#21282 Identify which node a response comes from

* #21282 adding the metadata interceptor

* #21282 adding unit test

* #21282 feedback and unit test

* #21282 adding more doc

* #21282 unit test feedback

* #21282 adding the ability to show the node id by query string

* #21282 feedback done

* #21282 fixing unit test

* #21282 fixing a test again

dotCMS/src/integration-test/java/com/dotcms/MainSuite.java

@@ -32,6 +32,7 @@
 import com.dotcms.enterprise.publishing.staticpublishing.LanguageFolderTest;
 import com.dotcms.enterprise.publishing.staticpublishing.StaticPublisherIntegrationTest;
 import com.dotcms.enterprise.rules.RulesAPIImplIntegrationTest;
+import com.dotcms.filters.interceptor.meta.MetaWebInterceptorTest;
 import com.dotcms.graphql.DotGraphQLHttpServletTest;
 import com.dotcms.integritycheckers.HostIntegrityCheckerTest;
 import com.dotcms.junit.MainBaseSuite;
@@ -495,6 +496,7 @@
         Task211012AddCompanyDefaultLanguageTest.class,
         StaticPublisherIntegrationTest.class,
         HostIntegrityCheckerTest.class,
+        MetaWebInterceptorTest.class,
         BrowserUtilTest.class,
         Task211101AddContentletAsJsonColumnTest.class,
         ContentletJsonAPITest.class,

dotCMS/src/integration-test/java/com/dotcms/filters/interceptor/meta/MetaWebInterceptorTest.java

@@ -0,0 +1,107 @@
+package com.dotcms.filters.interceptor.meta;
+
+import com.dotcms.enterprise.ClusterUtilProxy;
+import com.dotcms.mock.response.MockHeaderResponse;
+import com.dotcms.util.IntegrationTestInitService;
+import com.dotmarketing.business.APILocator;
+import com.dotmarketing.util.Config;
+import com.dotmarketing.util.StringUtils;
+import com.liferay.util.StringPool;
+import io.vavr.control.Try;
+import org.junit.Assert;
+import org.junit.BeforeClass;
+import org.junit.Test;
+
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
+import java.io.IOException;
+import java.util.Collections;
+
+import static org.mockito.Mockito.mock;
+
+/**
+ * Unit test for {@link ResponseMetaDataWebInterceptor}
+ * @author jsanca
+ */
+public class MetaWebInterceptorTest {
+
+    private final HttpServletRequest request = mock(HttpServletRequest.class);
+    private final HttpServletResponse response = mock(HttpServletResponse.class);
+
+
+    @BeforeClass
+    public static void prepare() throws Exception {
+        //Setting web app environment
+        IntegrationTestInitService.getInstance().init();
+    }
+
+    /**
+     * Method to test: {@link ResponseMetaDataWebInterceptor#intercept(HttpServletRequest, HttpServletResponse)}
+     * Given Scenario: calling it adds the header x-dot-server
+     * ExpectedResult: the header is added
+     * @throws IOException
+     */
+    @Test
+    public void check_header_x_dot_server()  {
+
+        final ResponseMetaDataWebInterceptor metaWebInterceptor = new ResponseMetaDataWebInterceptor();
+        final MockHeaderResponse mockHeaderResponse = new MockHeaderResponse(response);
+        metaWebInterceptor.intercept(request, mockHeaderResponse);
+
+        final String header = mockHeaderResponse.getHeader(ResponseMetaDataWebInterceptor.X_DOT_SERVER_HEADER);
+        Assert.assertNotNull(header);
+
+        final String tokenHeader = "unknown" + StringPool.PIPE + StringUtils.shortify(APILocator.getServerAPI().readServerId(), 10);
+
+        Assert.assertEquals(tokenHeader, header);
+    }
+
+
+    /**
+     * Method to test: {@link ResponseMetaDataWebInterceptor#intercept(HttpServletRequest, HttpServletResponse)}
+     * Given Scenario: calling it does not adds the header x-dot-server
+     * ExpectedResult: the header is not added
+     * @throws IOException
+     */
+    @Test
+    public void check_header_x_dot_server_config_disable()  {
+
+        try {
+            Config.setProperty(ResponseMetaDataWebInterceptor.RESPONSE_HEADER_ADD_NODE_ID, false);
+            final ResponseMetaDataWebInterceptor metaWebInterceptor = new ResponseMetaDataWebInterceptor();
+            final MockHeaderResponse mockHeaderResponse = new MockHeaderResponse(response);
+            metaWebInterceptor.intercept(request, mockHeaderResponse);
+
+            final String header = mockHeaderResponse.getHeader(ResponseMetaDataWebInterceptor.X_DOT_SERVER_HEADER);
+            Assert.assertNull(header);
+        } finally {
+
+            Config.setProperty(ResponseMetaDataWebInterceptor.RESPONSE_HEADER_ADD_NODE_ID, true);
+        }
+    }
+
+
+    /**
+     * Method to test: {@link ResponseMetaDataWebInterceptor#intercept(HttpServletRequest, HttpServletResponse)}
+     * Given Scenario: calling it adds the header x-dot-server, but do not includes the node name (unknown instead)
+     * ExpectedResult: the header is added without node name
+     * @throws IOException
+     */
+    @Test
+    public void check_header_x_dot_server_config_disable_node_name()  {
+
+        try {
+            Config.setProperty(ResponseMetaDataWebInterceptor.RESPONSE_HEADER_ADD_NODE_ID_INCLUDE_NODE_NAME, false);
+            final ResponseMetaDataWebInterceptor metaWebInterceptor = new ResponseMetaDataWebInterceptor();
+            final MockHeaderResponse mockHeaderResponse = new MockHeaderResponse(response);
+            metaWebInterceptor.intercept(request, mockHeaderResponse);
+
+            final String header = mockHeaderResponse.getHeader(ResponseMetaDataWebInterceptor.X_DOT_SERVER_HEADER);
+            Assert.assertNotNull(header);
+            Assert.assertTrue(header.startsWith("unknown|"));
+        } finally {
+
+            Config.setProperty(ResponseMetaDataWebInterceptor.RESPONSE_HEADER_ADD_NODE_ID, true);
+        }
+    }
+}

dotCMS/src/main/java/com/dotcms/filters/interceptor/meta/ResponseMetaDataWebInterceptor.java

