Add option to provide URIs to monitor in addition to the config file

A change detected in either the config file itself or the provided additional URIs shall result in a reconfigure

Signed-off-by: MichaelMorris <[email protected]>

Author: MichaelMorrisEst

log4j-core-test/src/test/java/org/apache/logging/log4j/core/LoggerTest.java

@@ -544,6 +544,30 @@ void testReconfiguration(final LoggerContext context) throws Exception {
         assertNotSame(newConfig, oldConfig, "Reconfiguration failed");
     }
 
+    @Test
+    void testReconfigurationMonitorUris(final LoggerContext context) throws Exception {
+        final Configuration oldConfig = context.getConfiguration();
+        final int MONITOR_INTERVAL_SECONDS = 5;
+        final File file = new File("target/test-classes/org/apache/logging/log4j/core/net/ssl/keyStore.p12");
+        final long orig = file.lastModified();
+        final long newTime = orig + 10000;
+        assertTrue(file.setLastModified(newTime), "setLastModified should have succeeded.");
+        TimeUnit.SECONDS.sleep(MONITOR_INTERVAL_SECONDS + 1);
+        for (int i = 0; i < 17; ++i) {
+            logger.debug("Reconfigure");
+        }
+        Thread.sleep(100);
+        for (int i = 0; i < 20; i++) {
+            if (context.getConfiguration() != oldConfig) {
+                break;
+            }
+            Thread.sleep(50);
+        }
+        final Configuration newConfig = context.getConfiguration();
+        assertNotNull(newConfig, "No configuration");
+        assertNotSame(newConfig, oldConfig, "Reconfiguration failed");
+    }
+
     @Test
     void testSuppressedThrowable(final LoggerContext context) {
         final org.apache.logging.log4j.Logger testLogger = context.getLogger("org.apache.logging.log4j.nothrown");

log4j-core-test/src/test/java/org/apache/logging/log4j/core/PropertiesFileConfigTest.java

@@ -64,4 +64,25 @@ void testReconfiguration(final LoggerContext context) throws Exception {
         } while (newConfig == oldConfig && loopCount++ < 5);
         assertNotSame(newConfig, oldConfig, "Reconfiguration failed");
     }
+
+    @Test
+    void testReconfigurationMonitorUris(final LoggerContext context) throws Exception {
+        final Configuration oldConfig = context.getConfiguration();
+        final int MONITOR_INTERVAL_SECONDS = 5;
+        final File file = new File("target/test-classes/org/apache/logging/log4j/core/net/ssl/keyStore.p12");
+        final long orig = file.lastModified();
+        final long newTime = orig + 10000;
+        assertTrue(file.setLastModified(newTime), "setLastModified should have succeeded.");
+        TimeUnit.SECONDS.sleep(MONITOR_INTERVAL_SECONDS + 1);
+        for (int i = 0; i < 17; ++i) {
+            logger.info("Reconfigure");
+        }
+        int loopCount = 0;
+        Configuration newConfig;
+        do {
+            Thread.sleep(100);
+            newConfig = context.getConfiguration();
+        } while (newConfig == oldConfig && loopCount++ < 5);
+        assertNotSame(newConfig, oldConfig, "Reconfiguration failed");
+    }
 }

log4j-core-test/src/test/resources/log4j-test2.properties

@@ -18,6 +18,7 @@
 status = debug
 name = PropertiesConfigTest
 monitorInterval = 1
+monitorUris = target/test-classes/org/apache/logging/log4j/core/net/ssl/keyStore.p12
 
 property.filename = target/test-properties.log
 

log4j-core-test/src/test/resources/log4j-test2.xml

@@ -15,7 +15,7 @@
   ~ See the License for the specific language governing permissions and
   ~ limitations under the License.
   -->
-<Configuration status="OFF" name="XMLConfigTest" monitorInterval="1">
+<Configuration status="OFF" name="XMLConfigTest" monitorInterval="1" monitorUris="target/test-classes/org/apache/logging/log4j/core/net/ssl/keyStore.p12">
   <Appenders>
     <RollingFile name="HostFile" fileName="target/${hostName}.log" filePattern="target/${hostName}-%d{MM-dd-yyyy}-%i.log">
       <PatternLayout>

log4j-core/src/main/java/org/apache/logging/log4j/core/config/AbstractConfiguration.java

