New python service for poller, discovery + more (#8455)

Currently has a file handle leak (and will eventually run out of handles) related to the self update process.

Either need to fix that or rip out self-update and leave that up to cron or something.


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discovery.php

@@ -125,7 +125,7 @@ if (!empty($config['distributed_poller_group'])) {
 
 global $device;
 foreach (dbFetch("SELECT * FROM `devices` WHERE disabled = 0 AND snmp_disable = 0 $where ORDER BY device_id DESC", $sqlparams) as $device) {
-    discover_device($device, $options);
+    $discovered_devices += discover_device($device, $options);
 }
 
 $end      = microtime(true);
@@ -152,3 +152,8 @@ if (!isset($options['q'])) {
 }
 
 logfile($string);
+
+if ($discovered_devices == 0) {
+    # No discoverable devices, either down or disabled
+    exit(5);
+}