@@ -0,0 +1,69 @@
+package com.dotcms.filters.interceptor.meta;
+
+import com.dotcms.enterprise.ClusterUtilProxy;
+import com.dotcms.filters.interceptor.Result;
+import com.dotcms.filters.interceptor.WebInterceptor;
+import com.dotmarketing.business.APILocator;
+import com.dotmarketing.util.Config;
+import com.dotmarketing.util.StringUtils;
+import com.liferay.util.StringPool;
+import io.vavr.Lazy;
+import io.vavr.control.Try;
+
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
+import java.io.Serializable;
+import java.util.Collections;
+import java.util.Map;
+
+/**
+ * Interceptor that adds meta info to the dotcms response
+ *
+ * includes:
+ *  - x-dot-server header, contains the node name + server id (this helps to identified on a cluster context which node has committed the response)
+ *
+ * @author jsanca
+ */
+public class ResponseMetaDataWebInterceptor implements WebInterceptor {
+
+    public static final String RESPONSE_HEADER_ADD_NODE_ID = "RESPONSE_HEADER_ADD_NODE_ID";
+    public static final String RESPONSE_HEADER_ADD_NODE_ID_INCLUDE_NODE_NAME = "RESPONSE_HEADER_ADD_NODE_ID_INCLUDE_NODE_NAME";
+    public static final String X_DOT_SERVER_HEADER = "x-dot-server";
+
+    private static final String FRIENDLY_NAME = "friendlyName";
+    private static final String UNKNOWN = "unknown";
+    private static final String NODEID_PARAM = "nodeid";
+    private static final String TRUE_VALUE = "true";
+
+    private final Lazy<Boolean> responseHeaderAddNodeId = Lazy.of(()-> Config.getBooleanProperty(RESPONSE_HEADER_ADD_NODE_ID, true));
+    private final Lazy<String>  serverId                = Lazy.of(()-> StringUtils.shortify(APILocator.getServerAPI().readServerId(), 10));
+    private final Lazy<String>  nodeName                = Lazy.of(this::getNodeName);
+
+    private final String getNodeName () {
+
+        if (Config.getBooleanProperty(RESPONSE_HEADER_ADD_NODE_ID_INCLUDE_NODE_NAME, true)) {
+
+            final Map<String, Serializable> nodeInfoMap = Try.of(() -> ClusterUtilProxy.getNodeInfo()).getOrElse(Collections.emptyMap());
+            return nodeInfoMap.getOrDefault(FRIENDLY_NAME, UNKNOWN).toString();
+        }
+
+        return UNKNOWN;
+    }
+
+    @Override
+    public Result intercept(final HttpServletRequest request, final HttpServletResponse response) {
+
+        if (responseHeaderAddNodeId.get() ||
+                TRUE_VALUE.equals(request.getParameter(NODEID_PARAM))) {
+
+            response.addHeader(X_DOT_SERVER_HEADER,
+                            nodeName.get()
+                            + StringPool.PIPE
+                            + serverId.get()
+            );
+        }
+
+        return Result.NEXT;
+    }
+
+} // E:O:F:MetaWebInterceptor.

dotCMS/src/main/java/com/dotcms/http/CircuitBreakerUrlBuilder.java

@@ -119,7 +119,7 @@ public CircuitBreakerUrl build() {
             default:
                 request = new HttpGet(proxyUrl);
                 break;
-        }
+        } 
 
         return new CircuitBreakerUrl(this.proxyUrl, this.timeout, this.circuitBreaker, request, this.params, this.headers, this.verbose, this.rawData);
 

dotCMS/src/main/java/com/dotmarketing/filters/InterceptorFilter.java

@@ -3,6 +3,7 @@
 import com.dotcms.ema.EMAWebInterceptor;
 import com.dotcms.filters.interceptor.AbstractWebInterceptorSupportFilter;
 import com.dotcms.filters.interceptor.WebInterceptorDelegate;
+import com.dotcms.filters.interceptor.meta.ResponseMetaDataWebInterceptor;
 import com.dotcms.graphql.GraphqlCacheWebInterceptor;
 import javax.servlet.FilterConfig;
 import javax.servlet.ServletException;
@@ -28,6 +29,7 @@ private void addInterceptors(final FilterConfig config) {
 
         delegate.add(new EMAWebInterceptor());
         delegate.add(new GraphqlCacheWebInterceptor());
+        delegate.add(new ResponseMetaDataWebInterceptor());
     } // addInterceptors.
 
-} // E:O:F:InterceptorFilter.
+} // E:O:F:InterceptorFilter.

dotCMS/src/main/java/com/liferay/util/StringPool.java

@@ -85,4 +85,6 @@ public class StringPool {
 
 	public static final String PLUS = "+";
 
+	public static final String PIPE = "|";
+
 }