Merge pull request #123 from avaje/feature/plugin

Add ConfigurationPlugin and avaje-dynamic-logback

Author: rbygrave

avaje-config/src/main/java/io/avaje/config/ConfigurationPlugin.java

@@ -0,0 +1,17 @@
+package io.avaje.config;
+
+import java.util.function.Consumer;
+
+/**
+ * Plugin that is initiated after the configuration has been loaded.
+ */
+public interface ConfigurationPlugin {
+
+  /**
+   * Apply the plugin. Typically, a plugin might read configuration and do something
+   * and listen for configuration changes via {@link Configuration#onChange(Consumer, String...)}.
+   *
+   * @param configuration The configuration that has been loaded including all {@link ConfigurationSource}.
+   */
+  void apply(Configuration configuration);
+}

avaje-config/src/main/java/io/avaje/config/CoreComponents.java

@@ -9,19 +9,22 @@ final class CoreComponents {
   private final ConfigurationLog log;
   private final Parsers parsers;
   private final List<ConfigurationSource> sources;
+  private final List<ConfigurationPlugin> plugins;
 
-  CoreComponents(ModificationEventRunner runner, ConfigurationLog log, Parsers parsers, List<ConfigurationSource> sources) {
+  CoreComponents(ModificationEventRunner runner, ConfigurationLog log, Parsers parsers, List<ConfigurationSource> sources, List<ConfigurationPlugin> plugins) {
     this.runner = runner;
     this.log = log;
     this.parsers = parsers;
     this.sources = sources;
+    this.plugins = plugins;
   }
 
   CoreComponents() {
     this.runner = new CoreConfiguration.ForegroundEventRunner();
     this.log = new DefaultConfigurationLog();
     this.parsers = new Parsers();
     this.sources = Collections.emptyList();
+    this.plugins = Collections.emptyList();
   }
 
   Parsers parsers() {
@@ -39,4 +42,8 @@ ModificationEventRunner runner() {
   List<ConfigurationSource> sources() {
     return sources;
   }
+
+  List<ConfigurationPlugin> plugins() {
+    return plugins;
+  }
 }

avaje-config/src/main/java/io/avaje/config/CoreConfiguration.java

@@ -37,6 +37,7 @@ final class CoreConfiguration implements Configuration {
   private final CoreSetValue setValue;
   private final ModificationEventRunner eventRunner;
   private final List<ConfigurationSource> sources;
+  private final List<ConfigurationPlugin> plugins;
 
   private boolean loadedSystemProperties;
   private FileWatch watcher;
@@ -48,6 +49,7 @@ final class CoreConfiguration implements Configuration {
     this.eventRunner = components.runner();
     this.log = components.log();
     this.sources = components.sources();
+    this.plugins = components.plugins();
     this.properties = new ModifyAwareProperties(entries);
     this.listValue = new CoreListValue(this);
     this.setValue = new CoreSetValue(this);
@@ -59,6 +61,7 @@ final class CoreConfiguration implements Configuration {
     this.eventRunner = parent.eventRunner;
     this.log = parent.log;
     this.sources = parent.sources;
+    this.plugins = parent.plugins;
     this.properties = new ModifyAwareProperties(entries);
     this.listValue = new CoreListValue(this);
     this.setValue = new CoreSetValue(this);
@@ -89,11 +92,18 @@ CoreConfiguration postLoad(@Nullable InitialLoader loader) {
     initSystemProperties();
     if (loader != null) {
       logMessage(loader);
+      applyPlugins();
     }
     log.postInitialisation();
     return this;
   }
 
+  private void applyPlugins() {
+    for (ConfigurationPlugin plugin : plugins) {
+      plugin.apply(this);
+    }
+  }
+
   ConfigurationLog log() {
     return log;
   }

avaje-config/src/main/java/io/avaje/config/CoreConfigurationBuilder.java

@@ -77,8 +77,11 @@ public Configuration build() {
     final var sources = ServiceLoader.load(ConfigurationSource.class).stream()
       .map(ServiceLoader.Provider::get)
       .collect(Collectors.toList());
+    final var plugins = ServiceLoader.load(ConfigurationPlugin.class).stream()
+      .map(ServiceLoader.Provider::get)
+      .collect(Collectors.toList());
 
