Set root logger level for CLIs (elastic#123742)

All CLIs in elasticsearch support command line flags for controlling the
output level. When --silent is used, the expectation is that normal
logging is omitted. Yet the log4j logger is still configured to output
error level logs. This commit sets the appropriate log level for log4j
depending on the Terminal log level.

Author: rjernst

libs/cli/build.gradle

@@ -12,6 +12,7 @@ apply plugin: 'elasticsearch.publish'
 dependencies {
   api 'net.sf.jopt-simple:jopt-simple:5.0.2'
   api project(':libs:core')
+  api project(':libs:logging')
 
   testImplementation(project(":test:framework")) {
     exclude group: 'org.elasticsearch', module: 'cli'

libs/cli/src/main/java/module-info.java

@@ -11,6 +11,8 @@
 module org.elasticsearch.cli {
     requires jopt.simple;
     requires org.elasticsearch.base;
+    requires java.logging;
+    requires org.elasticsearch.logging;
 
     exports org.elasticsearch.cli;
 }

libs/cli/src/main/java/org/elasticsearch/cli/Command.java

@@ -15,6 +15,8 @@
 import joptsimple.OptionSpec;
 
 import org.elasticsearch.core.SuppressForbidden;
+import org.elasticsearch.logging.Level;
+import org.elasticsearch.logging.internal.spi.LoggerFactory;
 
 import java.io.Closeable;
 import java.io.IOException;
@@ -84,12 +86,16 @@ protected void mainWithoutErrorHandling(String[] args, Terminal terminal, Proces
             return;
         }
 
+        LoggerFactory loggerFactory = LoggerFactory.provider();
         if (options.has(silentOption)) {
             terminal.setVerbosity(Terminal.Verbosity.SILENT);
+            loggerFactory.setRootLevel(Level.OFF);
         } else if (options.has(verboseOption)) {
             terminal.setVerbosity(Terminal.Verbosity.VERBOSE);
+            loggerFactory.setRootLevel(Level.DEBUG);
         } else {
             terminal.setVerbosity(Terminal.Verbosity.NORMAL);
+            loggerFactory.setRootLevel(Level.INFO);
         }
 
         execute(terminal, options, processInfo);

libs/logging/src/main/java/module-info.java

@@ -9,5 +9,5 @@
 
 module org.elasticsearch.logging {
     exports org.elasticsearch.logging;
-    exports org.elasticsearch.logging.internal.spi to org.elasticsearch.server;
+    exports org.elasticsearch.logging.internal.spi to org.elasticsearch.server, org.elasticsearch.cli;
 }

libs/logging/src/main/java/org/elasticsearch/logging/internal/spi/LoggerFactory.java

@@ -9,6 +9,7 @@
 
 package org.elasticsearch.logging.internal.spi;
 
+import org.elasticsearch.logging.Level;
 import org.elasticsearch.logging.Logger;
 
 /**
@@ -26,6 +27,10 @@ public static LoggerFactory provider() {
 
     public abstract Logger getLogger(Class<?> clazz);
 
+    public abstract void setRootLevel(Level level);
+
+    public abstract Level getRootLevel();
+
     public static void setInstance(LoggerFactory INSTANCE) {
         LoggerFactory.INSTANCE = INSTANCE;
     }

server/src/main/java/org/elasticsearch/common/logging/internal/LevelUtil.java

@@ -9,20 +9,51 @@
 
 package org.elasticsearch.common.logging.internal;
 
+import static org.apache.logging.log4j.Level.ALL;
+import static org.apache.logging.log4j.Level.DEBUG;
+import static org.apache.logging.log4j.Level.ERROR;
+import static org.apache.logging.log4j.Level.FATAL;
+import static org.apache.logging.log4j.Level.INFO;
+import static org.apache.logging.log4j.Level.OFF;
+import static org.apache.logging.log4j.Level.TRACE;
+import static org.apache.logging.log4j.Level.WARN;
+
 public final class LevelUtil {
 
