feat(id): include instance ID in hash ID, return instance ID via mbean-invoke

src/main/java/io/cryostat/agent/Agent.java

@@ -17,6 +17,7 @@
 
 import java.io.IOException;
 import java.lang.instrument.Instrumentation;
+import java.lang.management.ManagementFactory;
 import java.net.URI;
 import java.net.URISyntaxException;
 import java.nio.file.Path;
@@ -36,6 +37,8 @@
 
 import javax.inject.Named;
 import javax.inject.Singleton;
+import javax.management.MBeanServer;
+import javax.management.ObjectName;
 
 import io.cryostat.agent.ConfigModule.URIRange;
 import io.cryostat.agent.VersionInfo.Semver;
@@ -44,6 +47,7 @@
 import io.cryostat.agent.model.PluginInfo;
 import io.cryostat.agent.shaded.ShadeLogger;
 import io.cryostat.agent.triggers.TriggerEvaluator;
+import io.cryostat.libcryostat.net.CryostatAgentMXBean;
 
 import com.sun.tools.attach.AgentInitializationException;
 import com.sun.tools.attach.AgentLoadException;
@@ -240,6 +244,10 @@ public void accept(AgentArgs args) {
         try {
             final Client client = DaggerAgent_Client.builder().build();
 
+            CryostatAgentMXBean mxBean = client.agentMXBean();
+            MBeanServer mbs = ManagementFactory.getPlatformMBeanServer();
+            mbs.registerMBean(mxBean, new ObjectName(CryostatAgentMXBean.OBJECT_NAME));
+
             boolean sample = client.fleetSampleValue() < client.fleetSamplingRatio();
             log.trace(
                     "fleetSampleValue: {} , fleetSampleRatio: {}",
@@ -378,6 +386,8 @@ interface Client {
         @Named(ConfigModule.CRYOSTAT_AGENT_BASEURI_RANGE)
         URIRange uriRange();
 
+        CryostatAgent agentMXBean();
+
         WebServer webServer();
 
         Registration registration();

src/main/java/io/cryostat/agent/ConfigModule.java

@@ -50,6 +50,7 @@
 
 import io.cryostat.agent.util.ResourcesUtil;
 import io.cryostat.agent.util.StringUtils;
+import io.cryostat.libcryostat.net.CryostatAgentMXBean;
 
 import dagger.Module;
 import dagger.Provides;
@@ -819,6 +820,13 @@ public static String provideCryostatAgentInstanceId(Config config) {
                 .orElseGet(() -> UUID.randomUUID().toString());
     }
 
+    @Provides
+    @Singleton
+    public static CryostatAgentMXBean provideCryostatAgentMXBean(
+            @Named(CRYOSTAT_AGENT_INSTANCE_ID) String id) {
+        return new CryostatAgent(id);
+    }
+
     @Provides
     @Singleton
     @Named(CRYOSTAT_AGENT_APP_NAME)

src/main/java/io/cryostat/agent/CryostatAgent.java

@@ -0,0 +1,36 @@
+/*
+ * Copyright The Cryostat Authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package io.cryostat.agent;
+
+import javax.inject.Inject;
+import javax.inject.Named;
+
+import io.cryostat.libcryostat.net.CryostatAgentMXBean;
+
+public class CryostatAgent implements CryostatAgentMXBean {
+
+    private final String id;
+
+    @Inject
+    CryostatAgent(@Named(ConfigModule.CRYOSTAT_AGENT_INSTANCE_ID) String id) {
+        this.id = id;
+    }
+
+    @Override
+    public String getId() {
+        return id.toString();
+    }
+}

src/main/java/io/cryostat/agent/MainModule.java

@@ -825,9 +825,9 @@ public static FlightRecorderHelper provideFlightRecorderHelper() {
     @Provides
     @Singleton
     @Named(JVM_ID)
-    public static String provideJvmId() {
+    public static String provideJvmId(@Named(ConfigModule.CRYOSTAT_AGENT_INSTANCE_ID) String id) {
         try {
-            return JvmIdentifier.getLocal().getHash();
+            return JvmIdentifier.getLocal(id).getHash();
         } catch (IDException e) {
             throw new RuntimeException(e);
         }

src/main/java/io/cryostat/agent/remote/InvokeContext.java

@@ -19,6 +19,7 @@
 import java.io.InputStream;
 import java.io.OutputStream;
 import java.lang.management.ManagementFactory;
+import java.nio.file.Files;
 import java.nio.file.Paths;
 import java.util.Objects;
 import java.util.UUID;
@@ -45,7 +46,6 @@ class InvokeContext extends MutatingRemoteContext {
 
     private static final String DUMP_THREADS = "threadPrint";
     private static final String DUMP_THREADS_TO_FIlE = "threadDumpToFile";
-    private static final String DIAGNOSTIC_BEAN_NAME = "com.sun.management:type=DiagnosticCommand";
     private final Logger log = LoggerFactory.getLogger(getClass());
     private final ObjectMapper mapper;
 
@@ -74,7 +74,12 @@ public void handle(HttpExchange exchange) throws IOException {
                                 mapper.readValue(body, MBeanInvocationRequest.class);
                         String requestId = "";
                         String filename =
-                                config.getValue(ConfigModule.CRYOSTAT_AGENT_APP_NAME, String.class);
+                                Files.createTempFile(
+                                                config.getValue(
+                                                        ConfigModule.CRYOSTAT_AGENT_APP_NAME,
+                                                        String.class),
+                                                (String) null)
+                                        .toString();
                         if (!req.isValid()) {
                             exchange.sendResponseHeaders(
                                     HttpStatus.SC_BAD_REQUEST, BODY_LENGTH_NONE);
@@ -138,16 +143,24 @@ static class MBeanInvocationRequest<T> {
         public Object[] parameters;
         public String[] signature;
 
+        private static final String CRYOSTAT_AGENT_BEAN_NAME =
+                "io.cryostat.agent.CryostatAgent:name=agent";
         private static final String HOTSPOT_DIAGNOSTIC_BEAN_NAME =
                 "com.sun.management:type=HotSpotDiagnostic";
+        private static final String DIAGNOSTIC_COMMAND_BEAN_NAME =
+                "com.sun.management:type=DiagnosticCommand";
 
         public boolean isValid() {
-            if (this.beanName.equals(ManagementFactory.MEMORY_MXBEAN_NAME)
-                    || this.beanName.equals(HOTSPOT_DIAGNOSTIC_BEAN_NAME)) {
+            if (CRYOSTAT_AGENT_BEAN_NAME.equals(beanName)) {
                 return true;
-            } else if (this.beanName.equals(DIAGNOSTIC_BEAN_NAME)
-                    && (this.operation.equals(DUMP_THREADS)
-                            || this.operation.equals(DUMP_THREADS_TO_FIlE))) {
+            }
+            if (ManagementFactory.MEMORY_MXBEAN_NAME.equals(beanName)
+                    || HOTSPOT_DIAGNOSTIC_BEAN_NAME.equals(beanName)) {
+                return true;
+            }
+            if (DIAGNOSTIC_COMMAND_BEAN_NAME.equals(beanName)
+                    && (DUMP_THREADS.equals(this.operation)
+                            || DUMP_THREADS_TO_FIlE.equals(this.operation))) {
                 return true;
             }
             return false;