only check for availability for IMDS

autorest/adal/token.go

@@ -1317,28 +1317,25 @@ func NewMultiTenantServicePrincipalTokenFromCertificate(multiTenantCfg MultiTena
 
 // MSIAvailable returns true if the MSI endpoint is available for authentication.
 func MSIAvailable(ctx context.Context, s Sender) bool {
-	_, _, err := getMSIAvailable(ctx, s)
-	return err == nil
-}
+	msiType, _, err := getMSIType()
 
-// getMSIAvailable returns the response from the resolved MSI endpoint, the MSI endpoint used, and the error returned
-func getMSIAvailable(ctx context.Context, s Sender) (*http.Response, string, error) {
-	if s == nil {
-		s = sender()
-	}
-	msiType, endpoint, err := getMSIType()
 	if err != nil {
-		return nil, endpoint, err
+		return false
 	}
 
-	var apiVersion string
-	if apiVersion = msiAPIVersion; msiType == msiTypeAppServiceV20170901 {
-		apiVersion = appServiceAPIVersion2017
+	if msiType != msiTypeIMDS {
+		return true
 	}
 
-	resp, err := getMSIEndpoint(ctx, s, endpoint, apiVersion)
+	if s == nil {
+		s = sender()
+	}
+
+	resp, err := getMSIEndpoint(ctx, s)
+
 	if err == nil {
 		resp.Body.Close()
 	}
-	return resp, endpoint, err
+
+	return err == nil
 }

autorest/adal/token_1.13.go

@@ -24,13 +24,13 @@ import (
 	"time"
 )
 
-func getMSIEndpoint(ctx context.Context, sender Sender, endpoint string, apiVersion string) (*http.Response, error) {
+func getMSIEndpoint(ctx context.Context, sender Sender) (*http.Response, error) {
 	tempCtx, cancel := context.WithTimeout(ctx, 2*time.Second)
 	defer cancel()
 	// http.NewRequestWithContext() was added in Go 1.13
-	req, _ := http.NewRequestWithContext(tempCtx, http.MethodGet, endpoint, nil)
+	req, _ := http.NewRequestWithContext(tempCtx, http.MethodGet, msiEndpoint, nil)
 	q := req.URL.Query()
-	q.Add("api-version", apiVersion)
+	q.Add("api-version", msiAPIVersion)
 	req.URL.RawQuery = q.Encode()
 	return sender.Do(req)
 }

autorest/adal/token_test.go

@@ -1352,28 +1352,20 @@ func TestMSIAvailableAppService(t *testing.T) {
 	}()
 	c := mocks.NewSender()
 	c.AppendResponse(mocks.NewResponse())
-	_, endpoint, err := getMSIAvailable(context.Background(), c)
+	available := MSIAvailable(context.Background(), c)
 
-	if err != nil {
-		t.Fatal("unexpected error")
-	}
-
-	if endpoint != "http://localhost" {
-		t.Fatal("incorrect endpoint returned")
+	if !available {
+		t.Fatal("expected MSI to be available")
 	}
 }
 
 func TestMSIAvailableIMDS(t *testing.T) {
 	c := mocks.NewSender()
 	c.AppendResponse(mocks.NewResponse())
-	_, endpoint, err := getMSIAvailable(context.Background(), c)
+	available := MSIAvailable(context.Background(), c)
 
-	if err != nil {
-		t.Fatal("unexpected error")
-	}
-
-	if endpoint != msiEndpoint {
-		t.Fatal("incorrect endpoint returned")
+	if !available {
+		t.Fatal("expected MSI to be available")
 	}
 }
 
@@ -1393,7 +1385,7 @@ func TestMSIAvailableFail(t *testing.T) {
 	if MSIAvailable(context.Background(), c) {
 		t.Fatal("unexpected true")
 	}
-	_, err := getMSIEndpoint(context.Background(), c, msiEndpoint, msiAPIVersion)
+	_, err := getMSIEndpoint(context.Background(), c)
 	if !strings.Contains(err.Error(), "") {
 		t.Fatalf("expected error: '%s', but got error '%s'", expectErr, err)
 	}