feat: Implement production mode license verification in VaadinServletService (#23839)

Add runtime license verification for production mode.
License check failure is only logged, it does not prevent the application from running.

Author: TatuLund

flow-data/src/test/java/com/vaadin/flow/data/provider/DataCommunicatorAsyncTest.java

@@ -13,10 +13,12 @@
 import org.junit.Before;
 import org.junit.Test;
 import org.mockito.Mock;
+import org.mockito.Mockito;
 import org.mockito.MockitoAnnotations;
 
 import com.vaadin.flow.component.UI;
 import com.vaadin.flow.dom.Element;
+import com.vaadin.flow.function.DeploymentConfiguration;
 import com.vaadin.flow.internal.Range;
 import com.vaadin.flow.server.VaadinRequest;
 import com.vaadin.flow.server.VaadinService;
@@ -230,8 +232,9 @@ protected void init(VaadinRequest request) {
         private static VaadinSession findOrcreateSession() {
             VaadinSession session = VaadinSession.getCurrent();
             if (session == null) {
+                DeploymentConfiguration conf = Mockito.mock(DeploymentConfiguration.class);
                 session = new AlwaysLockedVaadinSession(
-                        new VaadinServletService(new VaadinServlet(), null));
+                        new VaadinServletService(new VaadinServlet(), conf));
                 VaadinSession.setCurrent(session);
             }
             return session;

flow-server/src/main/java/com/vaadin/flow/server/VaadinServlet.java

@@ -23,6 +23,9 @@
 import java.util.Optional;
 import java.util.Properties;
 
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
 import com.vaadin.flow.component.UI;
 import com.vaadin.flow.di.Lookup;
 import com.vaadin.flow.function.DeploymentConfiguration;
@@ -34,6 +37,7 @@
 import com.vaadin.flow.shared.JsonConstants;
 import com.vaadin.pro.licensechecker.BuildType;
 import com.vaadin.pro.licensechecker.LicenseChecker;
+import com.vaadin.pro.licensechecker.LicenseException;
 
 /**
  * The main servlet, which handles all incoming requests to the application.
@@ -50,6 +54,9 @@
  * @since 1.0
  */
 public class VaadinServlet extends HttpServlet {
+
+    private static final String PROJECT_NAME = "flow";
+
     private VaadinServletService servletService;
     private StaticFileHandler staticFileHandler;
     private WebJarServer webJarServer;
@@ -95,9 +102,20 @@ public void init(ServletConfig servletConfig) throws ServletException {
     }
 
     private void verifyLicense(boolean productionMode) {
-        if (!productionMode) {
-            String flowVersion = Version.getFullVersion();
-            LicenseChecker.checkLicense("flow", flowVersion,
+        String frameworkVersion = Version.getFullVersion();
+        if (productionMode) {
+            try {
+                LicenseChecker.checkLicense(PROJECT_NAME, frameworkVersion,
+                        BuildType.PRODUCTION, null);
+            } catch (LicenseException e) {
+                getLogger().error(
+                        "This Vaadin version requires an extended maintenance subscription."
+                                + "Provide either a server key or an online license checking key,"
+                                + "which you can get from: https://vaadin.com/myaccount/licenses#latest.",
+                        e);
+            }
+        } else {
+            LicenseChecker.checkLicense(PROJECT_NAME, frameworkVersion,
                     BuildType.DEVELOPMENT);
         }
     }
@@ -565,4 +583,8 @@ public void init() {
             }
         }
     }
+
+    private static Logger getLogger() {
+        return LoggerFactory.getLogger(VaadinServlet.class.getName());
+    }
 }

flow-server/src/test/java/com/vaadin/flow/server/VaadinServletTest.java

@@ -26,6 +26,7 @@
 import com.vaadin.flow.server.MockServletServiceSessionSetup.TestVaadinServletResponse;
 import com.vaadin.pro.licensechecker.BuildType;
 import com.vaadin.pro.licensechecker.LicenseChecker;
+import com.vaadin.pro.licensechecker.LicenseException;
 
 import net.jcip.annotations.NotThreadSafe;
 
@@ -121,11 +122,27 @@ public void checkLicense_devMode_licenseIsChecked()
     }
 
     @Test
-    public void checkLicense_prodMode_licenseIsNotChecked()
+    public void checkLicense_prodMode_licenseIsChecked()
             throws ServletException {
         Mockito.when(configuration.isProductionMode()).thenReturn(true);
         triggerLicenseChecking();
-        licenseChecker.verifyNoInteractions();
+        licenseChecker.verify(() -> LicenseChecker.checkLicense("flow",
+                Version.getFullVersion(), BuildType.PRODUCTION, null));
+    }
+
+    @Test
+    public void checkLicense_prodModeCheck_notFails()
+            throws ServletException {
+        licenseChecker
+                .when(() -> LicenseChecker.checkLicense("flow",
+                        Version.getFullVersion(), BuildType.PRODUCTION, null))
+                .thenThrow(new LicenseException("Test exception"));
+        try {
+            triggerLicenseChecking();
+        } catch (LicenseException e) {
+            Assert.fail(
+                    "License check should not throw exception in prod mode");
+        }
     }
 
     private HttpServletRequest createRequest(
@@ -181,4 +198,4 @@ protected DeploymentConfiguration createDeploymentConfiguration() {
             return configuration;
         }
     }
-}
+}