CNSConfig struct {
 	TLSSubjectName     string
 	TLSCertificatePath string
 	TLSEndpoint        string
+	WireserverIP       string
 }
 
 type TelemetrySettings struct {

cns/restserver/api.go

@@ -8,6 +8,7 @@ import (
 	"io/ioutil"
 	"net"
 	"net/http"
+	"regexp"
 	"runtime"
 	"strings"
 
@@ -1139,6 +1140,16 @@ func getAuthTokenFromCreateNetworkContainerURL(
 	return strings.Split(strings.Split(createNetworkContainerURL, "authenticationToken/")[1], "/")[0]
 }
 
+var rgx = regexp.MustCompile("^http[s]?://(.*?)/joinedVirtualNetworks.*?$")
+
+func extractHostFromJoinNetworkURL(url string) string {
+	submatches := rgx.FindStringSubmatch(url)
+	if len(submatches) != 2 {
+		return ""
+	}
+	return submatches[1]
+}
+
 // Publish Network Container by calling nmagent
 func (service *HTTPRestService) publishNetworkContainer(w http.ResponseWriter, r *http.Request) {
 	logger.Printf("[Azure-CNS] PublishNetworkContainer")
@@ -1199,8 +1210,15 @@ func (service *HTTPRestService) publishNetworkContainer(w http.ResponseWriter, r
 		// Store ncGetVersionURL needed for calling NMAgent to check if vfp programming is completed for the NC
 		primaryInterfaceIdentifier := getInterfaceIdFromCreateNetworkContainerURL(req.CreateNetworkContainerURL)
 		authToken := getAuthTokenFromCreateNetworkContainerURL(req.CreateNetworkContainerURL)
+
+		// we attempt to extract the wireserver IP to use from the request, otherwise default to the well-known IP.
+		hostIP := extractHostFromJoinNetworkURL(req.JoinNetworkURL)
+		if hostIP == "" {
+			hostIP = nmagentclient.WireserverIP
+		}
+
 		ncGetVersionURL := fmt.Sprintf(nmagentclient.GetNetworkContainerVersionURLFmt,
-			nmagentclient.WireserverIP,
+			hostIP,
 			primaryInterfaceIdentifier,
 			req.NetworkContainerID,
 			authToken)

cns/restserver/api_test.go

@@ -553,6 +553,16 @@ func publishNCViaCNS(t *testing.T,
 	fmt.Printf("PublishNetworkContainer succeded with response %+v, raw:%+v\n", resp, w.Body)
 }
 
+func TestExtractHost(t *testing.T) {
+	joinURL := "http://127.0.0.1:9001/joinedVirtualNetworks/c9b8e695-2de1-11eb-bf54-000d3af666c8/api-version/1"
+
+	host := extractHostFromJoinNetworkURL(joinURL)
+	expected := "127.0.0.1:9001"
+	if host != expected {
+		t.Fatalf("expected host %q, got %q", expected, host)
+	}
+}
+
 func TestUnpublishNCViaCNS(t *testing.T) {
 	fmt.Println("Test: unpublishNetworkContainer")
 

cns/service/main.go

@@ -404,6 +404,10 @@ func main() {
 	configuration.SetCNSConfigDefaults(&cnsconfig)
 	logger.Printf("[Azure CNS] Read config :%+v", cnsconfig)
 
+	if cnsconfig.WireserverIP != "" {
+		nmagentclient.WireserverIP = cnsconfig.WireserverIP
+	}
+
 	if cnsconfig.ChannelMode == cns.Managed {
 		config.ChannelMode = cns.Managed
 		privateEndpoint = cnsconfig.ManagedSettings.PrivateEndpoint