feat(mail): add startup checks for mail configuration IQSS#7424

During the deployment of Dataverse we check for conditions of the mail system that might not be done as people intend to use it.
We'll only issue warnings in the log messages, nothing critical here.

Author: poikilotherm

src/main/java/edu/harvard/iq/dataverse/settings/ConfigCheckService.java

@@ -1,16 +1,22 @@
 package edu.harvard.iq.dataverse.settings;
 
+import edu.harvard.iq.dataverse.MailServiceBean;
+import edu.harvard.iq.dataverse.settings.SettingsServiceBean.Key;
 import edu.harvard.iq.dataverse.util.FileUtil;
-
+import edu.harvard.iq.dataverse.util.MailSessionProducer;
 import jakarta.annotation.PostConstruct;
 import jakarta.ejb.DependsOn;
 import jakarta.ejb.Singleton;
 import jakarta.ejb.Startup;
+import jakarta.inject.Inject;
+import jakarta.mail.internet.InternetAddress;
+
 import java.io.IOException;
 import java.nio.file.FileSystemException;
 import java.nio.file.Files;
 import java.nio.file.Path;
 import java.util.Map;
+import java.util.Optional;
 import java.util.logging.Level;
 import java.util.logging.Logger;
 
@@ -20,6 +26,11 @@
 public class ConfigCheckService {
 
     private static final Logger logger = Logger.getLogger(ConfigCheckService.class.getCanonicalName());
+    
+    @Inject
+    MailSessionProducer mailSessionProducer;
+    @Inject
+    MailServiceBean mailService;
 
     public static class ConfigurationError extends RuntimeException {
         public ConfigurationError(String message) {
@@ -32,6 +43,9 @@ public void startup() {
         if (!checkSystemDirectories()) {
             throw new ConfigurationError("Not all configuration checks passed successfully. See logs above.");
         }
+        
+        // Only checks resulting in warnings, nothing critical that needs to stop deployment
+        checkSystemMailSetup();
     }
 
     /**
@@ -77,5 +91,36 @@ public boolean checkSystemDirectories() {
         }
         return success;
     }
+    
+    /**
+     * This method is not expected to make a deployment fail, but send out clear warning messages about missing or
+     * wrong configuration settings.
+     */
+    public void checkSystemMailSetup() {
+        // Check if a system mail setting has been provided or issue warning about disabled mail notifications
+        Optional<InternetAddress> mailAddress = mailService.getSystemAddress();
+        
+        // Not present -> warning
+        if (mailAddress.isEmpty()) {
+            logger.warning("Could not find a system mail setting in database (key :" + Key.SystemEmail + ", deprecated) or JVM option '" + JvmSettings.SYSTEM_EMAIL.getScopedKey() + "'");
+            logger.warning("Mail notifications and system messages are deactivated until you provide a configuration");
+        }
+        
+        // If there is an app server provided mail config, let's determine if the setup is matching
+        // TODO: when support for appserver provided mail session goes away, this code can be deleted
+        if (mailSessionProducer.hasSessionFromAppServer()) {
+            if (mailAddress.isEmpty()) {
+                logger.warning("Found a mail session provided by app server, but no system mail address (see logs above)");
+            // Check if the "from" in the session is the same as the system mail address (see issue 4210)
+            } else {
+                String sessionFrom = mailSessionProducer.getSession().getProperty("mail.from");
+                if (! mailAddress.get().toString().equals(sessionFrom)) {
+                    logger.warning(() -> String.format(
+                        "Found app server mail session provided 'from' (%s) does not match system mail setting (%s)",
+                        sessionFrom, mailAddress.get()));
+                }
+            }
+        }
+    }
 
 }