Icinga2Agent.psm1: push latest version

contrib/windows-agent-installer/Icinga2Agent.psm1

@@ -20,11 +20,12 @@ function Icinga2AgentModule {
         [bool]$AgentAddFirewallRule       = $FALSE,
         [array]$ParentEndpoints,
         [array]$EndpointsConfig,
-        [array]$GlobalZones,
+        [array]$GlobalZones               = @( 'director-global' ),
 
         # Agent installation / update
         [string]$IcingaServiceUser,
         [string]$DownloadUrl              = 'https://packages.icinga.com/windows/',
+        [string]$AgentInstallDirectory,
         [bool]$AllowUpdates               = $FALSE,
         [array]$InstallerHashes,
         [bool]$FlushApiDirectory          = $FALSE,
@@ -41,7 +42,7 @@ function Icinga2AgentModule {
         [string]$DirectorPassword,
         [string]$DirectorDomain,
         [string]$DirectorAuthToken,
-        [string]$DirectorHostObject,
+        [System.Object]$DirectorHostObject,
         [bool]$DirectorDeployConfig       = $FALSE,
 
         # NSClient Installer
@@ -54,9 +55,13 @@ function Icinga2AgentModule {
 
         # Uninstaller arguments
         [bool]$FullUninstallation         = $FALSE,
+        [bool]$RemoveNSClient             = $FALSE,
 
         #Internal handling
-        [bool]$DebugMode                  = $FALSE
+        [switch]$RunInstaller             = $FALSE,
+        [switch]$RunUninstaller           = $FALSE,
+        [bool]$DebugMode                  = $FALSE,
+        [string]$ModuleLogFile
     );
 
     #
@@ -78,10 +83,11 @@ function Icinga2AgentModule {
         icinga_enable_debug_log = $IcingaEnableDebugLog;
         agent_add_firewall_rule = $AgentAddFirewallRule;
         parent_endpoints        = $ParentEndpoints;
-        endpoints_config         = $EndpointsConfig;
+        endpoints_config        = $EndpointsConfig;
         global_zones            = $GlobalZones;
         icinga_service_user     = $IcingaServiceUser;
         download_url            = $DownloadUrl;
+        agent_install_directory = $AgentInstallDirectory;
         allow_updates           = $AllowUpdates;
         installer_hashes        = $InstallerHashes;
         flush_api_directory     = $FlushApiDirectory;
@@ -103,7 +109,9 @@ function Icinga2AgentModule {
         nsclient_directory      = $NSClientDirectory;
         nsclient_installer_path = $NSClientInstallerPath;
         full_uninstallation     = $FullUninstallation;
+        remove_nsclient         = $RemoveNSClient;
         debug_mode              = $DebugMode;
+        module_log_file         = $ModuleLogFile;
     }
 
     #
@@ -173,7 +181,7 @@ function Icinga2AgentModule {
     # $this.setProperty('agent_version', '2.4.10')
     #
     $installer | Add-Member -membertype ScriptMethod -name 'setProperty' -value {
-        param([string] $key, [string]$value);
+        param([string]$key, $value);
 
         # Initialse some variables first
         # will only be called once
@@ -195,20 +203,81 @@ function Icinga2AgentModule {
     }
 
     #
-    # Print an exception message and wait 5 seconds
+    # Write all output from consoles to a logfile
-    # before continuing the execution. After each
+    #
-    # exception call we should ensure the script
+    $installer | Add-Member -membertype ScriptMethod -name 'writeLogFile' -value {
-    # ends with exit.
+        param([string]$severity, [string]$content);
-    # Todo: Adding exit 1 here results in an script
+
-    # error we should take care off before adding it
+        # If no logfile is specified, do nothing
-    # again
+        if (-Not $this.config('module_log_file')) {
-    # Deprecated: Do no longer use!
+            return;
+        }
+
+        # Store our logfile into a variable
+        $logFile = $this.config('module_log_file');
+
+        # Have we specified a directory to write into or a file already?
+        try {
+            # Check if we are a directory or a file
+            # Will return false for files or non-existing files
+            $directory = (Get-Item $logFile) -is [System.IO.DirectoryInfo];
+        } catch {
+            # Nothing to catch. Simply get rid of error messages from aboves function in case of error
+            # Will return false anyways on error
+        }
+
+        # If we are a directory, add a file we can write to
+        if ($directory) {
+            $logFile = Join-Path -Path $logFile -ChildPath 'icinga2agent_psmodule.log';
+        }
+
+        # Format a timestamp to get to know the exact date and time. Example: 2017-13-07 22:09:13.263.263
+        $timestamp = Get-Date -Format "yyyy-dd-MM HH:mm:ss.fff";
+        $content = [string]::Format('{0} [{1}]: {2}', $timestamp, $severity, $content);
+
+        # Write the content to our logfile
+        Add-Content -Path $logFile -Value $content;
+    }
+
+    #
+    # This function will print messages as errors, but add them internally to
+    # an exception list. These will re-printed at the end to summarize possible
+    # issues during the run
     #
     $installer | Add-Member -membertype ScriptMethod -name 'exception' -value {
         param([string]$message, [string[]]$args);
-        $Error.clear();
+        [array]$exceptions = $this.getProperty('exception_messages');
-        $this.warn('Calling deprecated function exception. Use throw instead.');
+        if ($exceptions -eq $null) {
-        throw 'Exception: ' + $message;
+            $exceptions = @();
+        }
+        $exceptions += $message;
+        $this.setProperty('exception_messages', $exceptions);
+        write-host 'Fatal:' $message -ForegroundColor red;
+        $this.writeLogFile('fatal', $message);
+    }
+
+    #
+    # Get the current exit code of the script. Return 0 for no errors and 1 for
+    # possible errors, including a summary of what went wrong
+    #
+    $installer | Add-Member -membertype ScriptMethod -name 'getScriptExitCode' -value {
+        [array]$exceptions = $this.getProperty('exception_messages');
+
+        if ($exceptions -eq $null) {
+            return 0;
+        }
+
+        $this.writeLogFile('fatal', '##################################################################');
+        $message = '######## The script encountered several errors during run ########';
+        $this.writeLogFile('fatal', $message);
+        $this.writeLogFile('fatal', '##################################################################');
+        write-host $message -ForegroundColor red;
+        foreach ($err in $exceptions) {
+            write-host 'Fatal:' $err -ForegroundColor red;
+            $this.writeLogFile('fatal', $err);
+        }
+
+        return 1;
     }
 
