refactor: move configuration loading logic out of the extension context

DEPENDENCIES

@@ -1,4 +1,4 @@
 maven/mavencentral/com.apicatalog/carbon-did/0.3.0, Apache-2.0, approved, clearlydefined
 maven/mavencentral/com.apicatalog/copper-multibase/0.5.0, Apache-2.0, approved, #14501
 maven/mavencentral/com.apicatalog/copper-multicodec/0.1.1, Apache-2.0, approved, #14500
 maven/mavencentral/com.apicatalog/iron-ed25519-cryptosuite-2020/0.14.0, Apache-2.0, approved, #14503
@@ -16,27 +16,34 @@
 maven/mavencentral/com.fasterxml.jackson.core/jackson-annotations/2.14.1, Apache-2.0, approved, #5303
 maven/mavencentral/com.fasterxml.jackson.core/jackson-annotations/2.15.1, Apache-2.0, approved, #7947
 maven/mavencentral/com.fasterxml.jackson.core/jackson-annotations/2.17.0, Apache-2.0, approved, #13672
+maven/mavencentral/com.fasterxml.jackson.core/jackson-annotations/2.17.1, Apache-2.0, approved, #13672
 maven/mavencentral/com.fasterxml.jackson.core/jackson-core/2.14.1, Apache-2.0 AND MIT, approved, #4303
 maven/mavencentral/com.fasterxml.jackson.core/jackson-core/2.15.1, MIT AND Apache-2.0, approved, #7932
 maven/mavencentral/com.fasterxml.jackson.core/jackson-core/2.17.0, , approved, #13665
+maven/mavencentral/com.fasterxml.jackson.core/jackson-core/2.17.1, , approved, #13665
 maven/mavencentral/com.fasterxml.jackson.core/jackson-databind/2.11.0, Apache-2.0, approved, CQ23093
 maven/mavencentral/com.fasterxml.jackson.core/jackson-databind/2.14.0, Apache-2.0, approved, #4105
 maven/mavencentral/com.fasterxml.jackson.core/jackson-databind/2.14.1, Apache-2.0, approved, #4105
 maven/mavencentral/com.fasterxml.jackson.core/jackson-databind/2.15.1, Apache-2.0, approved, #7934
 maven/mavencentral/com.fasterxml.jackson.core/jackson-databind/2.17.0, Apache-2.0, approved, #13671
+maven/mavencentral/com.fasterxml.jackson.core/jackson-databind/2.17.1, Apache-2.0, approved, #13671
 maven/mavencentral/com.fasterxml.jackson.dataformat/jackson-dataformat-yaml/2.14.0, Apache-2.0, approved, #5933
 maven/mavencentral/com.fasterxml.jackson.dataformat/jackson-dataformat-yaml/2.15.1, Apache-2.0, approved, #8802
-maven/mavencentral/com.fasterxml.jackson.dataformat/jackson-dataformat-yaml/2.17.0, Apache-2.0, approved, #13669
+maven/mavencentral/com.fasterxml.jackson.dataformat/jackson-dataformat-yaml/2.17.1, Apache-2.0, approved, #13669
 maven/mavencentral/com.fasterxml.jackson.datatype/jackson-datatype-jakarta-jsonp/2.17.0, Apache-2.0, approved, #14161
+maven/mavencentral/com.fasterxml.jackson.datatype/jackson-datatype-jakarta-jsonp/2.17.1, Apache-2.0, approved, #14161
