Support Jenkins restart (#1039)

* Support Jenkins restart

* Support Jenkins restart

Author: cyrille-leclerc

src/main/java/io/jenkins/plugins/opentelemetry/JenkinsOpenTelemetryPluginConfiguration.java

@@ -16,6 +16,7 @@
 import hudson.PluginWrapper;
 import hudson.init.InitMilestone;
 import hudson.init.Initializer;
+import hudson.init.Terminator;
 import hudson.model.Describable;
 import hudson.model.Descriptor;
 import hudson.tasks.BuildStep;
@@ -716,6 +717,11 @@ public FormValidation doCheckExportOtelConfigurationAsEnvironmentVariables(@Quer
         return FormValidation.warning("Note that OpenTelemetry credentials, if configured, will be exposed as environment variables (likely in OTEL_EXPORTER_OTLP_HEADERS)");
     }
 
+    /**
+     * Close the @link LogStorageRetriever}.
+     * As <code>@PreDestroy</code> doesn't seem to be honored by Jenkins, we use <code>@Terminator</code> in addition.
+     */
+    @Terminator
     @PreDestroy
     public void preDestroy() throws Exception {
         if (logStorageRetriever != null) {

src/main/java/io/jenkins/plugins/opentelemetry/init/OtelJulHandler.java

@@ -6,6 +6,7 @@
 package io.jenkins.plugins.opentelemetry.init;
 
 import hudson.Extension;
+import hudson.init.Terminator;
 import io.jenkins.plugins.opentelemetry.api.OpenTelemetryLifecycleListener;
 import io.jenkins.plugins.opentelemetry.api.ReconfigurableOpenTelemetry;
 import io.opentelemetry.api.common.Attributes;
@@ -19,6 +20,7 @@
 import jenkins.YesNoMaybe;
 
 import javax.annotation.PostConstruct;
+import javax.annotation.PreDestroy;
 import javax.inject.Inject;
 import java.io.PrintWriter;
 import java.io.StringWriter;
@@ -175,7 +177,18 @@ public void postConstruct() {
         this.loggerProvider = openTelemetry.getLogsBridge();
         this.captureExperimentalAttributes = openTelemetry.getConfig().getBoolean("otel.instrumentation.java-util-logging.experimental-log-attributes", false);
         Logger.getLogger("").addHandler(this);
-        logger.log(Level.FINE, "Otel java.util.logging bridge initialized");
+        logger.log(Level.INFO, "OTel logging Handler registered on java.util.logging");
+    }
+
+    /**
+     * Unregister the java.util.logging handler.
+     * As <code>@PreDestroy</code> doesn't seem to be honored by Jenkins, we use <code>@Terminator</code> in addition.
+     */
+    @Terminator
+    @PreDestroy
+    public void preDestroy() {
+        Logger.getLogger("").removeHandler(this);
+        logger.log(Level.INFO, "OTel logging Handler unregistered from java.util.logging");
     }
 
     /**

src/main/java/io/jenkins/plugins/opentelemetry/init/ServletFilterInitializer.java

@@ -6,13 +6,15 @@
 package io.jenkins.plugins.opentelemetry.init;
 
 import hudson.Extension;
+import hudson.init.Terminator;
 import hudson.util.PluginServletFilter;
 import io.jenkins.plugins.opentelemetry.api.OpenTelemetryLifecycleListener;
 import io.jenkins.plugins.opentelemetry.servlet.StaplerInstrumentationServletFilter;
 import io.jenkins.plugins.opentelemetry.servlet.TraceContextServletFilter;
 import jenkins.YesNoMaybe;
 
 import javax.annotation.PostConstruct;
+import javax.annotation.PreDestroy;
 import javax.inject.Inject;
 import jakarta.servlet.Filter;
 import jakarta.servlet.ServletException;
@@ -40,6 +42,17 @@ public void postConstruct() {
         addToPluginServletFilter(staplerInstrumentationServletFilter);
     }
 
+    /**
+     * Unregister the {@link Filter}s from the {@link PluginServletFilter}.
+     * As <code>@PreDestroy</code> doesn't seem to be honored by Jenkins, we use <code>@Terminator</code> in addition.
+     */
+    @Terminator
+    @PreDestroy
+    public void preDestroy() throws ServletException {
+        PluginServletFilter.removeFilter(traceContextServletFilter);
+        PluginServletFilter.removeFilter(staplerInstrumentationServletFilter);
+    }
+
     private void addToPluginServletFilter(Filter filter) {
         if (PluginServletFilter.hasFilter(filter)) {
             logger.log(Level.INFO, () -> filter.getClass().getName() + " already enabled");