fix(registration): JMX URL defaults to reusing callback host part (cr…

…yostatio#414)

README.md

@@ -184,6 +184,8 @@ and how it advertises itself to a Cryostat server instance. Properties that requ
 - [ ] `cryostat.agent.app.name` [`String`]: a human-friendly name for this application. Default `cryostat-agent`.
 - [ ] `cryostat.agent.app.jmx.port` [`int`]: the JMX RMI port that the application is listening on. The default is to attempt to determine this from the `com.sun.management.jmxremote.port` system property.
 - [ ] `cryostat.agent.registration.retry-ms` [`long`]: the duration in milliseconds between attempts to register with the Cryostat server. Default `5000`.
+- [ ] `cryostat.agent.registration.jmx.ignore` [`boolean`]: if the Agent detects that the host JVM has its JMX server enabled, then setting this property to `true` will cause the Agent to ignore the JMX server and not publish a JMX Service URL after registering with the Cryostat server. Default `false`.
+- [ ] `cryostat.agent.registration.jmx.use-callback-host` [`boolean`]: if the Agent should use the host part of the callback URL when constructing the JMX Service URL for registration. If set to `false` then the URL will contain the automatically detected hostname instead. Default `true`.
 - [ ] `cryostat.agent.exit.signals` [`[String]`]: a comma-separated list of signals that the agent should handle. When any of these signals is caught the agent initiates an orderly shutdown, deregistering from the Cryostat server and potentially uploading the latest harvested JFR data. Default `INT,TERM`.
 - [ ] `cryostat.agent.exit.deregistration.timeout-ms` [`long`]: the duration in milliseconds to wait for a response from the Cryostat server when attempting to deregister at shutdown time . Default `3000`.
 - [ ] `cryostat.agent.harvester.period-ms` [`long`]: the length of time between JFR collections and pushes by the harvester. This also controls the maximum age of data stored in the buffer for the harvester's managed Flight Recording. Every `period-ms` the harvester will upload a JFR binary file to the `cryostat.agent.baseuri` archives. Default `-1`, which indicates no scheduled harvest uploading will be performed.

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

@@ -85,6 +85,10 @@ public abstract class ConfigModule {
             "cryostat.agent.registration.retry-ms";
     public static final String CRYOSTAT_AGENT_REGISTRATION_CHECK_MS =
             "cryostat.agent.registration.check-ms";
+    public static final String CRYOSTAT_AGENT_REGISTRATION_JMX_IGNORE =
+            "cryostat.agent.registration.jmx.ignore";
+    public static final String CRYOSTAT_AGENT_REGISTRATION_JMX_USE_CALLBACK_HOST =
+            "cryostat.agent.registration.jmx.use-callback-host";
     public static final String CRYOSTAT_AGENT_EXIT_SIGNALS = "cryostat.agent.exit.signals";
     public static final String CRYOSTAT_AGENT_EXIT_DEREGISTRATION_TIMEOUT_MS =
             "cryostat.agent.exit.deregistration.timeout-ms";
@@ -316,6 +320,20 @@ public static int provideCryostatAgentRegistrationCheckMs(Config config) {
         return config.getValue(CRYOSTAT_AGENT_REGISTRATION_CHECK_MS, int.class);
     }
 
+    @Provides
+    @Singleton
+    @Named(CRYOSTAT_AGENT_REGISTRATION_JMX_IGNORE)
+    public static boolean provideCryostatAgentRegistrationJmxIgnore(Config config) {
+        return config.getValue(CRYOSTAT_AGENT_REGISTRATION_JMX_IGNORE, boolean.class);
+    }
+
+    @Provides
+    @Singleton
+    @Named(CRYOSTAT_AGENT_REGISTRATION_JMX_USE_CALLBACK_HOST)
+    public static boolean provideCryostatAgentRegistrationJmxUseCallbackHost(Config config) {
+        return config.getValue(CRYOSTAT_AGENT_REGISTRATION_JMX_USE_CALLBACK_HOST, boolean.class);
+    }
+
     @Provides
     @Singleton
     @Named(CRYOSTAT_AGENT_HARVESTER_PERIOD_MS)

