Load mirth.properties.d drop-in configuration overrides on startup

server/conf/mirth.properties

@@ -1,4 +1,8 @@
 # Mirth Connect configuration file
+#
+# Put local customizations in files under conf/mirth.properties.d instead of
+# editing this file, so a new release's mirth.properties can be dropped in
+# without hand-merging. See conf/mirth.properties.d/mirth.properties.example.
 
 # directories
 dir.appdata = appdata

server/conf/mirth.properties.d/mirth.properties.example

@@ -0,0 +1,21 @@
+# Copy this file to a name ending in .properties (for example 10-local.properties)
+# to activate it. Files in this directory named *.properties are loaded on top of
+# conf/mirth.properties at startup, in lexical filename order: later files
+# override earlier ones, and any file here overrides mirth.properties itself.
+#
+# Keeping customizations here instead of in mirth.properties means an upgrade
+# can replace mirth.properties without hand-merging your changes back in.
+#
+# Exception: database.password and database-readonly.password are encrypted in
+# place in mirth.properties; a value here stays plaintext. keystore.storepass
+# and keystore.keypass are auto-generated on first boot only when BOTH are
+# still the shipped defaults - overriding just one here leaves the other at
+# its published default. Leave these four in mirth.properties.
+#
+# Files are parsed with java.util.Properties semantics. If a key appears more
+# than once, the last occurrence wins; there are no multi-valued properties. For
+# list properties such as https.client.protocols, use a single comma-separated
+# value.
+
+# http.port = 8081
+# https.port = 8444

server/src/main/java/com/mirth/connect/server/Mirth.java

@@ -59,6 +59,7 @@
 import com.mirth.connect.server.controllers.MigrationController;
 import com.mirth.connect.server.controllers.ScriptController;
 import com.mirth.connect.server.controllers.UsageController;
+import com.mirth.connect.server.extprops.DropInProperties;
 import com.mirth.connect.server.controllers.UserController;
 import com.mirth.connect.server.logging.JuliToLog4JService;
 import com.mirth.connect.server.logging.LogOutputStream;
@@ -187,7 +188,10 @@ public boolean initResources() {
         try {
             mirthPropertiesStream = ResourceUtil.getResourceStream(this.getClass(), "mirth.properties");
             mirthProperties = PropertiesConfigurationUtil.create(mirthPropertiesStream);
+            mirthProperties = DropInProperties.overlay(mirthProperties, ResourceUtil.getMirthPropertiesDropInDirectory());
         } catch (Exception e) {
+            // Reset so a failed drop-in overlay aborts startup instead of booting with a partial configuration
+            mirthProperties = PropertiesConfigurationUtil.create();
             logger.error("could not load mirth.properties", e);
         } finally {
             IOUtils.closeQuietly(mirthPropertiesStream);

server/src/main/java/com/mirth/connect/server/controllers/DefaultConfigurationController.java

@@ -119,6 +119,7 @@
 import com.mirth.connect.plugins.directoryresource.DirectoryResourceProperties;
 import com.mirth.connect.server.ExtensionLoader;
 import com.mirth.connect.server.mybatis.KeyValuePair;
+import com.mirth.connect.server.extprops.DropInProperties;
 import com.mirth.connect.server.tools.ClassPathResource;
 import com.mirth.connect.server.util.DatabaseUtil;
 import com.mirth.connect.server.util.PasswordRequirementsChecker;
@@ -166,6 +167,9 @@ public class DefaultConfigurationController extends ConfigurationController {
     private static PropertiesConfiguration versionConfig = PropertiesConfigurationUtil.create();
     private static FileBasedConfigurationBuilder<PropertiesConfiguration> mirthConfigBuilder = PropertiesConfigurationUtil.createBuilder();
     protected static PropertiesConfiguration mirthConfig = PropertiesConfigurationUtil.create();
+    // The file-backed configuration that saveMirthConfig() writes. Kept separate from mirthConfig
+    // so that values from mirth.properties.d drop-in files are never baked into mirth.properties.
+    protected static PropertiesConfiguration mirthFileConfig = mirthConfig;
     private static EncryptionSettings encryptionConfig;
     private static DatabaseSettings databaseConfig;
     private static String apiBypassword;
@@ -229,15 +233,19 @@ public void initialize() {
         try {
             // Delimiter parsing disabled by default so getString() returns the whole property, even if there are commas
             mirthConfigBuilder = PropertiesConfigurationUtil.createBuilder(new File(ClassPathResource.getResourceURI("mirth.properties")));
-            mirthConfig = mirthConfigBuilder.getConfiguration();
+            mirthFileConfig = mirthConfigBuilder.getConfiguration();
+            // Also assign the read view now so anything reading during migration sees real values
+            mirthConfig = mirthFileConfig;
 
