Fix sse for notifications behind nginx reverse proxy (#1650)

gradle/changelog/notifications_behind_nginx.yaml

@@ -0,0 +1,2 @@
+- type: fixed
+  description: SSE for notifications behind nginx reverse proxy ([#1650](https://github.com/scm-manager/scm-manager/pull/1650))

scm-core/src/main/java/sonia/scm/sse/SseResponse.java

@@ -0,0 +1,41 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2020-present Cloudogu GmbH and Contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package sonia.scm.sse;
+
+import javax.ws.rs.NameBinding;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+
+/**
+ * Marks an JAX-RS Endpoint as SseResponse.
+ * An JAX-RS Filter will add some http headers to the response
+ * to avoid common problems with SSE such as caching or buffering behind a reverse proxy.
+ *
+ * @since 2.19.0
+ */
+@NameBinding
+@Retention(RetentionPolicy.RUNTIME)
+public @interface SseResponse {
+}

scm-test/src/main/java/sonia/scm/web/RestDispatcher.java

@@ -21,7 +21,7 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  * SOFTWARE.
  */
-    
+
 package sonia.scm.web;
 
 import com.fasterxml.jackson.databind.ObjectMapper;
@@ -31,6 +31,7 @@ import org.jboss.resteasy.mock.MockDispatcherFactory;
 import org.jboss.resteasy.spi.Dispatcher;
 import org.jboss.resteasy.spi.HttpRequest;
 import org.jboss.resteasy.spi.HttpResponse;
+import org.jboss.resteasy.spi.ResteasyProviderFactory;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import sonia.scm.AlreadyExistsException;
@@ -74,6 +75,10 @@ public class RestDispatcher {
     exceptionMapper.registerException(exceptionClass, status);
   }
 
+  public ResteasyProviderFactory getProviderFactory() {
+    return dispatcher.getProviderFactory();
+  }
+
   public <T> void putDefaultContextObject(Class<T> clazz, T object) {
     dispatcher.getDefaultContextObjects().put(clazz, object);
   }

scm-webapp/src/main/java/sonia/scm/api/rest/SseHeaderResponseFilter.java

@@ -0,0 +1,59 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2020-present Cloudogu GmbH and Contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package sonia.scm.api.rest;
+
+import sonia.scm.sse.SseResponse;
+
+import javax.ws.rs.container.ContainerRequestContext;
+import javax.ws.rs.container.ContainerResponseContext;
+import javax.ws.rs.container.ContainerResponseFilter;
+import javax.ws.rs.core.CacheControl;
+import javax.ws.rs.core.MultivaluedMap;
+import javax.ws.rs.ext.Provider;
+import java.io.IOException;
+
+@Provider
+@SseResponse
+public class SseHeaderResponseFilter implements ContainerResponseFilter {
+
+  @Override
+  public void filter(ContainerRequestContext requestContext, ContainerResponseContext responseContext) throws IOException {
+    MultivaluedMap<String, Object> headers = responseContext.getHeaders();
+    cacheControl(headers);
+    avoidNginxBuffering(headers);
+  }
+
+  private void avoidNginxBuffering(MultivaluedMap<String, Object> headers) {
+    headers.add("X-Accel-Buffering", "no");
+  }
+
+  private void cacheControl(MultivaluedMap<String, Object> headers) {
+    CacheControl cacheControl = new CacheControl();
+    cacheControl.setNoCache(true);
+
+    headers.remove("Cache-Control");
+    headers.add("Cache-Control", cacheControl);
+  }
+}

scm-webapp/src/main/java/sonia/scm/api/v2/CacheControlResponseFilter.java

@@ -21,7 +21,7 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  * SOFTWARE.
  */
-    
+
 package sonia.scm.api.v2;
 
 import org.slf4j.Logger;
@@ -43,12 +43,20 @@ public class CacheControlResponseFilter implements ContainerResponseFilter {
 
   @Override
   public void filter(ContainerRequestContext requestContext, ContainerResponseContext responseContext) {
-    if (!isCacheable(responseContext)) {
+    if (shouldAppendCachingHeader(responseContext)) {
       LOG.trace("add no-cache header to response");
       responseContext.getHeaders().add("Cache-Control", "no-cache");
     }
   }
 
