Allow resoving theme resources from flat classpath (#10989)

Closes #10951

quarkus/deployment/src/main/java/org/keycloak/quarkus/deployment/KeycloakProcessor.java

@@ -127,11 +127,14 @@ import io.quarkus.deployment.builditem.FeatureBuildItem;
 import io.quarkus.vertx.http.deployment.FilterBuildItem;
 
 import org.keycloak.quarkus.runtime.storage.database.jpa.NamedJpaConnectionProviderFactory;
+import org.keycloak.quarkus.runtime.themes.FlatClasspathThemeResourceProviderFactory;
 import org.keycloak.representations.provider.ScriptProviderDescriptor;
 import org.keycloak.representations.provider.ScriptProviderMetadata;
 import org.keycloak.quarkus.runtime.integration.web.NotFoundHandler;
 import org.keycloak.services.ServicesLogger;
+import org.keycloak.theme.ClasspathThemeResourceProviderFactory;
 import org.keycloak.theme.FolderThemeProviderFactory;
+import org.keycloak.theme.ThemeResourceSpi;
 import org.keycloak.transaction.JBossJtaTransactionManagerLookup;
 import org.keycloak.quarkus.runtime.Environment;
 import org.keycloak.url.DefaultHostnameProviderFactory;
@@ -160,7 +163,8 @@ class KeycloakProcessor {
             FixedHostnameProviderFactory.class,
             RequestHostnameProviderFactory.class,
             FilesPlainTextVaultProviderFactory.class,
-            BlacklistPasswordPolicyProviderFactory.class);
+            BlacklistPasswordPolicyProviderFactory.class,
+            ClasspathThemeResourceProviderFactory.class);
 
     static {
         DEPLOYEABLE_SCRIPT_PROVIDERS.put(AUTHENTICATORS, KeycloakProcessor::registerScriptAuthenticator);
@@ -288,6 +292,10 @@ class KeycloakProcessor {
             if (spi instanceof JpaConnectionSpi) {
                 configureUserDefinedPersistenceUnits(descriptors, factories, preConfiguredProviders, spi);
             }
+
+            if (spi instanceof ThemeResourceSpi) {
+                configureThemeResourceProviders(factories, spi);
+            }
         }
 
         recorder.configSessionFactory(factories, defaultProviders, preConfiguredProviders, Environment.isRebuild());
@@ -295,6 +303,20 @@ class KeycloakProcessor {
         return new KeycloakSessionFactoryPreInitBuildItem();
     }
 
+    private void configureThemeResourceProviders(Map<Spi, Map<Class<? extends Provider>, Map<String, Class<? extends ProviderFactory>>>> factories, Spi spi) {
+        try {
+            ClassLoader classLoader = Thread.currentThread().getContextClassLoader();
+            Enumeration<URL> resources = classLoader.getResources(FlatClasspathThemeResourceProviderFactory.THEME_RESOURCES);
+
+            if (resources.hasMoreElements()) {
+                // make sure theme resources are loaded using a flat classpath. if no resources are available the provider is not registered
+                factories.computeIfAbsent(spi, key -> new HashMap<>()).computeIfAbsent(spi.getProviderClass(), aClass -> new HashMap<>()).put(FlatClasspathThemeResourceProviderFactory.ID, FlatClasspathThemeResourceProviderFactory.class);
+            }
+        } catch (Exception e) {
+            throw new RuntimeException("Failed to install default theme resource provider", e);
+        }
+    }
+
     private void configureUserDefinedPersistenceUnits(List<PersistenceXmlDescriptorBuildItem> descriptors,
             Map<Spi, Map<Class<? extends Provider>, Map<String, Class<? extends ProviderFactory>>>> factories,
             Map<String, ProviderFactory> preConfiguredProviders, Spi spi) {

quarkus/runtime/src/main/java/org/keycloak/quarkus/runtime/themes/FlatClasspathThemeResourceProviderFactory.java

@@ -0,0 +1,49 @@
+/*
+ * Copyright 2022 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.themes;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.net.URL;
+import java.util.Enumeration;
+import org.keycloak.theme.ClasspathThemeResourceProviderFactory;
+
+public class FlatClasspathThemeResourceProviderFactory extends ClasspathThemeResourceProviderFactory {
+
+    public static final String ID = "flat-classpath";
+
+    @Override
+    public InputStream getResourceAsStream(String path) throws IOException {
+        Enumeration<URL> resources = classLoader.getResources(THEME_RESOURCES_RESOURCES);
+
+        while (resources.hasMoreElements()) {
+            InputStream is = getResourceAsStream(path, resources.nextElement());
+
+            if (is != null) {
+                return is;
+            }
+        }
+
+        return null;
+    }
+
+    @Override
+    public String getId() {
+        return ID;
+    }
+}

services/src/main/java/org/keycloak/theme/ClasspathThemeResourceProviderFactory.java

@@ -15,12 +15,13 @@ import org.keycloak.models.KeycloakSessionFactory;
 
 public class ClasspathThemeResourceProviderFactory implements ThemeResourceProviderFactory, ThemeResourceProvider {
 
-    public static final String THEME_RESOURCES_TEMPLATES = "theme-resources/templates/";
-    public static final String THEME_RESOURCES_RESOURCES = "theme-resources/resources/";
-    public static final String THEME_RESOURCES_MESSAGES = "theme-resources/messages/";
+    public static final String THEME_RESOURCES = "theme-resources";
+    public static final String THEME_RESOURCES_TEMPLATES = THEME_RESOURCES + "/templates/";
+    public static final String THEME_RESOURCES_RESOURCES = THEME_RESOURCES + "/resources/";
+    public static final String THEME_RESOURCES_MESSAGES = THEME_RESOURCES + "/messages/";
 
     private final String id;
-    private final ClassLoader classLoader;
+    protected final ClassLoader classLoader;
 
     public ClasspathThemeResourceProviderFactory() {
         this("classpath", Thread.currentThread().getContextClassLoader());
@@ -43,7 +44,10 @@ public class ClasspathThemeResourceProviderFactory implements ThemeResourceProvi
 
     @Override
     public InputStream getResourceAsStream(String path) throws IOException {
-        final URL rootResourceURL = classLoader.getResource(THEME_RESOURCES_RESOURCES);
+        return getResourceAsStream(path, classLoader.getResource(THEME_RESOURCES_RESOURCES));
+    }
+
+    protected InputStream getResourceAsStream(String path, URL rootResourceURL) throws IOException {
         if (rootResourceURL == null) {
             return null;
         }