-    var components = new CoreComponents(runner, log, parsers, sources);
+    var components = new CoreComponents(runner, log, parsers, sources, plugins);
     if (includeResourceLoading) {
       log.preInitialisation();
       initialLoader = new InitialLoader(components, initResourceLoader());

avaje-config/src/main/java/module-info.java

@@ -8,6 +8,7 @@
 
   uses io.avaje.config.ConfigParser;
   uses io.avaje.config.ConfigurationLog;
+  uses io.avaje.config.ConfigurationPlugin;
   uses io.avaje.config.ModificationEventRunner;
   uses io.avaje.config.ConfigurationSource;
   uses io.avaje.config.ResourceLoader;

avaje-dynamic-logback/pom.xml

@@ -0,0 +1,38 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+  <modelVersion>4.0.0</modelVersion>
+  <parent>
+    <groupId>org.avaje</groupId>
+    <artifactId>java11-oss</artifactId>
+    <version>4.0</version>
+    <relativePath/>
+  </parent>
+
+  <groupId>io.avaje</groupId>
+  <artifactId>avaje-dynamic-logback</artifactId>
+  <version>0.1</version>
+
+  <properties>
+    <surefire.useModulePath>false</surefire.useModulePath>
+  </properties>
+
+  <dependencies>
+
+    <dependency>
+      <groupId>io.avaje</groupId>
+      <artifactId>avaje-config</artifactId>
+      <version>3.12-RC1</version>
+    </dependency>
+
+    <dependency>
+      <groupId>ch.qos.logback</groupId>
+      <artifactId>logback-classic</artifactId>
+      <version>1.5.0</version>
+      <scope>provided</scope>
+    </dependency>
+
+  </dependencies>
+
+</project>

avaje-dynamic-logback/src/main/java/io/avaje/config/dynamiclogback/LogbackPlugin.java

@@ -0,0 +1,55 @@
+package io.avaje.config.dynamiclogback;
+
+import ch.qos.logback.classic.Level;
+import ch.qos.logback.classic.Logger;
+import ch.qos.logback.classic.LoggerContext;
+import io.avaje.applog.AppLog;
+import io.avaje.config.Configuration;
+import io.avaje.config.ConfigurationPlugin;
+import io.avaje.config.ModificationEvent;
+import org.slf4j.LoggerFactory;
+
+import static java.lang.System.Logger.Level.DEBUG;
+
+/**
+ * Plugin to dynamically adjust the log levels via configuration changes.
+ */
+public final class LogbackPlugin implements ConfigurationPlugin {
+
+  private static final System.Logger log = AppLog.getLogger(LogbackPlugin.class);
+
+  @Override
+  public void apply(Configuration configuration) {
+    final var loggerContext = loggerContext();
+    final var config = configuration.forPath("log.level");
+    for (String key : config.keys()) {
+      String rawLevel = configuration.get(key);
+      setLogLevel(key, loggerContext, rawLevel);
+    }
+    configuration.onChange(this::onChangeAny);
+  }
+
+  private static void setLogLevel(String key, LoggerContext loggerContext, String rawLevel) {
+    String logKey = key.substring(10);
+    Logger logger = loggerContext.getLogger(logKey);
+    if (logger != null) {
+      log.log(DEBUG, "logger change for {0} to {1}", logKey, rawLevel);
+      logger.setLevel(Level.toLevel(rawLevel));
+    }
+  }
+
+  private void onChangeAny(ModificationEvent modificationEvent) {
+    final var loggerContext = loggerContext();
+    final var config = modificationEvent.configuration();
+    modificationEvent.modifiedKeys().stream()
+      .filter(key -> key.startsWith("log.level."))
+      .forEach(key -> {
+        String rawLevel = config.get(key);
+        setLogLevel(key, loggerContext, rawLevel);
+      });
+  }
+
+  private LoggerContext loggerContext() {
+    return (LoggerContext) LoggerFactory.getILoggerFactory();
+  }
+}

avaje-dynamic-logback/src/main/java/module-info.java

@@ -0,0 +1,15 @@
+import io.avaje.config.ConfigurationPlugin;
+import io.avaje.config.dynamiclogback.LogbackPlugin;
+
+module io.avaje.config.dynamic.logback {
+
+  requires io.avaje.config;
+  requires transitive io.avaje.lang;
+  requires transitive io.avaje.applog;
+
+  requires static org.slf4j;
+  requires static ch.qos.logback.core;
+  requires static ch.qos.logback.classic;
+
+  provides ConfigurationPlugin with LogbackPlugin;
+}

avaje-dynamic-logback/src/main/resources/META-INF/services/io.avaje.config.ConfigurationPlugin

@@ -0,0 +1 @@
+io.avaje.config.dynamiclogback.LogbackPlugin

pom.xml

@@ -16,6 +16,7 @@
   <modules>
     <module>avaje-config</module>
     <module>avaje-aws-appconfig</module>
+    <module>avaje-dynamic-logback</module>
   </modules>
 
 </project>