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

@@ -221,8 +221,11 @@ public static Registration provideRegistration(
             @Named(ConfigModule.CRYOSTAT_AGENT_HOSTNAME) String hostname,
             @Named(ConfigModule.CRYOSTAT_AGENT_APP_JMX_PORT) int jmxPort,
             @Named(ConfigModule.CRYOSTAT_AGENT_REGISTRATION_RETRY_MS) int registrationRetryMs,
-            @Named(ConfigModule.CRYOSTAT_AGENT_REGISTRATION_CHECK_MS) int registrationCheckMs) {
-
+            @Named(ConfigModule.CRYOSTAT_AGENT_REGISTRATION_CHECK_MS) int registrationCheckMs,
+            @Named(ConfigModule.CRYOSTAT_AGENT_REGISTRATION_JMX_IGNORE)
+                    boolean registrationJmxIgnore,
+            @Named(ConfigModule.CRYOSTAT_AGENT_REGISTRATION_JMX_USE_CALLBACK_HOST)
+                    boolean registrationJmxUseCallbackHost) {
         Logger log = LoggerFactory.getLogger(Registration.class);
         return new Registration(
                 Executors.newSingleThreadScheduledExecutor(
@@ -249,7 +252,9 @@ public static Registration provideRegistration(
                 hostname,
                 jmxPort,
                 registrationRetryMs,
-                registrationCheckMs);
+                registrationCheckMs,
+                registrationJmxIgnore,
+                registrationJmxUseCallbackHost);
     }
 
     @Provides

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

@@ -59,6 +59,8 @@ public class Registration {
     private final int jmxPort;
     private final int registrationRetryMs;
     private final int registrationCheckMs;
+    private final boolean registrationJmxIgnore;
+    private final boolean registrationJmxUseCallbackHost;
 
     private final PluginInfo pluginInfo = new PluginInfo();
     private final Set<Consumer<RegistrationEvent>> listeners = new HashSet<>();
@@ -77,7 +79,9 @@ public class Registration {
             String hostname,
             int jmxPort,
             int registrationRetryMs,
-            int registrationCheckMs) {
+            int registrationCheckMs,
+            boolean registrationJmxIgnore,
+            boolean registrationJmxUseCallbackHost) {
         this.executor = executor;
         this.cryostat = cryostat;
         this.callback = callback;
@@ -90,6 +94,8 @@ public class Registration {
         this.jmxPort = jmxPort;
         this.registrationRetryMs = registrationRetryMs;
         this.registrationCheckMs = registrationCheckMs;
+        this.registrationJmxIgnore = registrationJmxIgnore;
+        this.registrationJmxUseCallbackHost = registrationJmxUseCallbackHost;
     }
 
     void start() {
@@ -296,12 +302,13 @@ private Set<DiscoveryNode> defineSelf() throws UnknownHostException, URISyntaxEx
         discoveryNodes.add(
                 new DiscoveryNode(appName + "-agent-" + pluginInfo.getId(), NODE_TYPE, httpSelf));
 
-        if (jmxPort > 0) {
+        if (!registrationJmxIgnore && jmxPort > 0) {
             uri =
                     URI.create(
                             String.format(
                                     "service:jmx:rmi:///jndi/rmi://%s:%d/jmxrmi",
-                                    hostname, jmxPort));
+                                    registrationJmxUseCallbackHost ? uri.getHost() : hostname,
+                                    jmxPort));
             port = jmxPort;
             DiscoveryNode.Target jmxSelf =
                     new DiscoveryNode.Target(

src/main/resources/META-INF/microprofile-config.properties

@@ -23,6 +23,8 @@ cryostat.agent.realm=
 cryostat.agent.exit.signals=INT,TERM
 cryostat.agent.registration.retry-ms=5000
 cryostat.agent.registration.check-ms=60000
+cryostat.agent.registration.jmx.ignore=false
+cryostat.agent.registration.jmx.use-callback-host=true
 cryostat.agent.exit.deregistration.timeout-ms=3000
 
 cryostat.agent.harvester.period-ms=-1