 maven/mavencentral/com.fasterxml.jackson.datatype/jackson-datatype-jsr310/2.14.0, Apache-2.0, approved, #4699
 maven/mavencentral/com.fasterxml.jackson.datatype/jackson-datatype-jsr310/2.15.1, Apache-2.0, approved, #7930
 maven/mavencentral/com.fasterxml.jackson.datatype/jackson-datatype-jsr310/2.17.0, Apache-2.0, approved, #14160
-maven/mavencentral/com.fasterxml.jackson.jakarta.rs/jackson-jakarta-rs-base/2.17.0, Apache-2.0, approved, #14194
+maven/mavencentral/com.fasterxml.jackson.datatype/jackson-datatype-jsr310/2.17.1, Apache-2.0, approved, #14160
+maven/mavencentral/com.fasterxml.jackson.jakarta.rs/jackson-jakarta-rs-base/2.17.1, Apache-2.0, approved, #14194
 maven/mavencentral/com.fasterxml.jackson.jakarta.rs/jackson-jakarta-rs-json-provider/2.15.1, Apache-2.0, approved, #9236
-maven/mavencentral/com.fasterxml.jackson.jakarta.rs/jackson-jakarta-rs-json-provider/2.17.0, Apache-2.0, approved, #14195
+maven/mavencentral/com.fasterxml.jackson.jakarta.rs/jackson-jakarta-rs-json-provider/2.17.1, Apache-2.0, approved, #14195
 maven/mavencentral/com.fasterxml.jackson.module/jackson-module-jakarta-xmlbind-annotations/2.17.0, Apache-2.0, approved, #13668
+maven/mavencentral/com.fasterxml.jackson.module/jackson-module-jakarta-xmlbind-annotations/2.17.1, Apache-2.0, approved, #13668
 maven/mavencentral/com.fasterxml.jackson/jackson-bom/2.15.1, Apache-2.0, approved, #7929
 maven/mavencentral/com.fasterxml.jackson/jackson-bom/2.17.0, Apache-2.0, approved, #14162
+maven/mavencentral/com.fasterxml.jackson/jackson-bom/2.17.1, Apache-2.0, approved, #14162
 maven/mavencentral/com.fasterxml.uuid/java-uuid-generator/4.1.0, Apache-2.0, approved, clearlydefined
 maven/mavencentral/com.github.cliftonlabs/json-simple/3.0.2, Apache-2.0, approved, clearlydefined
 maven/mavencentral/com.github.docker-java/docker-java-api/3.3.6, Apache-2.0, approved, #10346
@@ -78,7 +85,7 @@
 maven/mavencentral/com.networknt/json-schema-validator/1.0.76, Apache-2.0, approved, CQ22638
 maven/mavencentral/com.nimbusds/nimbus-jose-jwt/9.28, Apache-2.0, approved, clearlydefined
 maven/mavencentral/com.nimbusds/nimbus-jose-jwt/9.37.3, Apache-2.0, approved, #11701
-maven/mavencentral/com.puppycrawl.tools/checkstyle/10.15.0, LGPL-2.1-or-later, restricted, clearlydefined
+maven/mavencentral/com.puppycrawl.tools/checkstyle/10.16.0, , restricted, clearlydefined
 maven/mavencentral/com.samskivert/jmustache/1.15, BSD-2-Clause, approved, clearlydefined
 maven/mavencentral/com.squareup.okhttp3/okhttp-dnsoverhttps/4.12.0, Apache-2.0, approved, #11159
 maven/mavencentral/com.squareup.okhttp3/okhttp/4.12.0, Apache-2.0, approved, #11156