     #
@@ -247,6 +316,7 @@ function Icinga2AgentModule {
     $installer | Add-Member -membertype ScriptMethod -name 'error' -value {
         param([string] $message, [array] $args);
         Write-Host 'Error:' $message -ForegroundColor red;
+        $this.writeLogFile('error', $message);
     }
 
     #
@@ -255,6 +325,7 @@ function Icinga2AgentModule {
     $installer | Add-Member -membertype ScriptMethod -name 'warn' -value {
         param([string] $message, [array] $args);
         Write-Host 'Warning:' $message -ForegroundColor yellow;
+        $this.writeLogFile('warning', $message);
     }
 
     #
@@ -263,6 +334,7 @@ function Icinga2AgentModule {
     $installer | Add-Member -membertype ScriptMethod -name 'info' -value {
         param([string] $message, [array] $args);
         Write-Host 'Notice:' $message -ForegroundColor green;
+        $this.writeLogFile('info', $message);
     }
 
     #
@@ -273,6 +345,7 @@ function Icinga2AgentModule {
         param([string] $message, [array] $args);
         if ($this.config('debug_mode')) {
             Write-Host 'Debug:' $message -ForegroundColor blue;
+            $this.writeLogFile('debug', $message);
         }
     }
 
@@ -283,8 +356,8 @@ function Icinga2AgentModule {
     $installer | Add-Member -membertype ScriptMethod -name 'init' -value {
         $this.setProperty('initialized', $TRUE);
         # Set the default config dir
-        $this.setProperty('config_dir', $Env:ProgramData + '\icinga2\etc\icinga2\');
+        $this.setProperty('config_dir', (Join-Path -Path $Env:ProgramData -ChildPath 'icinga2\etc\icinga2\'));
-        $this.setProperty('api_dir', $Env:ProgramData + '\icinga2\var\lib\icinga2\api');
+        $this.setProperty('api_dir', (Join-Path -Path $Env:ProgramData -ChildPath 'icinga2\var\lib\icinga2\api'));
         $this.setProperty('icinga_ticket', $this.config('ticket'));
         $this.setProperty('local_hostname', $this.config('agent_name'));
         # Ensure we generate the required configuration content
@@ -383,8 +456,7 @@ function Icinga2AgentModule {
 
         # Load all configured global zones
         [array]$global_zones = $this.config('global_zones');
-        # Add director-global zone as default - always
+        [string]$zones = '';
-        [string]$zones = 'object Zone "director-global" {' + "`n" + ' global = true' + "`n" + '}' + "`n";
 
         # In case no zones are given, simply add director-global
         if ($global_zones -eq $NULL) {
@@ -394,8 +466,7 @@ function Icinga2AgentModule {
 