+  private boolean shouldAppendCachingHeader(ContainerResponseContext responseContext) {
+    return !hasAlreadyCacheControl(responseContext) && !isCacheable(responseContext);
+  }
+
+  private boolean hasAlreadyCacheControl(ContainerResponseContext responseContext) {
+    return responseContext.getHeaders().containsKey("Cache-Control");
+  }
+
   private boolean isCacheable(ContainerResponseContext responseContext) {
     return hasLastModifiedDate(responseContext) || hasEntityTag(responseContext);
   }

scm-webapp/src/main/java/sonia/scm/api/v2/resources/NotificationResource.java

@@ -41,6 +41,7 @@ import sonia.scm.security.SessionId;
 import sonia.scm.sse.Channel;
 import sonia.scm.sse.ChannelRegistry;
 import sonia.scm.sse.Registration;
+import sonia.scm.sse.SseResponse;
 import sonia.scm.web.VndMediaType;
 
 import javax.inject.Inject;
@@ -175,6 +176,7 @@ public class NotificationResource {
       mediaType = VndMediaType.ERROR_TYPE,
       schema = @Schema(implementation = ErrorDto.class)
     ))
+  @SseResponse
   public void subscribe(@Context Sse sse, @Context SseEventSink eventSink, @QueryParam(SessionId.PARAMETER) SessionId sessionId) {
     Channel channel = channelRegistry.channel(NotificationChannelId.current());
     channel.register(new Registration(sessionId, sse, eventSink));

scm-webapp/src/test/java/sonia/scm/api/rest/SseHeaderResponseFilterTest.java

@@ -0,0 +1,131 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2020-present Cloudogu GmbH and Contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package sonia.scm.api.rest;
+
+import org.assertj.core.api.AbstractStringAssert;
+import org.jboss.resteasy.mock.MockHttpRequest;
+import org.jboss.resteasy.mock.MockHttpResponse;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import sonia.scm.api.v2.CacheControlResponseFilter;
+import sonia.scm.sse.SseResponse;
+import sonia.scm.web.RestDispatcher;
+
+import javax.ws.rs.GET;
+import javax.ws.rs.Path;
+import javax.ws.rs.Produces;
+import javax.ws.rs.core.MediaType;
+import java.net.URISyntaxException;
+import java.util.List;
+import java.util.stream.Collectors;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+class SseHeaderResponseFilterTest {
+
+  private RestDispatcher restDispatcher;
+
+  @BeforeEach
+  void setUp() {
+    restDispatcher = new RestDispatcher();
+    restDispatcher.getProviderFactory().register(new SseHeaderResponseFilter());
+    restDispatcher.addSingletonResource(new FakeSseResource());
+  }
+
+  @Test
+  void shouldAddResponseHeaders() throws URISyntaxException {
+    MockHttpResponse response = invoke("/fake/sse");
+
+    assertThat(response.getStatus()).isEqualTo(200);
+    assertContentType(response, MediaType.SERVER_SENT_EVENTS_TYPE);
+    assertStringHeader(response, "Cache-Control").isEqualTo("no-cache, no-transform");
+    assertStringHeader(response, "X-Accel-Buffering").isEqualTo("no");
+  }
+
+  @Test
+  void shouldSkipNonSseResponses() throws URISyntaxException {
+    MockHttpResponse response = invoke("/fake/non");
+
+    assertThat(response.getStatus()).isEqualTo(200);
+    assertContentType(response, MediaType.TEXT_PLAIN_TYPE);
+    assertStringHeader(response, "Cache-Control").isNull();
+    assertStringHeader(response, "X-Accel-Buffering").isNull();
+  }
+
+  @Test
+  void shouldAddCacheControlOnlyOnce() throws URISyntaxException {
+    restDispatcher.getProviderFactory().register(new CacheControlResponseFilter());
+    MockHttpResponse response = invoke("/fake/sse");
+
+    List<String> values = response.getOutputHeaders()
+      .get("Cache-Control")
+      .stream()
+      .map(Object::toString)
+      .collect(Collectors.toList());
+
+    assertThat(values).containsOnly("no-cache, no-transform");
+  }
+
+  private void assertContentType(MockHttpResponse response, MediaType expected) {
+    MediaType contentType = (MediaType) response.getOutputHeaders().getFirst("Content-Type");
+    assertThat(contentType.isCompatible(expected)).isTrue();
+  }
+
+  private AbstractStringAssert<?> assertStringHeader(MockHttpResponse response, String headerName) {
+    Object value = response.getOutputHeaders().getFirst(headerName);
+    if (value != null) {
+      return assertThat(value.toString());
+    }
+    return assertThat((String) null);
+  }
+
+  private MockHttpResponse invoke(String uri) throws URISyntaxException {
+    MockHttpRequest request = MockHttpRequest.get(uri);
+    MockHttpResponse response = new MockHttpResponse();
+    restDispatcher.invoke(request, response);
+    return response;
+  }
+
+  @Path("/fake")
+  public static class FakeSseResource {
+
+    @GET
+    @SseResponse
+    @Path("sse")
+    @Produces(MediaType.SERVER_SENT_EVENTS)
+    public String fakeSse() {
+      return "sse";
+    }
+
+    @GET
+    @Path("non")
+    @Produces(MediaType.TEXT_PLAIN)
+    public String nonSse() {
+      return "non-sse";
+    }
+
+  }
+
+}