core/common/boot/src/main/java/org/eclipse/edc/boot/config/ConfigurationLoader.java

@@ -0,0 +1,63 @@
+/*
+ *  Copyright (c) 2024 Bayerische Motoren Werke Aktiengesellschaft (BMW AG)
+ *
+ *  This program and the accompanying materials are made available under the
+ *  terms of the Apache License, Version 2.0 which is available at
+ *  https://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  SPDX-License-Identifier: Apache-2.0
+ *
+ *  Contributors:
+ *       Bayerische Motoren Werke Aktiengesellschaft (BMW AG) - initial API and implementation
+ *
+ */
+
+package org.eclipse.edc.boot.config;
+
+import org.eclipse.edc.boot.system.ServiceLocator;
+import org.eclipse.edc.spi.monitor.Monitor;
+import org.eclipse.edc.spi.system.ConfigurationExtension;
+import org.eclipse.edc.spi.system.configuration.Config;
+import org.eclipse.edc.spi.system.configuration.ConfigFactory;
+
+import java.util.Objects;
+
+/**
+ * Load configuration from configuration extensions, environment variables and system properties.
+ */
+public class ConfigurationLoader {
+    private final ServiceLocator serviceLocator;
+    private final EnvironmentVariables environmentVariables;
+    private final SystemProperties systemProperties;
+
+    public ConfigurationLoader(ServiceLocator serviceLocator, EnvironmentVariables environmentVariables, SystemProperties systemProperties) {
+        this.serviceLocator = serviceLocator;
+        this.environmentVariables = environmentVariables;
+        this.systemProperties = systemProperties;
+    }
+
+    /**
+     * Load configuration.
+     * Please note that Environment variables keys will be converted from the ENVIRONMENT_NOTATION to the dot.notation.
+     *
+     * @param monitor the monitor.
+     * @return the Config instance.
+     */
+    public Config loadConfiguration(Monitor monitor) {
+        var config = serviceLocator.loadImplementors(ConfigurationExtension.class, false)
+                .stream().peek(extension -> {
+                    extension.initialize(monitor);
+                    monitor.info("Initialized " + extension.name());
+                })
+                .map(ConfigurationExtension::getConfig)
+                .filter(Objects::nonNull)
+                .reduce(Config::merge)
+                .orElse(ConfigFactory.empty());
+
+        var environmentConfig = ConfigFactory.fromEnvironment(environmentVariables.get());
+        var systemPropertyConfig = ConfigFactory.fromProperties(systemProperties.get());
+
+        return config.merge(environmentConfig).merge(systemPropertyConfig);
+    }
+
+}

core/common/boot/src/main/java/org/eclipse/edc/boot/config/EnvironmentVariables.java

@@ -0,0 +1,35 @@
+/*
+ *  Copyright (c) 2024 Bayerische Motoren Werke Aktiengesellschaft (BMW AG)
+ *
+ *  This program and the accompanying materials are made available under the
+ *  terms of the Apache License, Version 2.0 which is available at
+ *  https://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  SPDX-License-Identifier: Apache-2.0
+ *
+ *  Contributors:
+ *       Bayerische Motoren Werke Aktiengesellschaft (BMW AG) - initial API and implementation
+ *
+ */
+
+package org.eclipse.edc.boot.config;
+
+import java.util.Map;
+import java.util.function.Supplier;
+
+
+/**
+ * Wrapping interface that provides Environment Variables
+ */
+public interface EnvironmentVariables extends Supplier<Map<String, String>> {
+
+    /**
+     * Default implementation.
+     *
+     * @return the EnvironmentVariables default implementation.
+     */
+    static EnvironmentVariables ofDefault() {
+        return System::getenv;
+    }
+
+}

core/common/boot/src/main/java/org/eclipse/edc/boot/config/SystemProperties.java

@@ -0,0 +1,33 @@
+/*
+ *  Copyright (c) 2024 Bayerische Motoren Werke Aktiengesellschaft (BMW AG)
+ *
+ *  This program and the accompanying materials are made available under the
+ *  terms of the Apache License, Version 2.0 which is available at
+ *  https://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  SPDX-License-Identifier: Apache-2.0
+ *
+ *  Contributors:
+ *       Bayerische Motoren Werke Aktiengesellschaft (BMW AG) - initial API and implementation
+ *
+ */
+
+package org.eclipse.edc.boot.config;
+
+import java.util.Properties;
+import java.util.function.Supplier;
+
+/**
+ * Wrapping interface that provides System Properties
+ */
+public interface SystemProperties extends Supplier<Properties> {
+
+    /**
+     * Default implementation.
+     *
+     * @return the SystemProperties default implementation.
+     */
+    static SystemProperties ofDefault() {
+        return System::getProperties;
+    }
+}

core/common/boot/src/main/java/org/eclipse/edc/boot/system/DefaultServiceExtensionContext.java