         # Loop through all given zones and add them to our configuration
         foreach ($zone in $global_zones) {
-            # Ignore possible configured director-global zone, as already present
+            if ($zone -ne '') {
-            if ($zone -ne 'director-global') {
                 $zones = $zones + 'object Zone "' + $zone + '" {' + "`n" + ' global = true' + "`n" + '}' + "`n";
             }
         }
@@ -538,7 +609,7 @@ function Icinga2AgentModule {
     # We could try to install the Agent from a local directory
     #
     $installer | Add-Member -membertype ScriptMethod -name 'isDownloadPathLocal' -value {
-        if (Test-Path ($this.config('download_url'))) {
+        if ($this.config('download_url') -And (Test-Path ($this.config('download_url')))) {
             return $TRUE;
         }
         return $FALSE;
@@ -563,10 +634,10 @@ function Icinga2AgentModule {
                 $client.DownloadFile($url, $this.getInstallerPath());
 
                 if (-Not $this.installerExists()) {
-                    throw 'Unable to locate downloaded Icinga 2 Agent installer file from ' + $url + '. Download destination: ' + $this.getInstallerPath();
+                    $this.exception('Unable to locate downloaded Icinga 2 Agent installer file from ' + $url + '. Download destination: ' + $this.getInstallerPath());
                 }
             } catch {
-                throw 'Unable to download Icinga 2 Agent from ' + $url + '. Please ensure the link does exist and access is possible. Error: ' + $_.Exception.Message;
+                $this.exception('Unable to download Icinga 2 Agent from ' + $url + '. Please ensure the link does exist and access is possible. Error: ' + $_.Exception.Message);
             }
         }
     }
@@ -616,14 +687,19 @@ function Icinga2AgentModule {
     # Returns the full path to our installer package
     #
     $installer | Add-Member -membertype ScriptMethod -name 'getInstallerPath' -value {
+        if (-Not $this.config('download_url') -Or -Not $this.getProperty('install_msi_package')) {
+            return '';
+        }
+        $installerPath = Join-Path -Path $this.config('download_url') -ChildPath $this.getProperty('install_msi_package')
         if ($this.isDownloadPathLocal()) {
-            if (Test-Path ($this.config('download_url') + $this.getProperty('install_msi_package'))) {
+            if (Test-Path $installerPath) {
-                return $this.config('download_url') + $this.getProperty('install_msi_package');
+                return $installerPath;
             } else {
-                throw 'Failed to locate local Icinga 2 Agent installer at ' + $this.config('download_url') + $this.getProperty('install_msi_package');
+                $this.exception('Failed to locate local Icinga 2 Agent installer at ' + $installerPath);
+                return '';
             }
         } else {
-            return $Env:temp + '\' + $this.getProperty('install_msi_package');
+            return (Join-Path -Path $Env:temp -ChildPath $this.getProperty('install_msi_package'));
         }
     }
 
@@ -632,30 +708,57 @@ function Icinga2AgentModule {
     # does exist in first place
     #
     $installer | Add-Member -membertype ScriptMethod -name 'installerExists' -value {
-        if (Test-Path $this.getInstallerPath()) {
+        if ($this.getInstallerPath() -And (Test-Path $this.getInstallerPath())) {
             return $TRUE;
         }
         return $FALSE;
     }
 
+    #
+    # Get all arguments for the Icinga 2 Agent installer package
+    #
+    $installer | Add-Member -membertype ScriptMethod -name 'getIcingaAgentInstallerArguments' -value {
+        # Initialise some basic variables
+        [string]$arguments = '';
+        [string]$installerLocation = '';
+
+        # By default, install the Icinga 2 Agent again in the pre-installed directory
+        # before the update. Will only apply during updates / downgrades of the Agent
+        if ($this.getProperty('cur_install_dir')) {
+            $installerLocation = [string]::Format(' INSTALL_ROOT="{0}"', $this.getProperty('cur_install_dir'));
+        }
+
+        # However, if we specified a custom directory over the argument, always use that
+        # one as installer target directory
+        if ($this.config('agent_install_directory')) {
+            $installerLocation = [string]::Format(' INSTALL_ROOT="{0}"', $this.config('agent_install_directory'));
+            $this.setProperty('cur_install_dir', $this.config('agent_install_directory'));
+        }
+
+        $arguments += $installerLocation;
+
+        return $arguments;
+    }
+
     #
     # Install the Icinga 2 agent from the provided installation package
     #
     $installer | Add-Member -membertype ScriptMethod -name 'installAgent' -value {
         $this.downloadInstaller();
         if (-Not $this.installerExists()) {
-            throw 'Failed to setup Icinga 2 Agent. Installer package not found.';
+            $this.exception('Failed to setup Icinga 2 Agent. Installer package not found.');
+            return;
         }
         $this.verifyInstallerChecksumAndThrowException();
-        $this.info('Installing Icinga 2 Agent');
+        $this.info('Installing Icinga 2 Agent...');
 
         # Start the installer process
-        $result = $this.startProcess('MsiExec.exe', $TRUE, '/quiet /i "' + $this.getInstallerPath() + '"');
+        $result = $this.startProcess('MsiExec.exe', $TRUE, [string]::Format('/quiet /i "{0}" {1}', $this.getInstallerPath(), $this.getIcingaAgentInstallerArguments()));
 