@@ -275,6 +275,14 @@ protected void initializeWatchers(
             final Reconfigurable reconfigurable,
             final ConfigurationSource configSource,
             final int monitorIntervalSeconds) {
+        initializeWatchers(reconfigurable, configSource, Collections.emptySet(), monitorIntervalSeconds);
+    }
+
+    protected void initializeWatchers(
+            final Reconfigurable reconfigurable,
+            final ConfigurationSource configSource,
+            final Collection<Source> auxiliarySources,
+            final int monitorIntervalSeconds) {
         if (configSource != null && (configSource.getFile() != null || configSource.getURL() != null)) {
             if (monitorIntervalSeconds > 0) {
                 watchManager.setIntervalSeconds(monitorIntervalSeconds);
@@ -284,7 +292,7 @@ protected void initializeWatchers(
                     final long lastModified = file.lastModified();
                     final ConfigurationFileWatcher watcher =
                             new ConfigurationFileWatcher(this, reconfigurable, listeners, lastModified);
-                    watchManager.watch(cfgSource, watcher);
+                    watchManager.watch(cfgSource, auxiliarySources, watcher);
                 } else if (configSource.getURL() != null) {
                     monitorSource(reconfigurable, configSource);
                 }

log4j-core/src/main/java/org/apache/logging/log4j/core/config/ConfigurationFileWatcher.java

@@ -17,7 +17,10 @@
 package org.apache.logging.log4j.core.config;
 
 import java.io.File;
+import java.util.Collection;
+import java.util.HashMap;
 import java.util.List;
+import java.util.Map;
 import org.apache.logging.log4j.core.util.AbstractWatcher;
 import org.apache.logging.log4j.core.util.FileWatcher;
 import org.apache.logging.log4j.core.util.Source;
@@ -30,6 +33,7 @@ public class ConfigurationFileWatcher extends AbstractWatcher implements FileWat
 
     private File file;
     private long lastModifiedMillis;
+    private Map<File, Long> auxiliaryFiles = new HashMap<>();
 
     public ConfigurationFileWatcher(
             final Configuration configuration,
@@ -42,12 +46,23 @@ public ConfigurationFileWatcher(
 
     @Override
     public long getLastModified() {
-        return file != null ? file.lastModified() : 0;
+        Long latestModifiedAuxFile = 0L;
+        for (final File auxFile : auxiliaryFiles.keySet()) {
+            if (auxFile.lastModified() > latestModifiedAuxFile) {
+                latestModifiedAuxFile = auxFile.lastModified();
+            }
+        }
+
+        return file != null
+                ? file.lastModified() > latestModifiedAuxFile ? file.lastModified() : latestModifiedAuxFile
+                : 0;
     }
 
     @Override
     public void fileModified(final File file) {
         lastModifiedMillis = file.lastModified();
+        auxiliaryFiles.entrySet().stream()
+                .forEach(auxFile -> auxFile.setValue(auxFile.getKey().lastModified()));
     }
 
     @Override
@@ -57,9 +72,25 @@ public void watching(final Source source) {
         super.watching(source);
     }
 
+    /**
+     * Called when the Watcher is registered.
+     * @param source the Source that is being watched.
+     * @param auxiliarySources auxiliary sources also being watched.
+     */
+    public void watching(final Source source, final Collection<Source> auxiliarySources) {
+        file = source.getFile();
+        lastModifiedMillis = file.lastModified();
+        auxiliarySources.forEach(auxSource -> {
+            auxiliaryFiles.put(auxSource.getFile(), auxSource.getFile().lastModified());
+        });
+        super.watching(source);
+    }
+
     @Override
     public boolean isModified() {
-        return lastModifiedMillis != file.lastModified();
+        return lastModifiedMillis != file.lastModified()
+                || auxiliaryFiles.entrySet().stream()
+                        .anyMatch(file -> file.getValue() != file.getKey().lastModified());
     }
 
     @Override

log4j-core/src/main/java/org/apache/logging/log4j/core/config/builder/api/ConfigurationBuilder.java

@@ -418,6 +418,15 @@ public interface ConfigurationBuilder<T extends Configuration> extends Builder<T
      */
     ConfigurationBuilder<T> setMonitorInterval(String intervalSeconds);
 
+    /**
+     * Set the URIs to be monitored in addition to the configuration file
+     * @param monitorUris the URIs to monitor
+     * @return this builder instance
+     */
+    default ConfigurationBuilder<T> setMonitorUris(final String monitorUris) {
+        return this;
+    }
+
     /**
      * Sets the list of packages to search for plugins.
      * @param packages The comma separated list of packages.

log4j-core/src/main/java/org/apache/logging/log4j/core/config/builder/api/package-info.java

