Add HttpScheme Support in HttpToHttp2ConnectionHandler (netty#10641)

Motivation:
We should have a method to add `HttpScheme` if `HttpRequest` does not contain `x-http2-scheme` then we should use add it if `HttpToHttp2ConnectionHandler` is build using specified `HttpScheme`.

Modification:
Added `HttpScheme` in `HttpToHttp2ConnectionHandlerBuilder`.

Result:
Automatically add `HttpScheme` if missing in `HttpRequest`.

codec-http2/src/main/java/io/netty/handler/codec/http2/HttpToHttp2ConnectionHandler.java

@@ -23,6 +23,7 @@
 import io.netty.handler.codec.http.HttpContent;
 import io.netty.handler.codec.http.HttpHeaders;
 import io.netty.handler.codec.http.HttpMessage;
+import io.netty.handler.codec.http.HttpScheme;
 import io.netty.handler.codec.http.LastHttpContent;
 import io.netty.handler.codec.http2.Http2CodecUtil.SimpleChannelPromiseAggregator;
 import io.netty.util.ReferenceCountUtil;
@@ -38,6 +39,7 @@ public class HttpToHttp2ConnectionHandler extends Http2ConnectionHandler {
 
     private final boolean validateHeaders;
     private int currentStreamId;
+    private HttpScheme httpScheme;
 
     protected HttpToHttp2ConnectionHandler(Http2ConnectionDecoder decoder, Http2ConnectionEncoder encoder,
                                            Http2Settings initialSettings, boolean validateHeaders) {
@@ -48,8 +50,15 @@ protected HttpToHttp2ConnectionHandler(Http2ConnectionDecoder decoder, Http2Conn
     protected HttpToHttp2ConnectionHandler(Http2ConnectionDecoder decoder, Http2ConnectionEncoder encoder,
                                            Http2Settings initialSettings, boolean validateHeaders,
                                            boolean decoupleCloseAndGoAway) {
+        this(decoder, encoder, initialSettings, validateHeaders, decoupleCloseAndGoAway, null);
+    }
+
+    protected HttpToHttp2ConnectionHandler(Http2ConnectionDecoder decoder, Http2ConnectionEncoder encoder,
+                                           Http2Settings initialSettings, boolean validateHeaders,
+                                           boolean decoupleCloseAndGoAway, HttpScheme httpScheme) {
         super(decoder, encoder, initialSettings, decoupleCloseAndGoAway);
         this.validateHeaders = validateHeaders;
+        this.httpScheme = httpScheme;
     }
 
     /**
@@ -87,6 +96,12 @@ public void write(ChannelHandlerContext ctx, Object msg, ChannelPromise promise)
                 // Provide the user the opportunity to specify the streamId
                 currentStreamId = getStreamId(httpMsg.headers());
 
+                // Add HttpScheme if it's defined in constructor and header does not contain it.
+                if (httpScheme != null &&
+                        !httpMsg.headers().contains(HttpConversionUtil.ExtensionHeaderNames.SCHEME.text())) {
+                    httpMsg.headers().set(HttpConversionUtil.ExtensionHeaderNames.SCHEME.text(), httpScheme.name());
+                }
+
                 // Convert and write the headers.
                 Http2Headers http2Headers = HttpConversionUtil.toHttp2Headers(httpMsg, validateHeaders);
                 endStream = msg instanceof FullHttpMessage && !((FullHttpMessage) msg).content().isReadable();

codec-http2/src/main/java/io/netty/handler/codec/http2/HttpToHttp2ConnectionHandlerBuilder.java

@@ -16,6 +16,7 @@
 
 package io.netty.handler.codec.http2;
 
+import io.netty.handler.codec.http.HttpScheme;
 import io.netty.handler.codec.http2.Http2HeadersEncoder.SensitivityDetector;
 import io.netty.util.internal.UnstableApi;
 
@@ -26,6 +27,8 @@
 public final class HttpToHttp2ConnectionHandlerBuilder extends
         AbstractHttp2ConnectionHandlerBuilder<HttpToHttp2ConnectionHandler, HttpToHttp2ConnectionHandlerBuilder> {
 
+    private HttpScheme httpScheme;
+
     @Override
     public HttpToHttp2ConnectionHandlerBuilder validateHeaders(boolean validateHeaders) {
         return super.validateHeaders(validateHeaders);
@@ -58,7 +61,7 @@ public HttpToHttp2ConnectionHandlerBuilder connection(Http2Connection connection
 
