Start Jolokia agents if configured without modifying JVM options [CORDA-1042] (#2541)

* Jolokia agents are loaded dynamically if configured
* Renamed exportJmxTo (never used) to jmxMonitoringHttpPort and take it from config
* Updated documentation and tests

node/src/integration-test/kotlin/net/corda/node/amqp/AMQPBridgeTest.kt

@@ -138,7 +138,7 @@ class AMQPBridgeTest {
             doReturn("trustpass").whenever(it).trustStorePassword
             doReturn("cordacadevpass").whenever(it).keyStorePassword
             doReturn(artemisAddress).whenever(it).p2pAddress
-            doReturn("").whenever(it).exportJMXto
+            doReturn(null).whenever(it).jmxMonitoringHttpPort
             doReturn(emptyList<CertChainPolicyConfig>()).whenever(it).certificateChainCheckPolicies
         }
         artemisConfig.configureWithDevSSLCertificate()

node/src/integration-test/kotlin/net/corda/node/amqp/ProtonWrapperTests.kt

@@ -222,7 +222,7 @@ class ProtonWrapperTests {
             doReturn("trustpass").whenever(it).trustStorePassword
             doReturn("cordacadevpass").whenever(it).keyStorePassword
             doReturn(NetworkHostAndPort("0.0.0.0", artemisPort)).whenever(it).p2pAddress
-            doReturn("").whenever(it).exportJMXto
+            doReturn(null).whenever(it).jmxMonitoringHttpPort
             doReturn(emptyList<CertChainPolicyConfig>()).whenever(it).certificateChainCheckPolicies
         }
         artemisConfig.configureWithDevSSLCertificate()

node/src/main/kotlin/net/corda/node/internal/AbstractNode.kt

@@ -59,6 +59,8 @@ import net.corda.node.services.vault.NodeVaultService
 import net.corda.node.services.vault.VaultSoftLockManager
 import net.corda.node.shell.InteractiveShell
 import net.corda.node.utilities.AffinityExecutor
+import net.corda.node.utilities.NodeBuildProperties
+import net.corda.node.utilities.JVMAgentRegistry
 import net.corda.nodeapi.internal.DevIdentityGenerator
 import net.corda.nodeapi.internal.crypto.X509Utilities
 import net.corda.nodeapi.internal.persistence.CordaPersistence
@@ -73,6 +75,7 @@ import rx.Observable
 import rx.Scheduler
 import java.io.IOException
 import java.lang.reflect.InvocationTargetException
+import java.nio.file.Paths
 import java.security.KeyPair
 import java.security.KeyStoreException
 import java.security.PublicKey
@@ -192,6 +195,7 @@ abstract class AbstractNode(val configuration: NodeConfiguration,
         check(started == null) { "Node has already been started" }
         log.info("Node starting up ...")
         initCertificate()
+        initialiseJVMAgents()
         val schemaService = NodeSchemaService(cordappLoader.cordappSchemas, configuration.notary != null)
         val (identity, identityKeyPair) = obtainIdentity(notaryConfig = null)
         val identityService = makeIdentityService(identity.certificate)
@@ -749,6 +753,22 @@ abstract class AbstractNode(val configuration: NodeConfiguration,
         return NodeVaultService(platformClock, keyManagementService, stateLoader, hibernateConfig)
     }
 
+    /** Load configured JVM agents */
+    private fun initialiseJVMAgents() {
+        configuration.jmxMonitoringHttpPort?.let { port ->
+            requireNotNull(NodeBuildProperties.JOLOKIA_AGENT_VERSION) {
+                "'jolokiaAgentVersion' missing from build properties"
+            }
+            log.info("Starting Jolokia agent on HTTP port: $port")
+            val libDir = Paths.get(configuration.baseDirectory.toString(), "drivers")
+            val jarFilePath = JVMAgentRegistry.resolveAgentJar(
+                    "jolokia-jvm-${NodeBuildProperties.JOLOKIA_AGENT_VERSION}-agent.jar", libDir) ?:
+                    throw Error("Unable to locate agent jar file")
+            log.info("Agent jar file: $jarFilePath")
+            JVMAgentRegistry.attach("jolokia", "port=$port", jarFilePath)
+        }
+    }
+
     private inner class ServiceHubInternalImpl(
             override val identityService: IdentityService,
             // Place the long term identity key in the KMS. Eventually, this is likely going to be separated again because

node/src/main/kotlin/net/corda/node/internal/Node.kt

@@ -192,9 +192,9 @@ open class Node(configuration: NodeConfiguration,
                 val rpcBrokerDirectory: Path = baseDirectory / "brokers" / "rpc"
                 with(rpcOptions) {
                     rpcBroker = if (useSsl) {
-                        ArtemisRpcBroker.withSsl(this.address!!, sslConfig, securityManager, certificateChainCheckPolicies, networkParameters.maxMessageSize, exportJMXto.isNotEmpty(), rpcBrokerDirectory)
+                        ArtemisRpcBroker.withSsl(this.address!!, sslConfig, securityManager, certificateChainCheckPolicies, networkParameters.maxMessageSize, jmxMonitoringHttpPort != null, rpcBrokerDirectory)
                     } else {
-                        ArtemisRpcBroker.withoutSsl(this.address!!, adminAddress!!, sslConfig, securityManager, certificateChainCheckPolicies, networkParameters.maxMessageSize, exportJMXto.isNotEmpty(), rpcBrokerDirectory)
+                        ArtemisRpcBroker.withoutSsl(this.address!!, adminAddress!!, sslConfig, securityManager, certificateChainCheckPolicies, networkParameters.maxMessageSize, jmxMonitoringHttpPort != null, rpcBrokerDirectory)
                     }
                 }
                 return rpcBroker!!.addresses

