Adding the provision of redirecting HTTP requests to HTTPS

app/Global.java

@@ -14,17 +14,21 @@
  * the License.
  */
 
+import com.google.common.base.Strings;
 import com.linkedin.drelephant.DrElephant;
+import com.linkedin.drelephant.ElephantContext;
 import com.sun.security.sasl.util.AbstractSaslImpl;
-
-import play.Application;
-import play.GlobalSettings;
-import play.Logger;
-
 import java.io.IOException;
 import java.lang.reflect.Field;
 import java.lang.reflect.Modifier;
 import java.util.logging.Level;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+import play.Application;
+import play.GlobalSettings;
+import play.Logger;
+import play.api.mvc.Handler;
+import play.mvc.Http;
 
 
 /**
@@ -34,11 +38,24 @@ public class Global extends GlobalSettings {
 
   DrElephant _drElephant;
 
+  private final String INVALID_PORT = "-1";
+  private final String HTTPS_PROTOCOL = "https://";
+  private final String HTTP_PORT_CONFIG_NAME = "http_port";
+  private final String HTTPS_PORT_CONFIG_NAME = "https_port";
+
+  private String HTTP_PORT;
+  private String HTTPS_PORT;
+
   public void onStart(Application app) {
     Logger.info("Starting Application...");
 
     fixJavaKerberos();
 
+    HTTP_PORT = ElephantContext.instance().getElephnatConf()
+        .getProperty(HTTP_PORT_CONFIG_NAME);
+    HTTPS_PORT = ElephantContext.instance().getElephnatConf()
+        .getProperty(HTTPS_PORT_CONFIG_NAME);
+
     try {
       _drElephant = new DrElephant();
       _drElephant.start();
@@ -80,11 +97,46 @@ private static void fixJavaKerberos() {
 
   }
 
+  /**
+   * This method is overridden to re-direct all the requests to HTTP endpoint of Dr.Elephant to
+   * the respective HTTPS enabled endpoint(If such endpoints exists)
+   * @param requestHeader Request Header
+   * @return The Handler to appropriately handle the given request
+   */
+  @Override
+  public Handler onRouteRequest(Http.RequestHeader requestHeader) {
+    if (!Strings.isNullOrEmpty(HTTP_PORT) && !Strings.isNullOrEmpty(HTTPS_PORT)) {
+      String port = INVALID_PORT;
+      if (!Strings.isNullOrEmpty(requestHeader.host())) {
+        port = getPortFromHostAddress(requestHeader.host());
+      }
+      if (!port.equals(INVALID_PORT) && port.equals(HTTP_PORT)) {
+        return controllers.Default.redirect(HTTPS_PROTOCOL + requestHeader.host().replace(port, HTTPS_PORT)
+            + requestHeader.uri());
+      }
+    }
+    return super.onRouteRequest(requestHeader);
+  }
+
   static void setFinalStatic(Field field, Object newValue) throws Exception {
     field.setAccessible(true);
     Field modifiersField = Field.class.getDeclaredField("modifiers");
     modifiersField.setAccessible(true);
     modifiersField.setInt(field, field.getModifiers() & ~Modifier.FINAL);
     field.set(null, newValue);
   }
+
+  /**
+   *
+   * @param hostAddress The hostAddress string which will be of format "elephant.abc.com:8080"
+   * @return Return the port of the of the hostAddress if exists else return INVALID_PORT
+   */
+  private String getPortFromHostAddress(String hostAddress) {
+    String patterForPort = "(.+):([\\d]{1,5})";
+    Matcher matcher = Pattern.compile(patterForPort).matcher(hostAddress);
+    if (matcher.find()) {
+      return matcher.group(2);
+    }
+    return INVALID_PORT;
+  }
 }