@@ -18,15 +18,11 @@
 import org.eclipse.edc.boot.BootServicesExtension;
 import org.eclipse.edc.spi.EdcException;
 import org.eclipse.edc.spi.monitor.Monitor;
-import org.eclipse.edc.spi.system.ConfigurationExtension;
 import org.eclipse.edc.spi.system.ServiceExtensionContext;
 import org.eclipse.edc.spi.system.configuration.Config;
-import org.eclipse.edc.spi.system.configuration.ConfigFactory;
 
 import java.util.HashMap;
-import java.util.List;
 import java.util.Map;
-import java.util.Objects;
 import java.util.UUID;
 
 import static org.eclipse.edc.boot.BootServicesExtension.RUNTIME_ID;
@@ -41,14 +37,13 @@ public class DefaultServiceExtensionContext implements ServiceExtensionContext {
     private static final String EDC_CONNECTOR_NAME = "edc.connector.name";
 
     private final Map<Class<?>, Object> services = new HashMap<>();
-    private final List<ConfigurationExtension> configurationExtensions;
+    private final Config config;
     private boolean isReadOnly = false;
     private String participantId;
     private String runtimeId;
-    private Config config;
 
-    public DefaultServiceExtensionContext(Monitor monitor, List<ConfigurationExtension> configurationExtensions) {
-        this.configurationExtensions = configurationExtensions;
+    public DefaultServiceExtensionContext(Monitor monitor, Config config) {
+        this.config = config;
         // register as service
         registerService(Monitor.class, monitor);
     }
@@ -108,11 +103,6 @@ public <T> void registerService(Class<T> type, T service) {
 
     @Override
     public void initialize() {
-        configurationExtensions.forEach(ext -> {
-            ext.initialize(getMonitor());
-            getMonitor().info("Initialized " + ext.name());
-        });
-        config = loadConfig();
         participantId = getSetting(BootServicesExtension.PARTICIPANT_ID, ANONYMOUS_PARTICIPANT);
         if (ANONYMOUS_PARTICIPANT.equals(participantId)) {
             getMonitor().warning("The runtime is configured as an anonymous participant. DO NOT DO THIS IN PRODUCTION.");
@@ -136,21 +126,4 @@ public void initialize() {
 
     }
 
-    // this method exists so that getting env vars can be mocked during testing
-    protected Map<String, String> getEnvironmentVariables() {
-        return System.getenv();
-    }
-
-    private Config loadConfig() {
-        var config = configurationExtensions.stream()
-                .map(ConfigurationExtension::getConfig)
-                .filter(Objects::nonNull)
-                .reduce(Config::merge)
-                .orElse(ConfigFactory.empty());
-
-        var environmentConfig = ConfigFactory.fromEnvironment(getEnvironmentVariables());
-        var systemPropertyConfig = ConfigFactory.fromProperties(System.getProperties());
-
-        return config.merge(environmentConfig).merge(systemPropertyConfig);
-    }
 }

core/common/boot/src/main/java/org/eclipse/edc/boot/system/runtime/BaseRuntime.java

@@ -16,17 +16,20 @@
 package org.eclipse.edc.boot.system.runtime;
 