         # Exit Code 0 means the Agent was installed successfully
         # Otherwise we require to throw an error
         if ($result.Get_Item('exitcode') -ne 0) {
-            $this.error('Failed to install Icinga 2 Agent. ' + $result.Get_Item('message'));
+            $this.exception('Failed to install Icinga 2 Agent. ' + $result.Get_Item('message'));
         } else {
             $this.info('Icinga 2 Agent installed.');
         }
@@ -670,11 +773,13 @@ function Icinga2AgentModule {
     $installer | Add-Member -membertype ScriptMethod -name 'updateAgent' -value {
         $this.downloadInstaller();
         if (-Not $this.installerExists()) {
-            throw 'Failed to update Icinga 2 Agent. Installer package not found.';
+            $this.exception('Failed to update Icinga 2 Agent. Installer package not found.');
+            return;
         }
         $this.verifyInstallerChecksumAndThrowException()
         if (-Not $this.getProperty('uninstall_id')) {
-            throw 'Failed to update Icinga 2 Agent. Uninstaller is not specified.';
+            $this.exception('Failed to update Icinga 2 Agent. Uninstaller is not specified.');
+            return;
         }
 
         $this.info('Removing previous Icinga 2 Agent version...');
@@ -684,24 +789,23 @@ function Icinga2AgentModule {
         # Exit Code 0 means the Agent was removed successfully
         # Otherwise we require to throw an error
         if ($result.Get_Item('exitcode') -ne 0) {
-            $this.error('Failed to remove Icinga 2 Agent. ' + $result.Get_Item('message'));
+            $this.exception('Failed to remove Icinga 2 Agent. ' + $result.Get_Item('message'));
         } else {
             $this.info('Icinga 2 Agent successfully removed.');
         }
 
         $this.info('Installing new Icinga 2 Agent version...');
         # Start the installer process
-        $result = $this.startProcess('MsiExec.exe', $TRUE, '/quiet /i "' + $this.getInstallerPath() + '"');
+        $result = $this.startProcess('MsiExec.exe', $TRUE, [string]::Format('/quiet /i "{0}" {1}', $this.getInstallerPath(), $this.getIcingaAgentInstallerArguments()));
 
         # Exit Code 0 means the Agent was removed successfully
         # Otherwise we require to throw an error
         if ($result.Get_Item('exitcode') -ne 0) {
-            $this.error('Failed to install new Icinga 2 Agent. ' + $result.Get_Item('message'));
+            $this.exception('Failed to install new Icinga 2 Agent. ' + $result.Get_Item('message'));
         } else {
             $this.info('Icinga 2 Agent successfully updated.');
         }
 
-        $this.setProperty('cur_install_dir', $this.getProperty('def_install_dir'));
         $this.setProperty('require_restart', 'true');
     }
 
@@ -712,7 +816,6 @@ function Icinga2AgentModule {
     #
     $installer | Add-Member -membertype ScriptMethod -name 'isAgentInstalled' -value {
         [string]$architecture = '';
-        [string]$defaultInstallDir = ${Env:ProgramFiles} + "\ICINGA2";
         if ([IntPtr]::Size -eq 4) {
             $architecture = "x86";
             $regPath = 'HKLM:\Software\Microsoft\Windows\CurrentVersion\Uninstall\*';
@@ -738,7 +841,6 @@ function Icinga2AgentModule {
         if ($localData.UninstallString) {
             $this.setProperty('uninstall_id', $localData.UninstallString.Replace("MsiExec.exe ", ""));
         }
-        $this.setProperty('def_install_dir', $defaultInstallDir);
         $this.setProperty('cur_install_dir', $localData.InstallLocation);
         $this.setProperty('agent_version', $localData.DisplayVersion);
         $this.setProperty('install_msi_package', 'Icinga2-v' + $this.config('agent_version') + '-' + $architecture + '.msi');
@@ -748,6 +850,8 @@ function Icinga2AgentModule {
             return $TRUE;
         } else {
             $this.warn('Icinga 2 Agent does not seem to be installed on the system');
+            # Set Default value for install dir
+            $this.setProperty('cur_install_dir', (Join-Path $Env:ProgramFiles -ChildPath 'ICINGA2'));
         }
         return $FALSE;
     }
@@ -805,7 +909,7 @@ function Icinga2AgentModule {
     $installer | Add-Member -membertype ScriptMethod -name 'getNSClientDefaultExecutablePath' -value {
 
         if ($this.config('nsclient_directory')) {
-            return $this.config('nsclient_directory') + '\nscp.exe';
+            return (Join-Path -Path $this.config('nsclient_directory') -ChildPath 'nscp.exe');
         }
 
         if (Test-Path ('C:\Program Files\NSClient++\nscp.exe')) {
@@ -826,7 +930,7 @@ function Icinga2AgentModule {
     # the correct, valid installation path
     #
     $installer | Add-Member -membertype ScriptMethod -name 'getInstallPath' -value {
-        [string]$agentPath = $this.getProperty('def_install_dir');
+        [string]$agentPath = '';
         if ($this.getProperty('cur_install_dir')) {
             $agentPath = $this.getProperty('cur_install_dir');
         }
@@ -842,7 +946,7 @@ function Icinga2AgentModule {
     # use them later again
     #
     $installer | Add-Member -membertype ScriptMethod -name 'backupDefaultConfig' -value {
-        [string]$configFile = $this.getProperty('config_dir') + 'icinga2.conf';
+        [string]$configFile = Join-Path -Path $this.getProperty('config_dir') -ChildPath 'icinga2.conf';
         [string]$configBackupFile = $configFile + 'director.bak';
 
