[FAB-10079] Use successful response from discovery

Loop through all responses and choose the first
response without error.

Change-Id: I5886fbaba3151710be0f058bc9fdbd7c76b459c2
Signed-off-by: Bob Stasyszyn <Bob.Stasyszyn@securekey.com>

Author: bstasyszyn

pkg/client/common/discovery/dynamicdiscovery/chservice.go

@@ -93,12 +93,17 @@ func (s *channelService) evaluate(ctx contextAPI.Channel, responses []fabdiscove
 	// TODO: In a future patch:
 	// - validate the signatures in the responses
 	// - ensure N responses match according to the policy
-	// For now just pick the first response
-	response := responses[0]
-	endpoints, err := response.ForChannel(ctx.ChannelID()).Peers()
-	if err != nil {
-		return nil, errors.Wrapf(err, "error getting peers from discovery response")
+	// For now just pick the first successful response
+
+	var lastErr error
+	for _, response := range responses {
+		endpoints, err := response.ForChannel(ctx.ChannelID()).Peers()
+		if err != nil {
+			lastErr = errors.Wrapf(err, "error getting peers from discovery response")
+			logger.Warn(lastErr.Error())
+			continue
+		}
+		return asPeers(ctx, endpoints), nil
 	}
-
-	return asPeers(ctx, endpoints), nil
+	return nil, lastErr
 }