feat: Set application name via command line with the .msi installer (#2648)

* Initial code

* InnerText, not Value

* Working solution for setting app pool naming

* Cleanup

Author: nr-ahemsath

src/Agent/MsiInstaller/Installer/Product.wxs

@@ -172,6 +172,7 @@ SPDX-License-Identifier: Apache-2.0
     <CustomAction Id="SaveDeferredCustomActionData" DllEntry="SaveDeferredCustomActionData" Execute="immediate" Return="check" BinaryRef="CustomActionsDll" />
     <CustomAction Id="MigrateConfiguration" DllEntry="MigrateConfiguration" Execute="deferred" Impersonate="no" Return="check" BinaryRef="CustomActionsDll" />
     <CustomAction Id="SetLicenseKey" DllEntry="SetLicenseKey" Execute="deferred" Impersonate="no" Return="check" BinaryRef="CustomActionsDll" />
+    <CustomAction Id="SetAppName" DllEntry="SetAppName" Execute="deferred" Impersonate="no" Return="check" BinaryRef="CustomActionsDll" />
     <CustomAction Id="CleanupPreviousInstall" DllEntry="CleanupPreviousInstall" Execute="deferred" Impersonate="no" Return="check" BinaryRef="CustomActionsDll" />
     <CustomAction Id="RestartIis" DllEntry="RestartIis" Impersonate="yes" BinaryRef="CustomActionsDll" />
     <CustomAction Id="CloseStatusMonitor" DllEntry="CloseStatusMonitor" Impersonate="yes" BinaryRef="CustomActionsDll" />

src/Agent/MsiInstaller/InstallerActions/CustomActions.cs

@@ -35,6 +35,8 @@ public static ActionResult SaveDeferredCustomActionData(Session session)
             var customActionData = new CustomActionData
             {
                 { "NR_LICENSE_KEY", session["NR_LICENSE_KEY"] },
+                { "NR_APP_NAME", session["NR_APP_NAME"] },
+                { "NR_USE_APP_POOL_NAMING", session["NR_USE_APP_POOL_NAMING"] },
                 { "NETAGENTCOMMONFOLDER", session["NETAGENTCOMMONFOLDER"] },
                 { "LOGSFOLDER", session["LOGSFOLDER"] },
                 { "NETAGENTFOLDER", session["NETAGENTFOLDER"] },
@@ -43,6 +45,7 @@ public static ActionResult SaveDeferredCustomActionData(Session session)
 
             session.DoAction("MigrateConfiguration", customActionData);
             session.DoAction("SetLicenseKey", customActionData);
+            session.DoAction("SetAppName", customActionData);
             session.DoAction("CleanupPreviousInstall", customActionData);
 
             return ActionResult.Success;
@@ -111,6 +114,84 @@ public static ActionResult SetLicenseKey(Session session)
             return ActionResult.Success;
         }
 
+        [CustomAction]
+        public static ActionResult SetAppName(Session session)
+        {
+            try
+            {
+                var path = session.CustomActionData["NETAGENTCOMMONFOLDER"] + @"\newrelic.config";
+
+                // appName will be an empty string if the property wasn't set via the command line,
+                // OR if the property was set with an empty string (NR_APP_NAME="")
+                var appName = session.CustomActionData["NR_APP_NAME"];
+                var useAppPoolNaming = session.CustomActionData["NR_USE_APP_POOL_NAMING"].Equals(bool.TrueString, StringComparison.CurrentCultureIgnoreCase)
+                    || session.CustomActionData["NR_USE_APP_POOL_NAMING"].Equals("1");
+
+                session.Log($"SetAppName: appName={appName}, useAppPoolNaming={useAppPoolNaming}");
+                if (string.IsNullOrEmpty(appName) && !useAppPoolNaming)
+                {
+                    session.Log("NR_APP_NAME was not set or was set to an empty string, and NR_USE_APP_POOL_NAMING was not set or was not set to true. Application name not modified.");
+                    return ActionResult.Success;
+                }
+
+                var document = new XmlDocument();
+                document.Load(path);
+                var namespaceManager = new XmlNamespaceManager(document.NameTable);
+                namespaceManager.AddNamespace("newrelic-config", "urn:newrelic-config");
+
+                var applicationNode = document.SelectSingleNode("/newrelic-config:configuration/newrelic-config:application", namespaceManager);
+                if (applicationNode == null)
+                {
+                    session.Log("Unable to locate /configuration/application node in newrelic.config. Application name not set.");
+                    return ActionResult.Success;
+                }
+
+                // NR_USE_APP_POOL_NAMING takes precedence over anything set in NR_APP_NAME
+                if (useAppPoolNaming)
+                {
+                    session.Log("NR_APP_NAME = UseAppPoolNaming, deleting name nodes from application element");
+                    var childNodes = applicationNode.ChildNodes;
+                    foreach (XmlNode childNode in childNodes)
+                    {
+                        session.Log($"found child node with name {childNode.Name}");
+                        if (childNode.Name.Equals("name"))
+                        {
+                            session.Log("Deleting 'name' node");
+                            applicationNode.RemoveChild(childNode);
+                        }
+                    }
+                    document.Save(session.CustomActionData["NETAGENTCOMMONFOLDER"] + @"\newrelic.config");
+                    session.Log("newrelic.config saved with application name elements removed.");
+                    return ActionResult.Success;
+                }
+
+                // If we get here, NR_USE_APP_POOL_NAMING was not set or not set to true,
+                // and NR_APP_NAME has a non-empty value. Set the app name to NR_APP_NAME.
+                // If no <name>appName</name> node exists, create it
+                XmlNode applicationNameNode;
+                applicationNameNode = document.SelectSingleNode("/newrelic-config:configuration/newrelic-config:application/newrelic-config:name", namespaceManager);
+                if (applicationNameNode == null)
+                {
+                    session.Log("Unable to locate existing /configuration/application/name node in newrelic.config, creating a new one.");
+                    var newNameNode = document.CreateElement("name", "urn:newrelic-config");
+                    applicationNameNode = applicationNode.AppendChild(newNameNode);
+                }
+                session.Log("/configuration/application/name node found or created in newrelic.config");
+
+                applicationNameNode.InnerText = appName;
+                session.Log("Application name set to " + appName);
+
+                document.Save(session.CustomActionData["NETAGENTCOMMONFOLDER"] + @"\newrelic.config");
+                session.Log("newrelic.config saved with updated application name.");
+            }
+            catch (Exception exception)
+            {
+                session.Log("Exception while attempting to set the application name in newrelic.config.\n{0}", exception);
+            }
+
+            return ActionResult.Success;
+        }
+
         [CustomAction]
         public static ActionResult CleanupPreviousInstall(Session session)
         {