Add support for syncing replica modifications (#11104)

when bidirectional replication is set up.

If ReplicaModifications is enabled in the replication
configuration, sync metadata updates to source if
replication rules are met. By default, if this
configuration is unset, MinIO automatically sync's
metadata updates on replica back to the source.

pkg/bucket/replication/replication.go

@@ -58,6 +58,7 @@ var (
 	errReplicationUniquePriority      = Errorf("Replication configuration has duplicate priority")
 	errReplicationDestinationMismatch = Errorf("The destination bucket must be same for all rules")
 	errRoleArnMissing                 = Errorf("Missing required parameter `Role` in ReplicationConfiguration")
+	errInvalidSourceSelectionCriteria = Errorf("Invalid ReplicaModification status")
 )
 
 // Config - replication configuration specified in
@@ -78,6 +79,16 @@ func ParseConfig(reader io.Reader) (*Config, error) {
 	if err := xml.NewDecoder(io.LimitReader(reader, maxReplicationConfigSize)).Decode(&config); err != nil {
 		return nil, err
 	}
+	// By default, set replica modification to enabled if unset.
+	for i := range config.Rules {
+		if len(config.Rules[i].SourceSelectionCriteria.ReplicaModifications.Status) == 0 {
+			config.Rules[i].SourceSelectionCriteria = SourceSelectionCriteria{
+				ReplicaModifications: ReplicaModifications{
+					Status: Enabled,
+				},
+			}
+		}
+	}
 	return &config, nil
 }
 
@@ -136,6 +147,7 @@ type ObjectOpts struct {
 	DeleteMarker bool
 	SSEC         bool
 	OpType       Type
+	Replica      bool
 }
 
 // FilterActionableRules returns the rules actions that need to be executed
@@ -187,9 +199,8 @@ func (c Config) Replicate(obj ObjectOpts) bool {
 			default:
 				return rule.DeleteMarkerReplication.Status == Enabled
 			}
-		} else { // regular object/metadata replication
-			return true
-		}
+		} // regular object/metadata replication
+		return rule.MetadataReplicate(obj)
 	}
 	return false
 }