add allow header for response code 405

Author: JoeCqupt

netty/src/main/java/io/grpc/netty/NettyServerHandler.java

@@ -60,6 +60,7 @@
 import io.netty.channel.ChannelFutureListener;
 import io.netty.channel.ChannelHandlerContext;
 import io.netty.channel.ChannelPromise;
+import io.netty.handler.codec.http.HttpHeaderNames;
 import io.netty.handler.codec.http2.DecoratingHttp2ConnectionEncoder;
 import io.netty.handler.codec.http2.DecoratingHttp2FrameWriter;
 import io.netty.handler.codec.http2.DefaultHttp2Connection;
@@ -70,6 +71,7 @@
 import io.netty.handler.codec.http2.DefaultHttp2Headers;
 import io.netty.handler.codec.http2.DefaultHttp2LocalFlowController;
 import io.netty.handler.codec.http2.DefaultHttp2RemoteFlowController;
+import io.netty.handler.codec.http2.EmptyHttp2Headers;
 import io.netty.handler.codec.http2.Http2Connection;
 import io.netty.handler.codec.http2.Http2ConnectionAdapter;
 import io.netty.handler.codec.http2.Http2ConnectionDecoder;
@@ -480,8 +482,10 @@ private void onHeadersRead(ChannelHandlerContext ctx, int streamId, Http2Headers
       }
 
       if (!HTTP_METHOD.contentEquals(headers.method())) {
+        Http2Headers extraHeaders = new DefaultHttp2Headers();
+        extraHeaders.add(HttpHeaderNames.ALLOW, HTTP_METHOD);
         respondWithHttpError(ctx, streamId, 405, Status.Code.INTERNAL,
-            String.format("Method '%s' is not supported", headers.method()));
+            String.format("Method '%s' is not supported", headers.method()), extraHeaders);
         return;
       }
 
@@ -868,7 +872,13 @@ public boolean visit(Http2Stream stream) throws Http2Exception {
   }
 
   private void respondWithHttpError(
-      ChannelHandlerContext ctx, int streamId, int code, Status.Code statusCode, String msg) {
+          ChannelHandlerContext ctx, int streamId, int code, Status.Code statusCode, String msg) {
+    respondWithHttpError(ctx, streamId, code, statusCode, msg, EmptyHttp2Headers.INSTANCE);
+  }
+
+  private void respondWithHttpError(
+      ChannelHandlerContext ctx, int streamId, int code, Status.Code statusCode, String msg,
+      Http2Headers extraHeaders) {
     Metadata metadata = new Metadata();
     metadata.put(InternalStatus.CODE_KEY, statusCode.toStatus());
     metadata.put(InternalStatus.MESSAGE_KEY, msg);
@@ -880,6 +890,7 @@ private void respondWithHttpError(
     for (int i = 0; i < serialized.length; i += 2) {
       headers.add(new AsciiString(serialized[i], false), new AsciiString(serialized[i + 1], false));
     }
+    headers.add(extraHeaders);
     encoder().writeHeaders(ctx, streamId, headers, 0, false, ctx.newPromise());
     ByteBuf msgBuf = ByteBufUtil.writeUtf8(ctx.alloc(), msg);
     encoder().writeData(ctx, streamId, msgBuf, 0, true, ctx.newPromise());

okhttp/src/main/java/io/grpc/okhttp/OkHttpServerTransport.java

@@ -20,6 +20,7 @@
 import static io.grpc.okhttp.OkHttpServerBuilder.MAX_CONNECTION_IDLE_NANOS_DISABLED;
 
 import com.google.common.base.Preconditions;
+import com.google.common.collect.Lists;
 import com.google.common.util.concurrent.Futures;
 import com.google.common.util.concurrent.ListenableFuture;
 import com.google.errorprone.annotations.concurrent.GuardedBy;
@@ -52,6 +53,7 @@
 import java.io.IOException;
 import java.net.Socket;
 import java.net.SocketException;
+import java.util.Collections;
 import java.util.List;
 import java.util.Locale;
 import java.util.Map;
@@ -772,8 +774,9 @@ public void headers(boolean outFinished,
       }
 
       if (!POST_METHOD.equals(httpMethod)) {
+        List<Header> extraHeaders = Lists.newArrayList(new Header(ByteString.encodeUtf8("allow"), POST_METHOD));
         respondWithHttpError(streamId, inFinished, 405, Status.Code.INTERNAL,
-            "HTTP Method is not supported: " + asciiString(httpMethod));
+            "HTTP Method is not supported: " + asciiString(httpMethod), extraHeaders);
         return;
       }
 
@@ -1065,12 +1068,18 @@ private void streamError(int streamId, ErrorCode errorCode, String reason) {
     }
 
     private void respondWithHttpError(
-        int streamId, boolean inFinished, int httpCode, Status.Code statusCode, String msg) {
+            int streamId, boolean inFinished, int httpCode, Status.Code statusCode, String msg) {
+      respondWithHttpError(streamId, inFinished, httpCode, statusCode, msg, Collections.emptyList());
+    }
+
+    private void respondWithHttpError(
+        int streamId, boolean inFinished, int httpCode, Status.Code statusCode, String msg, List<Header> extraHeaders) {
       Metadata metadata = new Metadata();
       metadata.put(InternalStatus.CODE_KEY, statusCode.toStatus());
       metadata.put(InternalStatus.MESSAGE_KEY, msg);
       List<Header> headers =
           Headers.createHttpResponseHeaders(httpCode, "text/plain; charset=utf-8", metadata);
+      headers.addAll(extraHeaders);
       Buffer data = new Buffer().writeUtf8(msg);
 
       synchronized (lock) {