     private LevelUtil() {}
 
     public static org.apache.logging.log4j.Level log4jLevel(final org.elasticsearch.logging.Level level) {
         return switch (level) {
-            case OFF -> org.apache.logging.log4j.Level.OFF;
-            case FATAL -> org.apache.logging.log4j.Level.FATAL;
+            case OFF -> OFF;
+            case FATAL -> FATAL;
             case ERROR -> org.apache.logging.log4j.Level.ERROR;
-            case WARN -> org.apache.logging.log4j.Level.WARN;
+            case WARN -> WARN;
             case INFO -> org.apache.logging.log4j.Level.INFO;
             case DEBUG -> org.apache.logging.log4j.Level.DEBUG;
-            case TRACE -> org.apache.logging.log4j.Level.TRACE;
+            case TRACE -> TRACE;
             case ALL -> org.apache.logging.log4j.Level.ALL;
         };
     }
+
+    public static org.elasticsearch.logging.Level elasticsearchLevel(final org.apache.logging.log4j.Level log4jLevel) {
+        // we can't use a switch because log4j levels are not an enum
+        if (log4jLevel == OFF) {
+            return org.elasticsearch.logging.Level.OFF;
+        } else if (log4jLevel == FATAL) {
+            return org.elasticsearch.logging.Level.FATAL;
+        } else if (log4jLevel == ERROR) {
+            return org.elasticsearch.logging.Level.ERROR;
+        } else if (log4jLevel == WARN) {
+            return org.elasticsearch.logging.Level.WARN;
+        } else if (log4jLevel == INFO) {
+            return org.elasticsearch.logging.Level.INFO;
+        } else if (log4jLevel == DEBUG) {
+            return org.elasticsearch.logging.Level.DEBUG;
+        } else if (log4jLevel == TRACE) {
+            return org.elasticsearch.logging.Level.TRACE;
+        } else if (log4jLevel == ALL) {
+            return org.elasticsearch.logging.Level.ALL;
+        }
+        throw new AssertionError("unknown log4j level [" + log4jLevel + "]");
+    }
 }

server/src/main/java/org/elasticsearch/common/logging/internal/LoggerFactoryImpl.java

@@ -10,6 +10,8 @@
 package org.elasticsearch.common.logging.internal;
 
 import org.apache.logging.log4j.LogManager;
+import org.elasticsearch.common.logging.Loggers;
+import org.elasticsearch.logging.Level;
 import org.elasticsearch.logging.Logger;
 import org.elasticsearch.logging.internal.spi.LoggerFactory;
 
@@ -30,4 +32,15 @@ public Logger getLogger(Class<?> clazz) {
         // classloader a class comes from, we will use the root logging config.
         return getLogger(clazz.getName());
     }
+
+    @Override
+    public void setRootLevel(Level level) {
+        var log4jLevel = LevelUtil.log4jLevel(level);
+        Loggers.setLevel(LogManager.getRootLogger(), log4jLevel);
+    }
+
+    @Override
+    public Level getRootLevel() {
+        return LevelUtil.elasticsearchLevel(LogManager.getRootLogger().getLevel());
+    }
 }

test/framework/src/main/java/org/elasticsearch/test/ESTestCase.java

@@ -117,6 +117,7 @@
 import org.elasticsearch.indices.IndicesModule;
 import org.elasticsearch.indices.analysis.AnalysisModule;
 import org.elasticsearch.jdk.RuntimeVersionFeature;
+import org.elasticsearch.logging.internal.spi.LoggerFactory;
 import org.elasticsearch.plugins.AnalysisPlugin;
 import org.elasticsearch.plugins.Plugin;
 import org.elasticsearch.plugins.scanners.StablePluginsRegistry;
@@ -576,6 +577,23 @@ public void removeHeaderWarningAppender() {
         }
     }
 
+    private static org.elasticsearch.logging.Level capturedLogLevel = null;
+
+    // just capture the expected level once before the suite starts
+    @BeforeClass
+    public static void captureLoggingLevel() {
+        capturedLogLevel = LoggerFactory.provider().getRootLevel();
+    }
+
+    @AfterClass
+    public static void restoreLoggingLevel() {
+        if (capturedLogLevel != null) {
+            // log level might not have been captured if suite was skipped
+            LoggerFactory.provider().setRootLevel(capturedLogLevel);
+            capturedLogLevel = null;
+        }
+    }
+
     @Before
     public final void before() {
         LeakTracker.setContextHint(getTestName());

x-pack/plugin/security/src/main/java/module-info.java

@@ -49,6 +49,7 @@
     requires oauth2.oidc.sdk;
     requires org.slf4j;
     requires unboundid.ldapsdk;
+    requires org.elasticsearch.logging;
 
     exports org.elasticsearch.xpack.security.action to org.elasticsearch.server;
     exports org.elasticsearch.xpack.security.action.apikey to org.elasticsearch.server;