scm-webapp/src/test/java/sonia/scm/api/v2/CacheControlResponseFilterTest.java

@@ -21,14 +21,14 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  * SOFTWARE.
  */
-    
+
 package sonia.scm.api.v2;
 
-import org.junit.Before;
-import org.junit.Test;
-import org.junit.runner.RunWith;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
 import org.mockito.Mock;
-import org.mockito.junit.MockitoJUnitRunner;
+import org.mockito.junit.jupiter.MockitoExtension;
 
 import javax.ws.rs.container.ContainerRequestContext;
 import javax.ws.rs.container.ContainerResponseContext;
@@ -36,10 +36,12 @@ import javax.ws.rs.core.EntityTag;
 import javax.ws.rs.core.MultivaluedMap;
 import java.util.Date;
 
-import static org.mockito.Mockito.*;
+import static org.mockito.Mockito.never;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
 
-@RunWith(MockitoJUnitRunner.class)
-public class CacheControlResponseFilterTest {
+@ExtendWith(MockitoExtension.class)
+class CacheControlResponseFilterTest {
 
   @Mock
   private ContainerRequestContext requestContext;
@@ -50,22 +52,22 @@ public class CacheControlResponseFilterTest {
   @Mock
   private MultivaluedMap<String, Object> headers;
 
-  private CacheControlResponseFilter filter = new CacheControlResponseFilter();
+  private final CacheControlResponseFilter filter = new CacheControlResponseFilter();
 
-  @Before
-  public void setUpMocks() {
+  @BeforeEach
+  void setUpMocks() {
     when(responseContext.getHeaders()).thenReturn(headers);
   }
 
   @Test
-  public void filterShouldAddCacheControlHeader() {
+  void shouldAddCacheControlHeader() {
     filter.filter(requestContext, responseContext);
 
     verify(headers).add("Cache-Control", "no-cache");
   }
 
   @Test
-  public void filterShouldNotSetHeaderIfLastModifiedIsNotNull() {
+  void shouldNotSetHeaderIfLastModifiedIsNotNull() {
     when(responseContext.getLastModified()).thenReturn(new Date());
 
     filter.filter(requestContext, responseContext);
@@ -74,7 +76,7 @@ public class CacheControlResponseFilterTest {
   }
 
   @Test
-  public void filterShouldNotSetHeaderIfEtagIsNotNull() {
+  void shouldNotSetHeaderIfEtagIsNotNull() {
     when(responseContext.getEntityTag()).thenReturn(new EntityTag("42"));
 
     filter.filter(requestContext, responseContext);
@@ -82,4 +84,13 @@ public class CacheControlResponseFilterTest {
     verify(headers, never()).add("Cache-Control", "no-cache");
   }
 
+  @Test
+  void shouldNotOverrideExistingCacheControl() {
+    when(headers.containsKey("Cache-Control")).thenReturn(true);
+
+    filter.filter(requestContext, responseContext);
+
+    verify(headers, never()).add("Cache-Control", "no-cache");
+  }
+
 }