add ts3_up metric to signal failed query connection

src/help.php

@@ -1,6 +1,7 @@
 <?php
 
 $help_texts = [
+    'up'                                        => 'Query connection; 1 = success, 0 = fail',
     'virtualserver_clientsonline'               => 'Clients online (e.g. Users)',
     'virtualserver_queryclientsonline'          => 'Query clients online (e.g. this exporter)',
     'virtualserver_total_packetloss_speech'     => 'Average packet loss',

src/metrics.php

@@ -3,15 +3,6 @@ require_once('../vendor/autoload.php');
 require_once('help.php'); // provides $help_texts
 
 
-$host = 'localhost';
-$port = 10011;
-$user = rawurlencode('serveradmin');
-$password = rawurlencode('4NReP1Wf');
-$ssh = TRUE;
-
-$uri = 'serverquery://'.$user.':'.$password.'@'.$host.':'.$port.'/';
-
-
 // initialize the Prometheus registry
 $registry = new \Prometheus\CollectorRegistry(new \Prometheus\Storage\InMemory());
 $namespace = 'ts3';
@@ -20,11 +11,25 @@ $virtualserver_label_keys = [
     'virtualserver_port',
     'virtualserver_unique_identifier'
 ];
-$totals = [
-    'virtualserver_uptime'
-];
+
+// set ${namespace}_up for exporter status
+$up = $registry->getOrRegisterGauge(
+    $namespace,
+    'up',
+    $help_texts['up'],
+    []
+);
+$up->set(1, []);
 
 
+$host = '192.168.178.55';
+$port = 10011;
+$user = rawurlencode('serveradmin');
+$password = rawurlencode('4NReP1Wf');
+
+$uri = 'serverquery://'.$user.':'.$password.'@'.$host.':'.$port.'/';
+
+try {
     // open a connection to the server
     $ts3 = TeamSpeak3::factory($uri);
 
@@ -37,7 +42,6 @@ foreach($ts3->serverList() as $virtualserver) {
 
         // fill $virtualserver_label_values
         foreach($virtualserver_label_keys as $virtualserver_label_key) {
-        $value = $infos[$virtualserver_label_key];
             $virtualserver_label_values[] = $infos[$virtualserver_label_key];
         }
 
@@ -58,9 +62,13 @@ foreach($ts3->serverList() as $virtualserver) {
             }
         }
     }
+} catch (Exception $e) {
+    // something failed, set ${namespace}_up to 0
+    $up->set(0, []);
+}
 
 
-// render all metrics as HTML and output them
+// render all metrics and output them
 $renderer = new \Prometheus\RenderTextFormat();
 $result = $renderer->render($registry->getMetricFamilySamples());