Warn if unsupported logging configuration present

This commit adds a warning that an unsupported logging configuration is
present and points users to the new logging configuration file.

Relates #20309

core/src/main/java/org/elasticsearch/common/logging/LogConfigurator.java

@@ -30,6 +30,7 @@ import org.apache.logging.log4j.core.config.builder.impl.BuiltConfiguration;
 import org.apache.logging.log4j.core.config.composite.CompositeConfiguration;
 import org.apache.logging.log4j.core.config.properties.PropertiesConfiguration;
 import org.apache.logging.log4j.core.config.properties.PropertiesConfigurationFactory;
+import org.elasticsearch.Version;
 import org.elasticsearch.cluster.ClusterName;
 import org.elasticsearch.common.SuppressForbidden;
 import org.elasticsearch.common.settings.Settings;
@@ -43,6 +44,7 @@ import java.nio.file.Path;
 import java.nio.file.SimpleFileVisitor;
 import java.nio.file.attribute.BasicFileAttributes;
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.EnumSet;
 import java.util.List;
 import java.util.Map;
@@ -63,9 +65,9 @@ public class LogConfigurator {
         final LoggerContext context = (LoggerContext) LogManager.getContext(false);
 
         if (resolveConfig) {
-            final Set<FileVisitOption> options = EnumSet.of(FileVisitOption.FOLLOW_LINKS);
             final List<AbstractConfiguration> configurations = new ArrayList<>();
             final PropertiesConfigurationFactory factory = new PropertiesConfigurationFactory();
+            final Set<FileVisitOption> options = EnumSet.of(FileVisitOption.FOLLOW_LINKS);
             Files.walkFileTree(environment.configFile(), options, Integer.MAX_VALUE, new SimpleFileVisitor<Path>() {
                 @Override
                 public FileVisitResult visitFile(Path file, BasicFileAttributes attrs) throws IOException {
@@ -87,10 +89,36 @@ public class LogConfigurator {
             final Level level = ESLoggerFactory.LOG_LEVEL_SETTING.getConcreteSetting(key).get(settings);
             Loggers.setLevel(Loggers.getLogger(key.substring("logger.".length())), level);
         }
+
+        warnIfOldConfigurationFilePresent(environment);
+    }
+
+    private static void warnIfOldConfigurationFilePresent(final Environment environment) throws IOException {
+        // TODO: the warning for unsupported logging configurations can be removed in 6.0.0
+        assert Version.CURRENT.major < 6;
+        final List<String> suffixes = Arrays.asList(".yml", ".yaml", ".json", ".properties");
+        final Set<FileVisitOption> options = EnumSet.of(FileVisitOption.FOLLOW_LINKS);
+        Files.walkFileTree(environment.configFile(), options, Integer.MAX_VALUE, new SimpleFileVisitor<Path>() {
+            @Override
+            public FileVisitResult visitFile(Path file, BasicFileAttributes attrs) throws IOException {
+                final String fileName = file.getFileName().toString();
+                if (fileName.startsWith("logging")) {
+                    for (final String suffix : suffixes) {
+                        if (fileName.endsWith(suffix)) {
+                            Loggers.getLogger(LogConfigurator.class).warn(
+                                "ignoring unsupported logging configuration file [{}], logging is configured via [{}]",
+                                file.toString(),
+                                file.getParent().resolve("log4j2.properties"));
+                        }
+                    }
+                }
+                return FileVisitResult.CONTINUE;
+            }
+        });
     }
 
     @SuppressForbidden(reason = "sets system property for logging configuration")
-    private static void setLogConfigurationSystemProperty(Environment environment, Settings settings) {
+    private static void setLogConfigurationSystemProperty(final Environment environment, final Settings settings) {
         System.setProperty("es.logs", environment.logsFile().resolve(ClusterName.CLUSTER_NAME_SETTING.get(settings).value()).toString());
     }
 

qa/evil-tests/src/test/java/org/elasticsearch/common/logging/EvilLoggerTests.java

@@ -21,15 +21,16 @@ package org.elasticsearch.common.logging;
 
 import org.apache.logging.log4j.Level;
 import org.apache.logging.log4j.Logger;
+import org.elasticsearch.Version;
 import org.elasticsearch.common.io.PathUtils;
 import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.env.Environment;
 import org.elasticsearch.test.ESTestCase;
+import org.elasticsearch.test.hamcrest.RegexMatcher;
 
 import java.io.IOException;
 import java.nio.file.Files;
 import java.nio.file.Path;
-import java.nio.file.Paths;
 import java.util.List;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
@@ -66,21 +67,22 @@ public class EvilLoggerTests extends ESTestCase {
         testLogger.trace("This is a trace message");
         final String path = System.getProperty("es.logs") + ".log";
         final List<String> events = Files.readAllLines(PathUtils.get(path));
-        assertThat(events.size(), equalTo(5));
+        assertThat(events.size(), equalTo(6)); // the five messages me log plus a warning for unsupported configuration files
         final String location = "org.elasticsearch.common.logging.EvilLoggerTests.testLocationInfoTest";
-        assertLogLine(events.get(0), Level.ERROR, location, "This is an error message");
-        assertLogLine(events.get(1), Level.WARN, location, "This is a warning message");
-        assertLogLine(events.get(2), Level.INFO, location, "This is an info message");
-        assertLogLine(events.get(3), Level.DEBUG, location, "This is a debug message");
-        assertLogLine(events.get(4), Level.TRACE, location, "This is a trace message");
+        // the first message is a warning for unsupported configuration files
+        assertLogLine(events.get(1), Level.ERROR, location, "This is an error message");
+        assertLogLine(events.get(2), Level.WARN, location, "This is a warning message");
+        assertLogLine(events.get(3), Level.INFO, location, "This is an info message");
+        assertLogLine(events.get(4), Level.DEBUG, location, "This is a debug message");
+        assertLogLine(events.get(5), Level.TRACE, location, "This is a trace message");
     }
 
     private void assertLogLine(final String logLine, final Level level, final String location, final String message) {
         final Matcher matcher = Pattern.compile("\\[(.*)\\]\\[(.*)\\(.*\\)\\] (.*)").matcher(logLine);
         assertTrue(logLine, matcher.matches());
         assertThat(matcher.group(1), equalTo(level.toString()));
-        assertThat(matcher.group(2), equalTo(location));
-        assertThat(matcher.group(3), equalTo(message));
+        assertThat(matcher.group(2), RegexMatcher.matches(location));
+        assertThat(matcher.group(3), RegexMatcher.matches(message));
     }
 
     public void testDeprecationLogger() throws IOException {
@@ -95,4 +97,17 @@ public class EvilLoggerTests extends ESTestCase {
             "This is a deprecation message");
     }
 
+    public void testUnsupportedLoggingConfigurationFiles() throws IOException {
+        // TODO: the warning for unsupported logging configurations can be removed in 6.0.0
+        assert Version.CURRENT.major < 6;
+        final String path = System.getProperty("es.logs") + ".log";
+        final List<String> events = Files.readAllLines(PathUtils.get(path));
+        assertThat(events.size(), equalTo(1));
+        assertLogLine(
+            events.get(0),
+            Level.WARN,
+            "org\\.elasticsearch\\.common\\.logging\\.LogConfigurator.*",
+            "ignoring unsupported logging configuration file \\[.*\\], logging is configured via \\[.*\\]");
+    }
+
 }

qa/evil-tests/src/test/resources/org/elasticsearch/common/logging/config/logging.yml

@@ -0,0 +1,2 @@
+logger.level: INFO
+rootLogger: ${logger.level}, terminal