         # Check if a config and backup file already exists
@@ -862,7 +966,7 @@ function Icinga2AgentModule {
     #
     $installer | Add-Member -membertype ScriptMethod -name 'cleanupAgentInstaller' -value {
         if (-Not ($this.isDownloadPathLocal())) {
-            if (Test-Path $this.getInstallerPath()) {
+            if ($this.getInstallerPath() -And (Test-Path $this.getInstallerPath())) {
                 $this.info('Removing downloaded Icinga 2 Agent installer');
                 Remove-Item $this.getInstallerPath() | out-null;
             }
@@ -1106,15 +1210,27 @@ function Icinga2AgentModule {
             }
 
             [string]$icingaNewConfig =
-'/** Icinga 2 Config - proposed by Icinga 2 PowerShell Module */
+'/**
+ * Icinga 2 Config - Proposed by Icinga 2 PowerShell Module
+ */
+
+/* Define our includes to run the agent properly. */
 include "constants.conf"
 include <itl>
 include <plugins>
 include <nscp>
 include <windows-plugins>
 
+/* Define our block required to enable or disable Icinga 2 debug log
+ * Enable or disable it by using the PowerShell Module with
+ * argument -IcingaEnableDebugLog or by switching
+ * PowerShellIcinga2EnableDebug to true or false manually.
+ * true: Debug log is active
+ * false: Debug log is deactivated
+ * IMPORTANT: ";" after true or false has to remain to allow the
+ *            PowerShell Module to switch this feature on or off.
+ */
 const PowerShellIcinga2EnableDebug = false;
-
 if (PowerShellIcinga2EnableDebug) {
   object FileLogger "debug-file" {
     severity = "debug"
@@ -1122,26 +1238,49 @@ if (PowerShellIcinga2EnableDebug) {
   }
 }
 
+/* Try to define a constant for our NSClient++ installation
+ * IMPORTANT: If the NSClient++ is installed newly to the system, the
+ * Icinga Service has to be restarted in order to set this variable
+ * correctly. If the NSClient++ is installed over the PowerShell Module,
+ * the Icinga 2 Service is restarted automaticly.
+ */
 if (!globals.contains("NscpPath")) {
   NscpPath = dirname(msi_get_component_path("{5C45463A-4AE9-4325-96DB-6E239C034F93}"))
 }
+
+/* Enable our default main logger feature to write log output. */
 object FileLogger "main-log" {
   severity = "information"
   path = LocalStateDir + "/log/icinga2/icinga2.log"
 }
 
+/* All informations required to correctly connect to our parent Icinga 2 nodes. */
 object Endpoint "' + $this.getProperty('local_hostname') + '" {}
 ' + $this.getProperty('endpoint_objects') + '
+/* Define the zone and its containing endpoints we should communicate with. */
 object Zone "' + $this.config('parent_zone') + '" {
   endpoints = [ ' + $this.getProperty('endpoint_nodes') +' ]
 }
 
+/* All of our global zones, check commands and other configuration are synced into.
+ * Director global zone must be defined in case the Icinga Director is beeing used.
+ * Default value for this is "director-global".
+ * All additional zones can be configured with -GlobalZones argument.
+ * IMPORTANT: If -GlobalZones argument is used, the Icinga Director global zones has
+ *            to be defined as well within the argument array.
+ */
 ' + $this.getProperty('global_zones') + '
+/* Define a zone for our current agent and set our parent zone for proper communication. */
 object Zone "' + $this.getProperty('local_hostname') + '" {
   parent = "' + $this.config('parent_zone') + '"
   endpoints = [ "' + $this.getProperty('local_hostname') + '" ]
 }
 
+/* Configure all settings we require for our API listener to properly work.
+ * This will include the certificates, if we accept configurations which
+ * can be changed with argument -AcceptConfig and the bind informations.
+ * The bind_port can be modified with argument -AgentListenPort.
+ */
 object ApiListener "api" {
   cert_path = SysconfDir + "/icinga2/pki/' + $this.getProperty('local_hostname') + '.crt"
   key_path = SysconfDir + "/icinga2/pki/' + $this.getProperty('local_hostname') + '.key"
@@ -1201,7 +1340,7 @@ object ApiListener "api" {
     # Return the path to the Icinga 2 config file
     #
     $installer | Add-Member -membertype ScriptMethod -name 'getIcingaConfigFile' -value {
-        return ($this.getProperty('config_dir') + 'icinga2.conf');
+        return (Join-Path -Path $this.getProperty('config_dir') -ChildPath 'icinga2.conf');
     }
 
