Retry if response StatusCode 200 and ContentLength -1

ARM will possibly return StatusCode 200 and ContentLength
-1 which is a bug. However, cloudprovider can handle it
better by retrying.

Signed-off-by: Zhecheng Li <zhechengli@microsoft.com>

pkg/azureclients/armclient/util.go

@@ -123,7 +123,8 @@ func DoHackRegionalRetryDecorator(c *Client) autorest.SendDecorator {
 			// Hack: retry the regional ARM endpoint in case of ARM traffic split and arm resource group replication is too slow
 			// Empty content and 2xx http status code are returned in this case.
 			// Issue: https://github.com/kubernetes-sigs/cloud-provider-azure/issues/1296
-			emptyResp := (response.ContentLength == 0 || trimmed == "" || trimmed == "{}") && response.StatusCode >= 200 && response.StatusCode < 300
+			// Update: ContentLength == -1 is also considered because ARM can possibly return ContentLength -1 and StatusCode 200.
+			emptyResp := (response.ContentLength == 0 || response.ContentLength == -1 || trimmed == "" || trimmed == "{}") && response.StatusCode >= 200 && response.StatusCode < 300
 			if !emptyResp {
 				if rerr == nil || response.StatusCode == http.StatusNotFound || c.regionalEndpoint == "" {
 					return response, rerr
@@ -158,7 +159,7 @@ func DoHackRegionalRetryDecorator(c *Client) autorest.SendDecorator {
 			klog.V(6).Infof("Send.sendRegionalRequest on ResourceGroupNotFound error. Retrying regional host: %s", html.EscapeString(request.Host))
 
 			regionalResponse, regionalError := s.Do(request)
-			// only use the result if the regional request actually goes through and returns 2xx status code, for two reasons:
+			// only use the result if the regional request actually goes through, returns 2xx status code and has valid ContentLength (not -1 or 0), for two reasons:
 			// 1. the retry on regional ARM host approach is a hack.
 			// 2. the concatenated regional uri could be wrong as the rule is not officially declared by ARM.
 			if regionalResponse == nil || regionalResponse.StatusCode > 299 {
@@ -167,9 +168,15 @@ func DoHackRegionalRetryDecorator(c *Client) autorest.SendDecorator {
 					regionalErrStr = regionalError.Error()
 				}
 
-				klog.V(6).Infof("Send.sendRegionalRequest failed to get response from regional host, error: '%s'. Ignoring the result.", regionalErrStr)
+				klog.V(6).Infof("Send.sendRegionalRequest failed to get response from regional host, error: %q. Ignoring the result.", regionalErrStr)
 				return response, rerr
 			}
+			if regionalResponse.StatusCode >= 200 && regionalResponse.StatusCode < 300 && (regionalResponse.ContentLength == -1 || regionalResponse.ContentLength == 0) {
+				contentLengthErrStr := fmt.Sprintf("empty response with ContentLength %d and StatusCode %d", regionalResponse.ContentLength, regionalResponse.StatusCode)
+				klog.V(6).Infof(contentLengthErrStr)
+				return response, fmt.Errorf(contentLengthErrStr)
+			}
+
 			return regionalResponse, regionalError
 		})
 	}