node/src/main/kotlin/net/corda/node/services/config/NodeConfiguration.kt

@@ -25,7 +25,7 @@ val Int.MB: Long get() = this * 1024L * 1024L
 interface NodeConfiguration : NodeSSLConfiguration {
     val myLegalName: CordaX500Name
     val emailAddress: String
-    val exportJMXto: String
+    val jmxMonitoringHttpPort: Int?
     val dataSourceProperties: Properties
     val rpcUsers: List<User>
     val security: SecurityConfiguration?
@@ -118,6 +118,7 @@ data class NodeConfigurationImpl(
         /** This is not retrieved from the config file but rather from a command line argument. */
         override val baseDirectory: Path,
         override val myLegalName: CordaX500Name,
+        override val jmxMonitoringHttpPort: Int? = null,
         override val emailAddress: String,
         override val keyStorePassword: String,
         override val trustStorePassword: String,
@@ -184,7 +185,6 @@ data class NodeConfigurationImpl(
         return errors
     }
 
-    override val exportJMXto: String get() = "http"
     override val transactionCacheSizeBytes: Long
         get() = transactionCacheSizeMegaBytes?.MB ?: super.transactionCacheSizeBytes
     override val attachmentContentCacheSizeBytes: Long

node/src/main/kotlin/net/corda/node/services/messaging/ArtemisMessagingServer.kt

@@ -144,7 +144,7 @@ class ArtemisMessagingServer(private val config: NodeConfiguration,
         managementNotificationAddress = SimpleString(NOTIFICATIONS_ADDRESS)
 
         // JMX enablement
-        if (config.exportJMXto.isNotEmpty()) {
+        if (config.jmxMonitoringHttpPort != null) {
             isJMXManagementEnabled = true
             isJMXUseBrokerName = true
         }

node/src/main/kotlin/net/corda/node/utilities/JVMAgentRegistry.kt

@@ -0,0 +1,50 @@
+package net.corda.node.utilities
+
+import com.ea.agentloader.AgentLoader
+import net.corda.core.internal.exists
+import net.corda.core.internal.isRegularFile
+import java.net.URLClassLoader
+import java.nio.file.Path
+import java.nio.file.Paths
+import java.util.concurrent.ConcurrentHashMap
+
+/**
+ * Helper class for loading JVM agents dynamically
+ */
+object JVMAgentRegistry {
+
+    /**
+     * Names and options of loaded agents
+     */
+    val loadedAgents = ConcurrentHashMap<String, String>()
+
+    /**
+     * Load and attach agent located at given [jar], unless [loadedAgents]
+     * indicate that one of its instance has been already loaded.
+     */
+    fun attach(agentName: String, options: String, jar: Path) {
+        loadedAgents.computeIfAbsent(agentName.toLowerCase()) {
+            AgentLoader.loadAgent(jar.toString(), options)
+            options
+        }
+    }
+
+    /**
+     * Attempt finding location of jar for given agent by first searching into
+     * "drivers" directory of [nodeBaseDirectory] and then falling back to
+     * classpath. Returns null if no match is found.
+     */
+    fun resolveAgentJar(jarFileName: String, driversDir: Path): Path? {
+        require(jarFileName.endsWith(".jar")) { "jarFileName does not have .jar suffix" }
+
+        val path = Paths.get(driversDir.toString(), jarFileName)
+        return if (path.exists() && path.isRegularFile()) {
+            path
+        } else {
+            (this::class.java.classLoader as? URLClassLoader)
+                ?.urLs
+                ?.map { Paths.get(it.path) }
+                ?.firstOrNull { it.fileName.toString() == jarFileName }
+        }
+    }
+}

node/src/main/kotlin/net/corda/node/utilities/NodeBuildProperties.kt

@@ -0,0 +1,27 @@
+package net.corda.node.utilities
+
+import java.util.*
+
+/**
+ * Expose properties defined in top-level 'constants.properties' file.
+ */
+object NodeBuildProperties {
+
+    // Note: initialization order is important
+    private val data by lazy {
+        Properties().apply {
+            NodeBuildProperties::class.java.getResourceAsStream("/build.properties")
+                    ?.let { load(it) }
+        }
+    }
+
+    /**
+     * Jolokia dependency version
+     */
+    val JOLOKIA_AGENT_VERSION = get("jolokiaAgentVersion")
+
+    /**
+     * Get property value by name
+     */
+    fun get(key: String): String? = data.getProperty(key)
+}

node/src/main/resources/build.properties

@@ -0,0 +1,5 @@
+# Build constants exported as resource file to make them visible in Node program
+# Note: sadly, due to present limitation of IntelliJ-IDEA in processing resource files, these constants cannot be
+# imported from top-level 'constants.properties' file
+
+jolokiaAgentVersion=1.3.7

node/src/test/kotlin/net/corda/node/services/messaging/ArtemisMessagingTest.kt

@@ -67,7 +67,7 @@ class ArtemisMessagingTest {
             doReturn("trustpass").whenever(it).trustStorePassword
             doReturn("cordacadevpass").whenever(it).keyStorePassword
             doReturn(NetworkHostAndPort("0.0.0.0", serverPort)).whenever(it).p2pAddress
-            doReturn("").whenever(it).exportJMXto
+            doReturn(null).whenever(it).jmxMonitoringHttpPort
             doReturn(emptyList<CertChainPolicyConfig>()).whenever(it).certificateChainCheckPolicies
             doReturn(5).whenever(it).messageRedeliveryDelaySeconds
         }