     #
@@ -1260,8 +1399,8 @@ object ApiListener "api" {
     $installer | Add-Member -membertype ScriptMethod -name 'generateCertificates' -value {
 
         if ($this.getProperty('local_hostname') -And $this.config('ca_server') -And $this.getProperty('icinga_ticket')) {
-            [string]$icingaPkiDir = $this.getProperty('config_dir') + 'pki\';
+            [string]$icingaPkiDir = Join-Path -Path $this.getProperty('config_dir') -ChildPath 'pki\';
-            [string]$icingaBinary = $this.getInstallPath() + '\sbin\icinga2.exe';
+            [string]$icingaBinary = Join-Path -Path $this.getInstallPath() -ChildPath 'sbin\icinga2.exe';
             [string]$agentName = $this.getProperty('local_hostname');
 
             if (-Not (Test-Path $icingaBinary)) {
@@ -1335,12 +1474,12 @@ object ApiListener "api" {
     # Agent. If not, return FALSE
     #
     $installer | Add-Member -membertype ScriptMethod -name 'hasCertificates' -value {
-        [string]$icingaPkiDir = $this.getProperty('config_dir') + 'pki\';
+        [string]$icingaPkiDir = Join-Path -Path $this.getProperty('config_dir') -ChildPath 'pki';
         [string]$agentName = $this.getProperty('local_hostname');
         if (
-            ((Test-Path ($icingaPkiDir + $agentName + '.key')) `
+            ((Test-Path ((Join-Path -Path $icingaPkiDir -ChildPath $agentName) + '.key'))) `
-            -And (Test-Path ($icingaPkiDir + $agentName + '.crt')) `
+            -And (Test-Path ((Join-Path -Path $icingaPkiDir -ChildPath $agentName) + '.crt')) `
-            -And (Test-Path ($icingaPkiDir + 'ca.crt')))
+            -And (Test-Path (Join-Path -Path $icingaPkiDir -ChildPath 'ca.crt'))
         ) {
             return $TRUE;
         }
@@ -1386,11 +1525,26 @@ object ApiListener "api" {
     # Have we specified a version to install the Agent?
     #
     $installer | Add-Member -membertype ScriptMethod -name 'canInstallAgent' -value {
-        if (-Not $this.config('agent_version')) {
+        if ($this.config('download_url') -And $this.config('agent_version')) {
+            return $TRUE;
+        }
+
+        if (-Not $this.config('download_url') -And -Not $this.config('agent_version')) {
+            $this.warn('Icinga 2 Agent will not be installed. Arguments -DownloadUrl and -InstallAgentVersion both not defined.');
             return $FALSE;
         }
 
-        return $TRUE;
+        if (-Not $this.config('agent_version')) {
+            $this.warn('Icinga 2 Agent will not be installed. Argument -InstallAgentVersion is not defined.');
+            return $FALSE;
+        }
+
+        if (-Not $this.config('download_url')) {
+            $this.warn('Icinga 2 Agent will not be installed. Argument -DownloadUrl is not defined.');
+            return $FALSE;
+        }
+
+        return $FALSE;
     }
 
     #
@@ -1418,7 +1572,7 @@ object ApiListener "api" {
         if (-Not $this.config('parent_zone') -And $checkInternal) {
             throw 'Parent Zone not defined. Please specify it with -ParentZone <name>';
         }
-        $icingaBinary = $this.getInstallPath() + '\sbin\icinga2.exe';
+        $icingaBinary = Join-Path -Path $this.getInstallPath() -ChildPath 'sbin\icinga2.exe';
 
         if (Test-Path $icingaBinary) {
             $result = $this.startProcess($icingaBinary, $FALSE, 'daemon -C');
@@ -1782,7 +1936,7 @@ object ApiListener "api" {
     #
     $installer | Add-Member -membertype ScriptMethod -name 'writeHostAPIKeyToDisk' -value {
         if (Test-Path ($this.getProperty('config_dir'))) {
-            [string]$apiFile = $this.getProperty('config_dir') + 'icingadirector.token';
+            [string]$apiFile = Join-Path -Path $this.getProperty('config_dir') -ChildPath 'icingadirector.token';
             $this.info('Writing host API-Key "' + $this.getProperty('director_host_token') + '" to "' + $apiFile + '"');
             [System.IO.File]::WriteAllText($apiFile, $this.getProperty('director_host_token'));
         }
@@ -1792,7 +1946,7 @@ object ApiListener "api" {
     # Read Host API-Key from disk for usage
     #
     $installer | Add-Member -membertype ScriptMethod -name 'readHostAPIKeyFromDisk' -value {
-        [string]$apiFile = $this.getProperty('config_dir') + 'icingadirector.token';
+        [string]$apiFile = Join-Path -Path $this.getProperty('config_dir') -ChildPath 'icingadirector.token';
         if (Test-Path ($apiFile)) {
             [string]$hostToken = [System.IO.File]::ReadAllText($apiFile);
             $this.setProperty('director_host_token', $hostToken);
@@ -1870,6 +2024,46 @@ object ApiListener "api" {
         return $TRUE;
     }
 
