debug: add a unique agic identifier suffix to ARM user agent (#1082)

* debug: add a unique agic identifier

* fix

* change to klog

cmd/appgw-ingress/main.go

@@ -34,6 +34,7 @@ import (
 	"github.com/Azure/application-gateway-kubernetes-ingress/pkg/httpserver"
 	"github.com/Azure/application-gateway-kubernetes-ingress/pkg/k8scontext"
 	"github.com/Azure/application-gateway-kubernetes-ingress/pkg/metricstore"
+	"github.com/Azure/application-gateway-kubernetes-ingress/pkg/utils"
 	"github.com/Azure/application-gateway-kubernetes-ingress/pkg/version"
 )
 
@@ -109,7 +110,13 @@ func main() {
 		klog.Fatal(errorLine)
 	}
 
-	azClient := azure.NewAzClient(azure.SubscriptionID(env.SubscriptionID), azure.ResourceGroup(env.ResourceGroupName), azure.ResourceName(env.AppGwName), env.ClientID)
+	uniqueUserAgentSuffix := utils.RandStringRunes(10)
+	if agicPod != nil {
+		uniqueUserAgentSuffix = agicPod.Name
+	}
+	klog.Infof("Using User Agent Suffix='%s' when communicating with ARM", uniqueUserAgentSuffix)
+
+	azClient := azure.NewAzClient(azure.SubscriptionID(env.SubscriptionID), azure.ResourceGroup(env.ResourceGroupName), azure.ResourceName(env.AppGwName), uniqueUserAgentSuffix, env.ClientID)
 	appGwIdentifier := appgw.Identifier{
 		SubscriptionID: env.SubscriptionID,
 		ResourceGroup:  env.ResourceGroupName,

pkg/azure/client.go

@@ -54,13 +54,13 @@ type azClient struct {
 }
 
 // NewAzClient returns an Azure Client
-func NewAzClient(subscriptionID SubscriptionID, resourceGroupName ResourceGroup, appGwName ResourceName, clientID string) AzClient {
+func NewAzClient(subscriptionID SubscriptionID, resourceGroupName ResourceGroup, appGwName ResourceName, uniqueUserAgentSuffix, clientID string) AzClient {
 	settings, err := auth.GetSettingsFromEnvironment()
 	if err != nil {
 		return nil
 	}
 
-	userAgent := fmt.Sprintf("ingress-appgw/%s", version.Version)
+	userAgent := fmt.Sprintf("ingress-appgw/%s/%s", version.Version, uniqueUserAgentSuffix)
 	az := &azClient{
 		appGatewaysClient:     n.NewApplicationGatewaysClientWithBaseURI(settings.Environment.ResourceManagerEndpoint, string(subscriptionID)),
 		publicIPsClient:       n.NewPublicIPAddressesClientWithBaseURI(settings.Environment.ResourceManagerEndpoint, string(subscriptionID)),

pkg/utils/utils.go

@@ -10,11 +10,19 @@ import (
 	"encoding/json"
 	"fmt"
 	"io/ioutil"
+	"math/rand"
 	"strings"
+	"time"
 
 	"k8s.io/klog/v2"
 )
 
+func init() {
+	rand.Seed(time.Now().UnixNano())
+}
+
+var letterRunes = []rune("abcdefghijklmnopqrstuvwxyz0123456789")
+
 // GetResourceKey generates the key in k8s format for a given resource
 func GetResourceKey(namespace, name string) string {
 	return fmt.Sprintf("%v/%v", namespace, name)
@@ -61,3 +69,12 @@ func GetHashCode(i interface{}) string {
 	}
 	return fmt.Sprintf("%x", md5.Sum(jsonBytes))
 }
+
+// RandStringRunes generates n length random string
+func RandStringRunes(n int) string {
+	b := make([]rune, n)
+	for i := range b {
+		b[i] = letterRunes[rand.Intn(len(letterRunes))]
+	}
+	return string(b)
+}

pkg/utils/utils_test.go

@@ -62,5 +62,15 @@ var _ = Describe("Utils", func() {
 				Expect(hashcode).To(Equal("28a37ff7b783ffb4696dfb7774331163"))
 			})
 		})
+
+		Context("Test RandStringRunes", func() {
+			It("should generate n length string", func() {
+				Expect(len(RandStringRunes(10))).To(Equal(10))
+			})
+
+			It("should not fail when n = 0", func() {
+				Expect(len(RandStringRunes(0))).To(Equal(0))
+			})
+		})
 	})
 })