     @Override
     public HttpToHttp2ConnectionHandlerBuilder codec(Http2ConnectionDecoder decoder,
-                                                        Http2ConnectionEncoder encoder) {
+                                                     Http2ConnectionEncoder encoder) {
         return super.codec(decoder, encoder);
     }
 
@@ -90,6 +93,17 @@ public HttpToHttp2ConnectionHandlerBuilder decoupleCloseAndGoAway(boolean decoup
         return super.decoupleCloseAndGoAway(decoupleCloseAndGoAway);
     }
 
+    /**
+     * Add {@code scheme} in {@link Http2Headers} if not already present.
+     *
+     * @param httpScheme {@link HttpScheme} type
+     * @return {@code this}.
+     */
+    public HttpToHttp2ConnectionHandlerBuilder httpScheme(HttpScheme httpScheme) {
+        this.httpScheme = httpScheme;
+        return self();
+    }
+
     @Override
     public HttpToHttp2ConnectionHandler build() {
         return super.build();
@@ -99,6 +113,6 @@ public HttpToHttp2ConnectionHandler build() {
     protected HttpToHttp2ConnectionHandler build(Http2ConnectionDecoder decoder, Http2ConnectionEncoder encoder,
                                                  Http2Settings initialSettings) {
         return new HttpToHttp2ConnectionHandler(decoder, encoder, initialSettings, isValidateHeaders(),
-                decoupleCloseAndGoAway());
+                decoupleCloseAndGoAway(), httpScheme);
     }
 }

codec-http2/src/test/java/io/netty/handler/codec/http2/HttpToHttp2ConnectionHandlerTest.java

@@ -37,6 +37,7 @@
 import io.netty.handler.codec.http.HttpHeaderNames;
 import io.netty.handler.codec.http.HttpHeaders;
 import io.netty.handler.codec.http.HttpRequest;
+import io.netty.handler.codec.http.HttpScheme;
 import io.netty.handler.codec.http.LastHttpContent;
 import io.netty.handler.codec.http2.Http2TestUtil.FrameCountDown;
 import io.netty.util.AsciiString;
@@ -147,6 +148,29 @@ public void testHeadersOnlyRequest() throws Exception {
         verifyHeadersOnly(http2Headers, writePromise, clientChannel.writeAndFlush(request, writePromise));
     }
 
+    @Test
+    public void testHttpScheme() throws Exception {
+        bootstrapEnv(2, 1, 0);
+        final FullHttpRequest request = new DefaultFullHttpRequest(HTTP_1_1, GET,
+                "http://my-user_name@www.example.org:5555/example");
+        final HttpHeaders httpHeaders = request.headers();
+        httpHeaders.setInt(HttpConversionUtil.ExtensionHeaderNames.STREAM_ID.text(), 5);
+        httpHeaders.set(HttpHeaderNames.HOST, "my-user_name@www.example.org:5555");
+        httpHeaders.add(of("foo"), of("goo"));
+        httpHeaders.add(of("foo"), of("goo2"));
+        httpHeaders.add(of("foo2"), of("goo2"));
+        final Http2Headers http2Headers =
+                new DefaultHttp2Headers().method(new AsciiString("GET")).path(new AsciiString("/example"))
+                        .authority(new AsciiString("www.example.org:5555")).scheme(new AsciiString("http"))
+                        .scheme(new AsciiString("http"))
+                        .add(new AsciiString("foo"), new AsciiString("goo"))
+                        .add(new AsciiString("foo"), new AsciiString("goo2"))
+                        .add(new AsciiString("foo2"), new AsciiString("goo2"));
+
+        ChannelPromise writePromise = newPromise();
+        verifyHeadersOnly(http2Headers, writePromise, clientChannel.writeAndFlush(request, writePromise));
+    }
+
     @Test
     public void testMultipleCookieEntriesAreCombined() throws Exception {
         bootstrapEnv(2, 1, 0);
@@ -520,6 +544,7 @@ protected void initChannel(Channel ch) throws Exception {
                 p.addLast(new HttpToHttp2ConnectionHandlerBuilder()
                            .server(true)
                            .frameListener(serverFrameCountDown)
+                           .httpScheme(HttpScheme.HTTP)
                            .build());
                 serverChannelLatch.countDown();
             }