s3: add grpc server to accept configuration changes

weed/s3api/s3api_server_grpc.go

@@ -0,0 +1,16 @@
+package s3api
+
+import (
+	"context"
+	"github.com/chrislusf/seaweedfs/weed/pb/s3_pb"
+)
+
+func (s3a *S3ApiServer) Configure(ctx context.Context, request *s3_pb.ConfigureRequest) (*s3_pb.ConfigureResponse, error) {
+
+	if err := s3a.iam.LoadS3ApiConfigurationFromBytes(request.ConfigurationFileContent); err != nil {
+		return nil, err
+	}
+
+	return &s3_pb.ConfigureResponse{}, nil
+
+}