Removing custom classloader and allow loading drivers at runtime

Closes #13205

Co-authored-by: Brett Lounsbury <brett.lounsbury@nasdaq.com>

docs/guides/server/db.adoc

@@ -57,6 +57,19 @@ The following is a sample command for a PostgreSQL database.
 
 Be aware that you need to escape characters when invoking commands containing special shell characters such as `;` using the CLI, so you might want to set it in the configuration file instead.
 
+== Overriding the default JDBC driver
+
+The server uses a default JDBC driver accordingly to the database you chose.
+
+To set a different driver you can set the `db-driver` with the fully qualified class name of the JDBC driver:
+
+<@kc.start parameters="--db postgres --db-driver=my.Driver"/>
+
+Regardless of the driver you set, the default driver is always available at runtime.
+
+Only set this property if you really need to. For instance, when leveraging the capabilities from a JDBC Driver Wrapper for
+a specific cloud database service.
+
 == Configuring Unicode support for the database
 
 Unicode support for all fields depends on whether the database allows VARCHAR and CHAR fields to use the Unicode character set.

quarkus/config-api/src/main/java/org/keycloak/config/DatabaseOptions.java

@@ -12,8 +12,7 @@ public class DatabaseOptions {
 
     public static final Option<String> DB_DRIVER = new OptionBuilder<>("db-driver", String.class)
             .category(OptionCategory.DATABASE)
-            .hidden()
-            .defaultValue(Database.getDriver("dev-file", true).get())
+            .description("The fully qualified class name of the JDBC driver. If not set, a default driver is set accordingly to the chosen database.")
             .build();
 
     public static final Option<String> DB = new OptionBuilder<>("db", String.class)

quarkus/runtime/src/main/java/org/keycloak/quarkus/runtime/KeycloakClassLoader.java

@@ -1,42 +0,0 @@
-/*
- * Copyright 2021 Red Hat, Inc. and/or its affiliates
- * and other contributors as indicated by the @author tags.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- * http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package org.keycloak.quarkus.runtime;
-
-import java.io.IOException;
-import java.net.URL;
-import java.sql.Driver;
-import java.util.Collections;
-import java.util.Enumeration;
-
-public class KeycloakClassLoader extends ClassLoader {
-
-    KeycloakClassLoader() {
-        super(Thread.currentThread().getContextClassLoader());
-    }
-
-    @Override
-    public Enumeration<URL> getResources(String name) throws IOException {
-        // drivers are going to be loaded lazily, and we avoid loading all available drivers
-        // see https://github.com/quarkusio/quarkus/pull/7089
-        if (name.contains(Driver.class.getName())) {
-            return Collections.emptyEnumeration();
-        }
-
-        return super.getResources(name);
-    }
-}

quarkus/runtime/src/main/java/org/keycloak/quarkus/runtime/KeycloakMain.java

@@ -94,11 +94,7 @@ public class KeycloakMain implements QuarkusApplication {
     }
 
     public static void start(ExecutionExceptionHandler errorHandler, PrintWriter errStream, String[] args) {
-        ClassLoader originalCl = Thread.currentThread().getContextClassLoader();
-
         try {
-            Thread.currentThread().setContextClassLoader(new KeycloakClassLoader());
-
             Quarkus.run(KeycloakMain.class, (exitCode, cause) -> {
                 if (cause != null) {
                     errorHandler.error(errStream,
@@ -117,8 +113,6 @@ public class KeycloakMain implements QuarkusApplication {
                     String.format("Unexpected error when starting the server in (%s) mode", getKeycloakModeFromProfile(getProfileOrDefault("prod"))),
                     cause.getCause());
             System.exit(1);
-        } finally {
-            Thread.currentThread().setContextClassLoader(originalCl);
         }
     }
 

quarkus/runtime/src/main/java/org/keycloak/quarkus/runtime/configuration/mappers/DatabasePropertyMappers.java

@@ -34,6 +34,7 @@ final class DatabasePropertyMappers {
                         .mapFrom("db")
                         .to("quarkus.datasource.jdbc.driver")
                         .transformer(DatabasePropertyMappers::getXaOrNonXaDriver)
+                        .paramLabel("driver")
                         .build(),
                 fromOption(DatabaseOptions.DB)
                         .transformer(DatabasePropertyMappers::resolveDatabaseVendor)

quarkus/tests/integration/src/test/java/org/keycloak/it/cli/OptionValidationTest.java

@@ -59,7 +59,7 @@ public class OptionValidationTest {
     public void failUnknownOptionWhitespaceSeparatorNotShowingValue(LaunchResult result) {
         CLIResult cliResult = (CLIResult) result;
         assertEquals("Unknown option: '--db-pasword'\n" +
-                "Possible solutions: --db-url, --db-url-host, --db-url-database, --db-url-port, --db-url-properties, --db-username, --db-password, --db-schema, --db-pool-initial-size, --db-pool-min-size, --db-pool-max-size, --db\n" +
+                "Possible solutions: --db-driver, --db-url, --db-url-host, --db-url-database, --db-url-port, --db-url-properties, --db-username, --db-password, --db-schema, --db-pool-initial-size, --db-pool-min-size, --db-pool-max-size, --db\n" +
                 "Try '" + KeycloakDistribution.SCRIPT_CMD + " start --help' for more information on the available options.", cliResult.getErrorOutput());
     }
 
@@ -68,7 +68,7 @@ public class OptionValidationTest {
     public void failUnknownOptionEqualsSeparatorNotShowingValue(LaunchResult result) {
         CLIResult cliResult = (CLIResult) result;
         assertEquals("Unknown option: '--db-pasword'\n" +
-                "Possible solutions: --db-url, --db-url-host, --db-url-database, --db-url-port, --db-url-properties, --db-username, --db-password, --db-schema, --db-pool-initial-size, --db-pool-min-size, --db-pool-max-size, --db\n" +
+                "Possible solutions: --db-driver, --db-url, --db-url-host, --db-url-database, --db-url-port, --db-url-properties, --db-username, --db-password, --db-schema, --db-pool-initial-size, --db-pool-min-size, --db-pool-max-size, --db\n" +
                 "Try '" + KeycloakDistribution.SCRIPT_CMD + " start --help' for more information on the available options.", cliResult.getErrorOutput());
     }
 
@@ -77,7 +77,7 @@ public class OptionValidationTest {
     public void failWithFirstOptionOnMultipleUnknownOptions(LaunchResult result) {
         CLIResult cliResult = (CLIResult) result;
         assertEquals("Unknown option: '--db-pasword'\n" +
-                "Possible solutions: --db-url, --db-url-host, --db-url-database, --db-url-port, --db-url-properties, --db-username, --db-password, --db-schema, --db-pool-initial-size, --db-pool-min-size, --db-pool-max-size, --db\n" +
+                "Possible solutions: --db-driver, --db-url, --db-url-host, --db-url-database, --db-url-port, --db-url-properties, --db-username, --db-password, --db-schema, --db-pool-initial-size, --db-pool-min-size, --db-pool-max-size, --db\n" +
                 "Try '" + KeycloakDistribution.SCRIPT_CMD + " start --help' for more information on the available options.", cliResult.getErrorOutput());
     }
 }