Recover from all refresh-token related errors by requesting a new token

- When the UAA throws an error other than HTTP 401, the refresh token
  flow fails, and can lead to irrecoverable errors where there
  application needs to be restarted. This changes ensure we are
  resilitent to all UAA errors. The downside is that we may not retry
  using a refresh token when it fails for an unrelated reason (eg HTTP
  503), requesting access tokens more frequently. The impact should be
  extremely marginal.

Signed-off-by: Daniel Garnier-Moiroux <daniel.garnier-moiroux@broadcom.com>

Author: Kehrlann

cloudfoundry-client-reactor/src/main/java/org/cloudfoundry/reactor/tokenprovider/AbstractUaaTokenProvider.java

@@ -25,7 +25,6 @@
 import io.jsonwebtoken.JwtParser;
 import io.jsonwebtoken.Jwts;
 import io.netty.handler.codec.http.HttpHeaders;
-import io.netty.handler.codec.http.HttpResponseStatus;
 import io.netty.util.AsciiString;
 import java.time.LocalDateTime;
 import java.time.ZoneId;
@@ -46,7 +45,6 @@
 import org.cloudfoundry.reactor.util.Operator;
 import org.cloudfoundry.reactor.util.OperatorContext;
 import org.cloudfoundry.reactor.util.UserAgent;
-import org.cloudfoundry.uaa.UaaException;
 import org.immutables.value.Value;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
@@ -253,12 +251,8 @@ private Mono<String> refreshToken(ConnectionContext connectionContext, String re
                         connectionContext,
                         refreshTokenGrantTokenRequestTransformer(refreshToken),
                         tokensExtractor(connectionContext))
-                .onErrorResume(
-                        t ->
-                                t instanceof UaaException
-                                        && ((UaaException) t).getStatusCode()
-                                                == HttpResponseStatus.UNAUTHORIZED.code(),
-                        t -> Mono.empty());
+                .doOnError(t -> LOGGER.error("Refresh token grant error.", t))
+                .onErrorResume(t -> Mono.empty());
     }
 
     private BiConsumer<HttpClientRequest, HttpClientForm> refreshTokenGrantTokenRequestTransformer(