-            MigrationController.getInstance().migrateConfiguration(mirthConfig);
+            MigrationController.getInstance().migrateConfiguration(mirthFileConfig);
             try {
                 mirthConfigBuilder.save();
             } catch (ConfigurationException e) {
                 logger.error("Unable to update mirth.properties version during migration.", e);
             }
 
+            mirthConfig = DropInProperties.overlay(mirthFileConfig, ResourceUtil.getMirthPropertiesDropInDirectory());
+
             // load the server version
             versionPropertiesStream = ResourceUtil.getResourceStream(this.getClass(), "version.properties");
             versionConfig = PropertiesConfigurationUtil.create(versionPropertiesStream);
@@ -1245,11 +1253,11 @@ public void initializeSecuritySettings() {
                  */
                 if (Arrays.equals(keyStorePassword, DEFAULT_STOREPASS.toCharArray()) && Arrays.equals(keyPassword, DEFAULT_STOREPASS.toCharArray())) {
                     String keyStorePasswordStr = generateNewPassword();
-                    mirthConfig.setProperty("keystore.storepass", keyStorePasswordStr);
+                    setMirthConfigProperty("keystore.storepass", keyStorePasswordStr);
                     keyStorePassword = keyStorePasswordStr.toCharArray();
 
                     String keyPasswordStr = generateNewPassword();
-                    mirthConfig.setProperty("keystore.keypass", keyPasswordStr);
+                    setMirthConfigProperty("keystore.keypass", keyPasswordStr);
                     keyPassword = keyPasswordStr.toCharArray();
 
                     saveMirthConfig();
@@ -1329,18 +1337,26 @@ private void updateDatabasePassword(Encryptor encryptor, String password, boolea
 
             if (!StringUtils.startsWith(encryptedPassword, "{")) {
                 // Re-encrypt if still using the old-style format
-                mirthConfig.setProperty(readOnly ? DatabaseConstants.DATABASE_READONLY_PASSWORD : DatabaseConstants.DATABASE_PASSWORD, EncryptionSettings.ENCRYPTION_PREFIX + encryptor.encrypt(decryptedPassword));
+                setMirthConfigProperty(readOnly ? DatabaseConstants.DATABASE_READONLY_PASSWORD : DatabaseConstants.DATABASE_PASSWORD, EncryptionSettings.ENCRYPTION_PREFIX + encryptor.encrypt(decryptedPassword));
                 saveMirthConfig();
             }
         } else if (StringUtils.isNotBlank(password)) {
             // encrypt the password and write it back to the file
             String encryptedPassword = EncryptionSettings.ENCRYPTION_PREFIX + encryptor.encrypt(password);
-            mirthConfig.setProperty(readOnly ? DatabaseConstants.DATABASE_READONLY_PASSWORD : DatabaseConstants.DATABASE_PASSWORD, encryptedPassword);
+            setMirthConfigProperty(readOnly ? DatabaseConstants.DATABASE_READONLY_PASSWORD : DatabaseConstants.DATABASE_PASSWORD, encryptedPassword);
 
             saveMirthConfig();
         }
     }
 
+    private void setMirthConfigProperty(String key, Object value) {
+        mirthConfig.setProperty(key, value);
+
+        if (mirthFileConfig != mirthConfig) {
+            mirthFileConfig.setProperty(key, value);
+        }
+    }
+
     private void saveMirthConfig() throws FileNotFoundException, ConfigurationException {
         /*
          * Save using a FileOutputStream so that the file will be saved to the proper location, even
@@ -1350,7 +1366,7 @@ private void saveMirthConfig() throws FileNotFoundException, ConfigurationExcept
         OutputStream os = new FileOutputStream(new File(confDir, "mirth.properties"));
 
         try {
-            PropertiesConfigurationUtil.saveTo(mirthConfig, os);
+            PropertiesConfigurationUtil.saveTo(mirthFileConfig, os);
         } finally {
             ResourceUtil.closeResourceQuietly(os);
         }