@@ -20,7 +20,7 @@
  * @since 2.4
  */
 @Export
-@Version("2.20.1")
+@Version("2.21.0")
 package org.apache.logging.log4j.core.config.builder.api;
 
 import org.osgi.annotation.bundle.Export;

log4j-core/src/main/java/org/apache/logging/log4j/core/config/builder/impl/BuiltConfiguration.java

@@ -18,7 +18,11 @@
 
 import java.io.IOException;
 import java.io.InputStream;
+import java.net.URI;
+import java.net.URISyntaxException;
 import java.util.Arrays;
+import java.util.Collection;
+import java.util.HashSet;
 import java.util.List;
 import org.apache.logging.log4j.core.LoggerContext;
 import org.apache.logging.log4j.core.config.AbstractConfiguration;
@@ -30,6 +34,8 @@
 import org.apache.logging.log4j.core.config.plugins.util.PluginType;
 import org.apache.logging.log4j.core.config.status.StatusConfiguration;
 import org.apache.logging.log4j.core.util.Patterns;
+import org.apache.logging.log4j.core.util.Source;
+import org.apache.logging.log4j.util.Strings;
 
 /**
  * This is the general version of the Configuration created by the Builder. It may be extended to
@@ -148,9 +154,28 @@ public void setShutdownTimeoutMillis(final long shutdownTimeoutMillis) {
     }
 
     public void setMonitorInterval(final int intervalSeconds) {
+        initializeMonitoring(intervalSeconds, "");
+    }
+
+    public void initializeMonitoring(final int intervalSeconds, final String monitorUris) {
         if (this instanceof Reconfigurable && intervalSeconds > 0) {
-            initializeWatchers((Reconfigurable) this, getConfigurationSource(), intervalSeconds);
+            initializeWatchers(
+                    (Reconfigurable) this, getConfigurationSource(), getAuxiliarySources(monitorUris), intervalSeconds);
+        }
+    }
+
+    private Collection<Source> getAuxiliarySources(final String monitorUris) {
+        final Collection<Source> auxiliarySources = new HashSet<>();
+        if (Strings.isNotBlank(monitorUris)) {
+            for (final String uri : Arrays.asList(monitorUris.split(Patterns.COMMA_SEPARATOR))) {
+                try {
+                    auxiliarySources.add(new Source(new URI(uri)));
+                } catch (URISyntaxException e) {
+                    LOGGER.error("Error parsing monitorUris: " + monitorUris, e);
+                }
+            }
         }
+        return auxiliarySources;
     }
 
     @Override

log4j-core/src/main/java/org/apache/logging/log4j/core/config/builder/impl/DefaultConfigurationBuilder.java

@@ -61,6 +61,7 @@
 import org.apache.logging.log4j.core.config.builder.api.ScriptFileComponentBuilder;
 import org.apache.logging.log4j.core.util.Integers;
 import org.apache.logging.log4j.core.util.Throwables;
+import org.apache.logging.log4j.util.Strings;
 
 /**
  * @param <T> The BuiltConfiguration type.
@@ -80,6 +81,7 @@ public class DefaultConfigurationBuilder<T extends BuiltConfiguration> implement
     private final Class<T> clazz;
     private ConfigurationSource source;
     private int monitorInterval;
+    private String monitorUris;
     private Level level;
     private String destination;
     private String packages;
@@ -214,7 +216,7 @@ public T build(final boolean initialize) {
             if (advertiser != null) {
                 configuration.createAdvertiser(advertiser, source);
             }
-            configuration.setMonitorInterval(monitorInterval);
+            configuration.initializeMonitoring(monitorInterval, monitorUris);
         } catch (final Exception ex) {
             throw new IllegalArgumentException("Invalid Configuration class specified", ex);
         }
@@ -287,6 +289,9 @@ private void writeXmlConfiguration(final XMLStreamWriter xmlWriter) throws XMLSt
         if (monitorInterval > 0) {
             xmlWriter.writeAttribute("monitorInterval", String.valueOf(monitorInterval));
         }
+        if (Strings.isNotBlank(monitorUris)) {
+            xmlWriter.writeAttribute("monitorUris", monitorUris);
+        }
 
         writeXmlSection(xmlWriter, properties);
         writeXmlSection(xmlWriter, scripts);
@@ -565,6 +570,12 @@ public ConfigurationBuilder<T> setMonitorInterval(final String intervalSeconds)
         return this;
     }
 
+    @Override
+    public ConfigurationBuilder<T> setMonitorUris(final String monitorUris) {
+        this.monitorUris = monitorUris;
+        return this;
+    }
+
     @Override
     public ConfigurationBuilder<T> setPackages(final String packages) {
         this.packages = packages;