+    #
+    # This function will convert a [hashtable] or [array] object to string
+    # with function ConvertTo-Json for argument -DirectorHostObject.
+    # It will however only process those if the PowerShell Version is 3
+    # and above, because Version 2 is not providing the required
+    # functionality. In that case the module will throw an exception
+    #
+    $installer | Add-Member -membertype ScriptMethod -name 'convertDirectorHostObjectArgument' -value {
+
+        # First add the value to an object we can work with
+        [System.Object]$json = $this.config('director_host_object');
+
+        # Prevent processing of empty data
+        if ($json -eq $null -Or $json -eq '') {
+            return;
+        }
+
+        # In case the argument is already a string -> nothing to do
+        if ($json.GetType() -eq [string]) {
+            # Do nothing
+            return;
+        } elseif ($json.GetType() -eq [hashtable] -Or $json.GetType() -eq [array]) {
+            # Check which PowerShell Version we are using and throw an error in case our Version does not support the argument
+            if ($PSVersionTable.PSVersion.Major -lt 3) {
+                [string]$errorMessage = 'You are trying to pass an object of type [hashtable] or [array] for argument "-DirectorHostObject", but are using ' +
+                                        'PowerShell Version 2 or lower. Passing hashtables through this argument is possible, but it requires to be ' +
+                                        'converted with function ConvertTo-Json, which is available on PowerShell Version 3 and above only. ' +
+                                        'You can still process JSON-Values with this module, even on PowerShell Version 2, but you will have to pass the ' +
+                                        'JSON as string instead of an object. This module will now exit with an error code. For further details, please ' +
+                                        'read the documentation for the "-DirectorHostObject" argument. ' +
+                                        'Documentation: https://github.com/Icinga/icinga2-powershell-module/blob/master/doc/10-Basic-Arguments.md';
+                $this.exception($errorMessage);
+                throw 'PowerShell Version exception.';
+            }
+
+            # If our PowerShell Version is supporting the function, convert it to a valid string
+            $this.overrideConfig('director_host_object', (ConvertTo-Json -Compress $json));
+        }
+    }
+
     #
     # This function will fetch all arguments configured inside the Icinga Director
     # to allow an entire auto configuration of the Icinga 2 Agent
@@ -1995,7 +2189,7 @@ object ApiListener "api" {
                 # Exit Code 0 means the NSClient was installed successfully
                 # Otherwise we require to throw an error
                 if ($result.Get_Item('exitcode') -ne 0) {
-                    $this.error('Failed to install NSClient++. ' + $result.Get_Item('message'));
+                    $this.exception('Failed to install NSClient++. ' + $result.Get_Item('message'));
                 } else {
                     $this.info('NSClient++ successfully installed.');
                 }
@@ -2034,13 +2228,13 @@ object ApiListener "api" {
 
             $this.info('Trying to download NSClient++ from ' + $this.config('nsclient_installer_path'));
             [System.Object]$client = New-Object System.Net.WebClient;
-            $client.DownloadFile($this.config('nsclient_installer_path'), $Env:temp + '\NSCP.msi');
+            $client.DownloadFile($this.config('nsclient_installer_path'), (Join-Path -Path $Env:temp -ChildPath 'NSCP.msi'));
 
-            return $Env:temp + '\NSCP.msi';
+            return (Join-Path -Path $Env:temp -ChildPath 'NSCP.msi');
         } else {
             # Icinga is shipping a NSClient Version after installation
             # Install this version if defined
-            return $this.getInstallPath() + '\sbin\NSCP.msi';
+            return (Join-Path -Path $this.getInstallPath() -ChildPath 'sbin\NSCP.msi');
         }
 
         return '';
@@ -2141,8 +2335,12 @@ object ApiListener "api" {
     # Deprecated function
     #
     $installer | Add-Member -membertype ScriptMethod -name 'installIcinga2Agent' -value {
-        $this.warn('The function "installIcinga2Agent" is deprecated and will be removed soon. Please use "installMonitoringComponents" instead.')
+        $this.warn('The function "installIcinga2Agent" is deprecated and will be removed soon. Please use "install" instead.')
-        return $this.installMonitoringComponents();
+        return $this.install();
+    }
+    $installer | Add-Member -membertype ScriptMethod -name 'installMonitoringComponents' -value {
+        $this.warn('The function "installMonitoringComponents" is deprecated and will be removed soon. Please use "install" instead.')
+        return $this.install();
     }
 