server/src/main/java/com/mirth/connect/server/extprops/DropInProperties.java

@@ -0,0 +1,111 @@
+/*
+ * Copyright (c) Mirth Corporation. All rights reserved.
+ *
+ * http://www.mirthcorp.com
+ *
+ * The software in this package is published under the terms of the MPL license a copy of which has
+ * been included with this distribution in the LICENSE.txt file.
+ */
+
+package com.mirth.connect.server.extprops;
+
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.util.Arrays;
+import java.util.Properties;
+
+import org.apache.commons.configuration2.ConfigurationUtils;
+import org.apache.commons.configuration2.PropertiesConfiguration;
+import org.apache.commons.configuration2.ex.ConfigurationException;
+
+/**
+ * Applies drop-in override files from a mirth.properties.d directory on top of an already-loaded
+ * configuration. Files directly under the directory whose names end in ".properties" are applied
+ * in lexical filename order: later files override earlier ones, and all of them override the base
+ * configuration. Merge semantics come from java.util.Properties.load(), where the last occurrence
+ * of a key wins.
+ *
+ * This class lives in the extprops package because it is shared by the launcher jar and the server
+ * jar, and must not reference classes outside this package and the launcher's classpath.
+ */
+public class DropInProperties {
+
+    /**
+     * Loads drop-in files into the given properties, overriding any existing values. Files that
+     * cannot be read are logged and skipped.
+     */
+    public static void load(Properties properties, File dropInDir, LoggerWrapper logger) {
+        File[] files = listDropInFiles(dropInDir);
+
+        if (files == null) {
+            if (isUnlistableDirectory(dropInDir)) {
+                logger.error("Unable to list drop-in properties directory: " + dropInDir.getPath());
+            }
+            return;
+        }
+
+        for (File file : files) {
+            try (InputStream is = new FileInputStream(file)) {
+                properties.load(is);
+            } catch (IOException e) {
+                logger.error("Unable to read drop-in properties file: " + file.getPath(), e);
+            }
+        }
+    }
+
+    /**
+     * Returns a configuration with any drop-in files applied on top of the given base
+     * configuration. The base configuration is never modified; it is returned as-is when there are
+     * no drop-in files.
+     */
+    public static PropertiesConfiguration overlay(PropertiesConfiguration base, File dropInDir) throws ConfigurationException {
+        File[] files = listDropInFiles(dropInDir);
+
+        if (files == null) {
+            if (isUnlistableDirectory(dropInDir)) {
+                throw new ConfigurationException("Unable to list drop-in properties directory: " + dropInDir.getPath());
+            }
+            return base;
+        }
+
+        if (files.length == 0) {
+            return base;
+        }
+
+        Properties dropIns = new Properties();
+
+        for (File file : files) {
+            try (InputStream is = new FileInputStream(file)) {
+                dropIns.load(is);
+            } catch (IOException e) {
+                throw new ConfigurationException("Unable to read drop-in properties file: " + file.getPath(), e);
+            }
+        }
+
+        PropertiesConfiguration merged = new PropertiesConfiguration();
+        ConfigurationUtils.copy(base, merged);
+
+        for (String key : dropIns.stringPropertyNames()) {
+            merged.setProperty(key, dropIns.getProperty(key));
+        }
+
+        return merged;
+    }
+
+    private static File[] listDropInFiles(File dropInDir) {
+        File[] files = dropInDir == null ? null : dropInDir.listFiles(file -> file.isFile() && file.getName().endsWith(".properties"));
+
+        if (files != null) {
+            Arrays.sort(files);
+        }
+
+        return files;
+    }
+
+    /** listFiles() returns null both for a missing directory and an unlistable one; only the latter deserves noise. */
+    private static boolean isUnlistableDirectory(File dropInDir) {
+        return dropInDir != null && dropInDir.isDirectory();
+    }
+}

server/src/main/java/com/mirth/connect/server/extprops/ExtensionStatuses.java

@@ -55,6 +55,7 @@ private ExtensionStatuses() {
             } finally {
                 IOUtils.closeQuietly(is);
             }
+            DropInProperties.load(mirthProperties, new File("./conf/mirth.properties.d"), logger);
         } catch (Exception e) {
             logger.error("Unable to read mirth.properties.", e);
         }

server/src/main/java/com/mirth/connect/server/launcher/MirthLauncher.java

@@ -33,6 +33,7 @@
 import org.w3c.dom.Element;
 import org.w3c.dom.NodeList;
 
+import com.mirth.connect.server.extprops.DropInProperties;
 import com.mirth.connect.server.extprops.ExtensionStatuses;
 import com.mirth.connect.server.extprops.LoggerWrapper;
 
