I added a bunch of checks to make sure no null values get passed to telegraf.

I'm sure there is a better way to do this, but I am not a php developer and it's Sunday.

Issue: https://github.com/VictorRobellini/pfSense-Dashboard/issues/39
Reporter: https://github.com/xppx99

Thanks for the heads up xppx99

plugins/telegraf_pfifgw.php

@@ -19,38 +19,49 @@ foreach ($iflist as $ifname => $friendly) {
     $realif = get_real_interface($ifname);
     $mac = get_interface_mac($realif);
 
-	if (!isset($ip4addr)){
+    if (!isset($ifinfo)) {
-		$ip4addr = "Unassigned";
+        $ifinfo = "Unavailable";
     }
-	if (!isset($ip4subnet)){
+    if (strtolower($ifstatus) == "up") {
-		$ip4subnet = "Unassigned";
-	}
-	if (!isset($ip6addr)){
-		$ip6addr = "Unassigned";
-	}
-	if (!isset($ip6subnet)){
-		$ip6subnet = "Unassigned";
-	}
-	if (!isset($mac)){
-		$mac = "Unavailable";
-	}
-	if (strtolower($ifstatus) == "up"){
         $ifstatus = 1;
     }
-	if (strtolower($ifstatus) == "active"){
+    if (strtolower($ifstatus) == "active") {
         $ifstatus = 1;
     }
-	if (strtolower($ifstatus) == "no carrier"){
+    if (strtolower($ifstatus) == "no carrier") {
         $ifstatus = 0;
     }
-	if (strtolower($ifstatus) == "down"){
+    if (strtolower($ifstatus) == "down") {
         $ifstatus = 0;
     }
-	if (!isset($ifstatus)){
+    if (!isset($ifstatus)) {
         $ifstatus = 2;
     }
+    if (!isset($ifconf)) {
+        $ifconf = "Unassigned";
+    }
+    if (!isset($ip4addr)) {
+        $ip4addr = "Unassigned";
+    }
+    if (!isset($ip4subnet)) {
+        $ip4subnet = "0";
+    }
+    if (!isset($ip6addr)) {
+        $ip6addr = "Unassigned";
+    }
+    if (!isset($ip6subnet)) {
+        $ip6subnet = "Unassigned";
+    }
+    if (!isset($realif)) {
+        $realif = "Unassigned";
+    }
+    if (!isset($mac)) {
+        $mac = "Unavailable";
+    }
 
-	printf("interface,host=%s,name=%s,ip4_address=%s,ip4_subnet=%s,ip6_address=%s,ip6_subnet=%s,mac_address=%s,friendlyname=%s,source=%s status=%s\n",
+
+    printf(
+        "interface,host=%s,name=%s,ip4_address=%s,ip4_subnet=%s,ip6_address=%s,ip6_subnet=%s,mac_address=%s,friendlyname=%s,source=%s status=%s\n",
         $host,
         $realif,
         $ip4addr,
@@ -70,7 +81,7 @@ $gw_statuses = return_gateways_status(true);
 
 $debug = false;
 
-if($debug){
+if ($debug) {
     print_r($gw_array);
     print_r($gw_statuses);
 }
@@ -94,19 +105,45 @@ foreach ($gw_array as $gw => $gateway) {
     $gwdescr = $gateway["descr"];
     $defaultgw = $gateway['isdefaultgw'];
 
+    if (!isset($monitor)) {
+        $monitor = "Unavailable";
+    }
+    if (!isset($source)) {
+        $source = "Unavailable";
+    }
+    if (!isset($delay)) {
+        $delay = "0";
+    }
+    if (!isset($stddev)) {
+        $stddev = "0";
+    }
+    if (!isset($loss)) {
+        $loss = "0";
+    }
+    if (!isset($status)) {
+        $status = "Unavailable";
+    }
+    if (!isset($interface)) {
+        $interface = "Unassigned";
+    }
+    if (!isset($friendlyname)) {
+        $friendlyname = "Unassigned";
+    }
+    if (!isset($friendlyifdescr)) {
+        $friendlyifdescr = "Unassigned";
+    }
+    if (!isset($gwdescr)) {
+        $gwdescr = "Unassigned";
+    }
+
     if (isset($gateway['isdefaultgw'])) {
         $defaultgw = "1";
     } else {
         $defaultgw = "0";
     }
 
-	if ($gw_statuses[$gw]) {
     if (isset($gateway['monitor_disable'])) {
         $monitor = "Unmonitored";
-			$delay = "Pending";
-			$stdev = "Pending";
-			$loss = "Pending";
-		}
     }
 
     // Some earlier versions of pfSense do not return substatus
@@ -116,10 +153,11 @@ foreach ($gw_array as $gw => $gateway) {
         $substatus = "N/A";
     }
 
-	printf("gateways,host=%s,interface=%s,gateway_name=%s monitor=\"%s\",source=\"%s\",defaultgw=%s,gwdescr=\"%s\",delay=%s,stddev=%s,loss=%s,status=\"%s\",substatus=\"%s\"\n",
+    printf(
+        "gateways,host=%s,interface=%s,gateway_name=%s monitor=\"%s\",source=\"%s\",defaultgw=%s,gwdescr=\"%s\",delay=%s,stddev=%s,loss=%s,status=\"%s\",substatus=\"%s\"\n",
         $host,
         $interface,
-		$name,//name is required as it is possible to have 2 gateways on 1 interface.  i.e. WAN_DHCP and WAN_DHCP6
+        $name, //name is required as it is possible to have 2 gateways on 1 interface.  i.e. WAN_DHCP and WAN_DHCP6
         $monitor,
         $source,
         $defaultgw,