     #
@@ -2152,14 +2350,18 @@ object ApiListener "api" {
     # including download and update if
     # specified. Returnd 0 or 1 as exit code
     #
-    $installer | Add-Member -membertype ScriptMethod -name 'installMonitoringComponents' -value {
+    $installer | Add-Member -membertype ScriptMethod -name 'install' -value {
         try {
             if (-Not $this.isAdmin()) {
                 return 1;
             }
 
+            # Write an output to the logfile only, ensuring we always get a proper 'start entry' for the user
+            $this.info('Started script run...');
             # Get the current API-Version from the Icinga Director
             $this.getIcingaDirectorVersion();
+            # Convert our DirectorHostObject argument from Object to String if required
+            $this.convertDirectorHostObjectArgument();
             # Read arguments for auto config from the Icinga Director
             # At first only with our public key for global config attributes
             $this.fetchArgumentsFromIcingaDirector($TRUE);
@@ -2227,17 +2429,30 @@ object ApiListener "api" {
             # We modify the service user at the very last to ensure
             # the user we defined for logging in is valid
             $this.modifyIcingaServiceUser();
-            return 0;
+            return $this.getScriptExitCode();
         } catch {
             $this.printLastException();
+            [void]$this.getScriptExitCode();
             return 1;
         }
     }
 
     #
-    # Removes the Icinga 2 Agent from the system
+    # Deprecated function
     #
     $installer | Add-Member -membertype ScriptMethod -name 'uninstallIcinga2Agent' -value {
+        $this.warn('The function "uninstallIcinga2Agent" is deprecated and will be removed soon. Please use "uninstall" instead.')
+        return $this.uninstall();
+    }
+    $installer | Add-Member -membertype ScriptMethod -name 'uninstallMonitoringComponents' -value {
+        $this.warn('The function "uninstallMonitoringComponents" is deprecated and will be removed soon. Please use "uninstall" instead.')
+        return $this.uninstall();
+    }
+
+    #
+    # Removes the Icinga 2 Agent from the system
+    #
+    $installer | Add-Member -membertype ScriptMethod -name 'uninstall' -value {
         $this.info('Trying to locate Icinga 2 Agent...');
 
         if ($this.isAgentInstalled()) {
@@ -2254,22 +2469,56 @@ object ApiListener "api" {
 
         if ($this.config('full_uninstallation')) {
             $this.info('Flushing Icinga 2 program data directory...');
-            if (Test-Path ($Env:ProgramData + '\icinga2\')) {
+            if (Test-Path ((Join-Path -Path $Env:ProgramData -ChildPath 'icinga2'))) {
                 try {
                     [System.Object]$folder = New-Object -ComObject Scripting.FileSystemObject;
-                    $folder.DeleteFolder($Env:ProgramData + '\icinga2');
+                    [void]$folder.DeleteFolder((Join-Path -Path $Env:ProgramData -ChildPath 'icinga2'));
                     $this.info('Remaining Icinga 2 configuration successfully removed.');
                 } catch {
-                    $this.error('Failed to delete Icinga 2 Program Data Directory: ' + $_.Exception.Message);
+                    $this.exception('Failed to delete Icinga 2 Program Data Directory: ' + $_.Exception.Message);
-                    return 1;
                 }
             } else {
                 $this.warn('Icinga 2 Agent program directory not present.');
             }
         }
 
-        return 0;
+        if ($this.config('remove_nsclient')) {
+            $this.info('Trying to remove installed NSClient++...');
+
+            $nsclient = Get-WmiObject -Class Win32_Product |
+                Where-Object {
+                    $_.Name -match 'NSClient*';
+                }
+
+            if ($nsclient -ne $null) {
+                $this.info('Removing installed NSClient++...');
+                [void]$nsclient.Uninstall();
+                $this.info('NSClient++ has been successfully removed.');
+            } else {
+                $this.warn('NSClient++ could not be located on the system. Nothing to remove.');
+            }
+        }
+
+        return $this.getScriptExitCode();
     }
 
+    # Make the installation / uninstallation of the script easier and shorter
+    [int]$installerExitCode = 0;
+    [int]$uninstallerExitCode = 0;
+    # If flag RunUninstaller is set, do the uninstallation of the components
+    if ($RunUninstaller) {
+        $uninstallerExitCode = $installer.uninstall();
+    }
+    # If flag RunInstaller is set, do the installation of the components
+    if ($RunInstaller) {
+        $installerExitCode = $installer.install();
+    }
+    if ($RunInstaller -Or $RunUninstaller) {
+        if ($installerExitCode -ne 0 -Or $uninstallerExitCode -ne 0) {
+            return 1;
+        }
+    }
+
+    # Otherwise handle everything as before
     return $installer;
 }