@@ -77,6 +78,7 @@ public static void main(String[] args) {
 
             try (FileInputStream inputStream = new FileInputStream(new File(MIRTH_PROPERTIES_FILE))) {
                 mirthProperties.load(inputStream);
+                DropInProperties.load(mirthProperties, new File(MIRTH_PROPERTIES_FILE + ".d"), logger);
                 includeCustomLib = mirthProperties.getProperty(PROPERTY_INCLUDE_CUSTOM_LIB);
                 createAppdataDir(mirthProperties);
             } catch (Exception e) {

server/src/main/java/com/mirth/connect/server/servlets/WebStartServlet.java

@@ -49,6 +49,7 @@
 import com.mirth.connect.server.controllers.ConfigurationController;
 import com.mirth.connect.server.controllers.ControllerFactory;
 import com.mirth.connect.server.controllers.ExtensionController;
+import com.mirth.connect.server.extprops.DropInProperties;
 import com.mirth.connect.server.tools.ClassPathResource;
 import com.mirth.connect.server.util.ResourceUtil;
 import com.mirth.connect.util.MirthSSLUtil;
@@ -363,8 +364,9 @@ protected PropertiesConfiguration getMirthProperties() throws FileNotFoundExcept
 
         InputStream mirthPropsIs = null;
         try {
-            mirthPropsIs = ResourceUtil.getResourceStream(getClass(), "mirth.properties"); 
+            mirthPropsIs = ResourceUtil.getResourceStream(getClass(), "mirth.properties");
             mirthProperties = PropertiesConfigurationUtil.create(mirthPropsIs);
+            mirthProperties = DropInProperties.overlay(mirthProperties, ResourceUtil.getMirthPropertiesDropInDirectory());
         } finally {
             ResourceUtil.closeResourceQuietly(mirthPropsIs);
         }

server/src/main/java/com/mirth/connect/server/util/ResourceUtil.java

@@ -10,12 +10,31 @@
 package com.mirth.connect.server.util;
 
 import java.io.Closeable;
+import java.io.File;
 import java.io.FileInputStream;
 import java.io.FileNotFoundException;
 import java.io.IOException;
 import java.io.InputStream;
+import java.net.URI;
+
+import com.mirth.connect.server.tools.ClassPathResource;
 
 public class ResourceUtil {
+
+    /**
+     * Returns the mirth.properties.d drop-in directory next to the mirth.properties resolved from
+     * the classpath, or null when mirth.properties does not resolve to a file on disk.
+     */
+    public static File getMirthPropertiesDropInDirectory() {
+        URI uri = ClassPathResource.getResourceURI("mirth.properties");
+
+        if (uri != null && "file".equals(uri.getScheme())) {
+            return new File(new File(uri).getParentFile(), "mirth.properties.d");
+        }
+
+        return null;
+    }
+
     /**
      * Returns a resource as a stream by checking:
      * 

server/src/main/java/com/mirth/connect/server/util/javascript/JavaScriptScopeUtil.java

@@ -33,6 +33,8 @@
 import com.mirth.connect.donkey.model.message.Message;
 import com.mirth.connect.donkey.model.message.RawMessage;
 import com.mirth.connect.server.controllers.ConfigurationController;
+import com.mirth.connect.server.extprops.DropInProperties;
+import com.mirth.connect.server.extprops.LoggerWrapper;
 import com.mirth.connect.server.transformers.InvalidTransformedDataException;
 import com.mirth.connect.server.userutil.AlertSender;
 import com.mirth.connect.server.userutil.Attachment;
@@ -44,6 +46,7 @@
 import com.mirth.connect.server.userutil.VMRouter;
 import com.mirth.connect.server.util.GlobalChannelVariableStoreFactory;
 import com.mirth.connect.server.util.GlobalVariableStore;
+import com.mirth.connect.server.util.ResourceUtil;
 import com.mirth.connect.server.util.TemplateValueReplacer;
 import com.mirth.connect.userutil.ImmutableConnectorMessage;
 import com.mirth.connect.userutil.ImmutableMessage;
@@ -62,6 +65,7 @@ public class JavaScriptScopeUtil {
          * it in interpretive mode. See MIRTH-1627 for more information.
          */
         Properties properties = PropertyLoader.loadProperties("mirth");
+        DropInProperties.load(properties, ResourceUtil.getMirthPropertiesDropInDirectory(), new LoggerWrapper(logger));
 
         if (MapUtils.isNotEmpty(properties) && properties.containsKey("rhino.optimizationlevel")) {
             logger.debug("set Rhino context optimization level: " + rhinoOptimizationLevel);