 
+import org.eclipse.edc.boot.config.ConfigurationLoader;
+import org.eclipse.edc.boot.config.EnvironmentVariables;
+import org.eclipse.edc.boot.config.SystemProperties;
 import org.eclipse.edc.boot.system.DefaultServiceExtensionContext;
 import org.eclipse.edc.boot.system.ExtensionLoader;
 import org.eclipse.edc.boot.system.ServiceLocator;
 import org.eclipse.edc.boot.system.ServiceLocatorImpl;
 import org.eclipse.edc.boot.system.injection.InjectionContainer;
 import org.eclipse.edc.spi.EdcException;
 import org.eclipse.edc.spi.monitor.Monitor;
-import org.eclipse.edc.spi.system.ConfigurationExtension;
 import org.eclipse.edc.spi.system.MonitorExtension;
 import org.eclipse.edc.spi.system.ServiceExtension;
 import org.eclipse.edc.spi.system.ServiceExtensionContext;
+import org.eclipse.edc.spi.system.configuration.Config;
 import org.eclipse.edc.spi.system.health.HealthCheckResult;
 import org.eclipse.edc.spi.system.health.HealthCheckService;
 import org.jetbrains.annotations.NotNull;
@@ -43,7 +46,7 @@
  * the connector. It goes through the following steps, all of which are overridable:
  * <ul>
  *     <li>{@link BaseRuntime#createMonitor()} : instantiates a new {@link Monitor}</li>
- *     <li>{@link BaseRuntime#createContext(Monitor)}: creates a new {@link DefaultServiceExtensionContext} and invokes its {@link DefaultServiceExtensionContext#initialize()} method</li>
+ *     <li>{@link BaseRuntime#createContext(Monitor, Config)}: creates a new {@link DefaultServiceExtensionContext} and invokes its {@link DefaultServiceExtensionContext#initialize()} method</li>
  *     <li>{@link BaseRuntime#createExtensions(ServiceExtensionContext)}: creates a list of {@code ServiceExtension} objects. By default, these are created through {@link ExtensionLoader#loadServiceExtensions(ServiceExtensionContext)}</li>
  *     <li>{@link BaseRuntime#bootExtensions(ServiceExtensionContext, List)}: initializes the service extensions by putting them through their lifecycle.
  *     By default this calls {@link ExtensionLoader#bootServiceExtensions(List, ServiceExtensionContext)} </li>
@@ -54,6 +57,7 @@ public class BaseRuntime {
 
     private static String[] programArgs = new String[0];
     private final ExtensionLoader extensionLoader;
+    private final ConfigurationLoader configurationLoader;
     private final List<ServiceExtension> serviceExtensions = new ArrayList<>();
     protected Monitor monitor;
 
@@ -63,6 +67,7 @@ public BaseRuntime() {
 
     protected BaseRuntime(ServiceLocator serviceLocator) {
         extensionLoader = new ExtensionLoader(serviceLocator);
+        configurationLoader = new ConfigurationLoader(serviceLocator, EnvironmentVariables.ofDefault(), SystemProperties.ofDefault());
     }
 
     public static void main(String[] args) {
@@ -106,20 +111,10 @@ protected Monitor getMonitor() {
     }
 
     @NotNull
-    protected ServiceExtensionContext createServiceExtensionContext() {
-        var context = createContext(monitor);
-        initializeContext(context);
-        return context;
-    }
-
-    /**
-     * Initializes the context. If {@link BaseRuntime#createContext(Monitor)} is overridden and the (custom) context
-     * needs to be initialized, this method should be overridden as well.
-     *
-     * @param context The context.
-     */
-    protected void initializeContext(ServiceExtensionContext context) {
+    protected ServiceExtensionContext createServiceExtensionContext(Config config) {
+        var context = createContext(monitor, config);
         context.initialize();
+        return context;
     }
 
     /**
@@ -155,15 +150,12 @@ protected List<InjectionContainer<ServiceExtension>> createExtensions(ServiceExt
      * this would likely need to be overridden.
      *
      * @param monitor a Monitor
+     * @param config the cofiguratiohn
      * @return a {@code ServiceExtensionContext}
      */
     @NotNull
-    protected ServiceExtensionContext createContext(Monitor monitor) {
-        return new DefaultServiceExtensionContext(monitor, loadConfigurationExtensions());
-    }
-
-    protected List<ConfigurationExtension> loadConfigurationExtensions() {
-        return extensionLoader.loadExtensions(ConfigurationExtension.class, false);
+    protected ServiceExtensionContext createContext(Monitor monitor, Config config) {
+        return new DefaultServiceExtensionContext(monitor, config);
     }
 
     /**
@@ -179,7 +171,8 @@ protected Monitor createMonitor() {
 
     private void boot(boolean addShutdownHook) {
         monitor = createMonitor();
-        var context = createServiceExtensionContext();
+        var config = configurationLoader.loadConfiguration(monitor);
+        var context = createServiceExtensionContext(config);
 
         try {
             var newExtensions = createExtensions(context);