CORDA-1979 Cleanup NodeStartup for better readability (#3946)

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

@@ -67,64 +67,87 @@ open class NodeStartup: CordaCliWrapper("corda", "Runs a Corda Node") {
      */
     override fun runProgram(): Int {
         val startTime = System.currentTimeMillis()
-        if (!canNormalizeEmptyPath()) {
-            println("You are using a version of Java that is not supported (${System.getProperty("java.version")}). Please upgrade to the latest supported version.")
-            println("Corda will now exit...")
-            return ExitCodes.FAILURE
-        }
+        // Step 1. Check for supported Java version.
+        if (!isValidJavaVersion()) return ExitCodes.FAILURE
 
-        val registrationMode = checkRegistrationMode()
-
-        // TODO: Reconsider if automatic re-registration should be applied when something failed during initial registration.
-        //      There might be cases where the node user should investigate what went wrong before registering again.
-        if (registrationMode && !cmdLineOptions.isRegistration) {
-            println("Node was started before with `--initial-registration`, but the registration was not completed.\nResuming registration.")
-            // Pretend that the node was started with `--initial-registration` to help prevent user error.
-            cmdLineOptions.isRegistration = true
-        }
-
-        // We do the single node check before we initialise logging so that in case of a double-node start it
+        // Step 2. We do the single node check before we initialise logging so that in case of a double-node start it
         // doesn't mess with the running node's logs.
         enforceSingleNodeIsRunning(cmdLineOptions.baseDirectory)
 
+        // Step 3. Initialise logging.
         initLogging()
-        // Register all cryptography [Provider]s.
+
+        // Step 4. Register all cryptography [Provider]s.
         // Required to install our [SecureRandom] before e.g., UUID asks for one.
         // This needs to go after initLogging(netty clashes with our logging).
         Crypto.registerProviders()
 
+        // Step 5. Print banner and basic node info.
         val versionInfo = getVersionInfo()
-
         drawBanner(versionInfo)
         Node.printBasicNodeInfo(LOGS_CAN_BE_FOUND_IN_STRING, System.getProperty("log-path"))
 
+        // Step 6. Load and validate node configuration.
         val configuration = (attempt { loadConfiguration() }.doOnException(handleConfigurationLoadingError(cmdLineOptions.configFile)) as? Try.Success)?.let(Try.Success<NodeConfiguration>::value) ?: return ExitCodes.FAILURE
-
         val errors = configuration.validate()
         if (errors.isNotEmpty()) {
             logger.error("Invalid node configuration. Errors were:${System.lineSeparator()}${errors.joinToString(System.lineSeparator())}")
             return ExitCodes.FAILURE
         }
 
+        // Step 7. Configuring special serialisation requirements, i.e., bft-smart relies on Java serialization.
         attempt { banJavaSerialisation(configuration) }.doOnException { error -> error.logAsUnexpected("Exception while configuring serialisation") } as? Try.Success ?: return ExitCodes.FAILURE
 
+        // Step 8. Any actions required before starting up the Corda network layer.
         attempt { preNetworkRegistration(configuration) }.doOnException(handleRegistrationError) as? Try.Success ?: return ExitCodes.FAILURE
 
-        cmdLineOptions.nodeRegistrationOption?.let {
-            // Null checks for [compatibilityZoneURL], [rootTruststorePath] and [rootTruststorePassword] has been done in [CmdLineOptions.loadConfig]
-            attempt { registerWithNetwork(configuration, versionInfo, it) }.doOnException(handleRegistrationError) as? Try.Success ?: return ExitCodes.FAILURE
-            // At this point the node registration was successful. We can delete the marker file.
-            deleteNodeRegistrationMarker(cmdLineOptions.baseDirectory)
-            return ExitCodes.SUCCESS
+        // Step 9. Check if in registration mode.
+        checkAndRunRegistrationMode(configuration, versionInfo)?.let {
+            return if (it) ExitCodes.SUCCESS
+            else ExitCodes.FAILURE
         }
 
+        // Step 10. Log startup info.
         logStartupInfo(versionInfo, configuration)
 
+        // Step 11. Start node: create the node, check for other command-line options, add extra logging etc.
         attempt { startNode(configuration, versionInfo, startTime) }.doOnSuccess { logger.info("Node exiting successfully") }.doOnException(handleStartError) as? Try.Success ?: return ExitCodes.FAILURE
 
         return ExitCodes.SUCCESS
     }
 
+    private fun checkAndRunRegistrationMode(configuration: NodeConfiguration, versionInfo: VersionInfo): Boolean? {
+        checkUnfinishedRegistration()
+        cmdLineOptions.nodeRegistrationOption?.let {
+            // Null checks for [compatibilityZoneURL], [rootTruststorePath] and [rootTruststorePassword] has been done in [CmdLineOptions.loadConfig]
+            attempt { registerWithNetwork(configuration, versionInfo, it) }.doOnException(handleRegistrationError) as? Try.Success
+                    ?: return false
+            // At this point the node registration was successful. We can delete the marker file.
+            deleteNodeRegistrationMarker(cmdLineOptions.baseDirectory)
+            return true
+        }
+        return null
+    }
+
+    private fun isValidJavaVersion(): Boolean {
+        if (!canNormalizeEmptyPath()) {
+            println("You are using a version of Java that is not supported (${System.getProperty("java.version")}). Please upgrade to the latest supported version.")
+            println("Corda will now exit...")
+            return false
+        }
+        return true
+    }
+
+    // TODO: Reconsider if automatic re-registration should be applied when something failed during initial registration.
+    //      There might be cases where the node user should investigate what went wrong before registering again.
+    private fun checkUnfinishedRegistration() {
+        if (checkRegistrationMode() && !cmdLineOptions.isRegistration) {
+            println("Node was started before with `--initial-registration`, but the registration was not completed.\nResuming registration.")
+            // Pretend that the node was started with `--initial-registration` to help prevent user error.
+            cmdLineOptions.isRegistration = true
+        }
+    }
+
     private fun <RESULT> attempt(action: () -> RESULT): Try<RESULT> = Try.on(action)
 
     private fun Exception.isExpectedWhenStartingNode() = startNodeExpectedErrors.any { error -> error.isInstance(this) }
@@ -272,6 +295,7 @@ open class NodeStartup: CordaCliWrapper("corda", "Runs a Corda Node") {
         logLoadedCorDapps(node.services.cordappProvider.cordapps)
 
         node.nodeReadyFuture.thenMatch({
+            // Elapsed time in seconds. We used 10 / 100.0 and not directly / 1000.0 to only keep two decimal digits.
             val elapsed = (System.currentTimeMillis() - startTime) / 10 / 100.0
             val name = nodeInfo.legalIdentitiesAndCerts.first().name.organisation
             Node.printBasicNodeInfo("Node for \"$name\" started up and registered in $elapsed sec")