Distributed Poller improved validation (#12269)

LibreNMS/Exceptions/InvalidNameException.php

@@ -0,0 +1,32 @@
+<?php
+/*
+ * InvalidNameException.php
+ *
+ * -Description-
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * @package    LibreNMS
+ * @link       http://librenms.org
+ * @copyright  2020 Tony Murray
+ * @author     Tony Murray <murraytony@gmail.com>
+ */
+
+namespace LibreNMS\Exceptions;
+
+
+class InvalidNameException extends \Exception
+{
+
+}

LibreNMS/ValidationResult.php

@@ -29,6 +29,7 @@ class ValidationResult
     const FAILURE = 0;
     const WARNING = 1;
     const SUCCESS = 2;
+    const INFO = 3;
 
     private $message;
     private $status;
@@ -71,6 +72,16 @@ class ValidationResult
         return new self($message, self::WARNING, $fix);
     }
 
+    /**
+     * Create a new informational Validation result
+     * @param string $message The message to describe this result
+     * @return ValidationResult
+     */
+    public static function info($message)
+    {
+        return new self($message, self::INFO);
+    }
+
     /**
      * Create a new failure Validation result
      * @param string $message The message to describe this result
@@ -173,15 +184,14 @@ class ValidationResult
      */
     public static function getStatusText($status)
     {
-        if ($status === self::SUCCESS) {
+        $table = [
-            return '%gOK%n';
+            self::SUCCESS => '%gOK%n',
-        } elseif ($status === self::WARNING) {
+            self::WARNING => '%YWARN%n',
-            return '%YWARN%n';
+            self::FAILURE => '%RFAIL%n',
-        } elseif ($status === self::FAILURE) {
+            self::INFO => '%CINFO%n',
-            return '%RFAIL%n';
+        ];
-        }
 
-        return 'Unknown';
+        return $table[$status] ?? 'Unknown';
     }
 
     public function getListDescription()

LibreNMS/Validations/DistributedPoller.php

@@ -31,12 +31,18 @@
 
 namespace LibreNMS\Validations;
 
+use App\Models\PollerCluster;
+use Carbon\Carbon;
 use LibreNMS\Config;
 use LibreNMS\Validator;
 
 class DistributedPoller extends BaseValidation
 {
-    protected static $RUN_BY_DEFAULT = false;
+    public function isDefault()
+    {
+        // run by default if distributed polling is enabled
+        return Config::get('distributed_poller');
+    }
 
     /**
      * Validate this module.
@@ -47,11 +53,62 @@ class DistributedPoller extends BaseValidation
     public function validate(Validator $validator)
     {
         if (! Config::get('distributed_poller')) {
-            $validator->fail('You have not enabled distributed_poller');
+            $validator->fail('You have not enabled distributed_poller', 'lnms config:set distributed_poller true');
 
             return;
         }
 
+        if (! Config::get('rrdcached')) {
+            $validator->fail('You have not configured $config[\'rrdcached\']');
+        } elseif (! is_dir(Config::get('rrd_dir'))) {
+            $validator->fail('You have not configured $config[\'rrd_dir\']');
+        } else {
+            Rrd::checkRrdcached($validator);
+        }
+
+        if (PollerCluster::exists()) {
+            if (PollerCluster::isActive()->exists()) {
+                $validator->info('Detected Dispatcher Service');
+                $this->checkDispatcherService($validator);
+                return;
+            }
+
+            $validator->warn('Dispatcher Service has been used in your cluster, but not recently. It may take up to 5 minutes to register.');
+        }
+
+        $validator->info('Detected Python Wrapper');
+        $this->checkPythonWrapper($validator);
+    }
+
+    private function checkDispatcherService(Validator $validator)
+    {
+        $driver = config('cache.default');
+        if ($driver != 'redis') {
+            $validator->warn("Using $driver for distributed locking, you should set CACHE_DRIVER=redis");
+        }
+
+        try {
+            $lock = \Cache::lock('dist_test_validation');
+            $lock->get();
+            $lock->release();
+        } catch (\Exception $e) {
+            $validator->fail('Locking server issue: ' . $e->getMessage());
+        }
+
+        $node = PollerCluster::firstWhere('node_id', config('librenms.node_id'));
+        if (! $node->exists) {
+            $validator->fail('Dispatcher service is enabled on your cluster, but not in use on this node');
+            return;
+        }
+
+        if ($node->last_report->lessThan(Carbon::now()->subSeconds($node->getSettingValue('poller_frequency')))) {
+            $validator->fail('Dispatcher service has not reported stats within the last poller window');
+        }
+
+    }
+
+    private function checkPythonWrapper(Validator $validator)
+    {
         if (! Config::get('distributed_poller_memcached_host')) {
             $validator->fail('You have not configured $config[\'distributed_poller_memcached_host\']');
         } elseif (! Config::get('distributed_poller_memcached_port')) {
@@ -65,13 +122,5 @@ class DistributedPoller extends BaseValidation
                 $validator->ok('Connection to memcached is ok');
             }
         }
-
-        if (! Config::get('rrdcached')) {
-            $validator->fail('You have not configured $config[\'rrdcached\']');
-        } elseif (! is_dir(Config::get('rrd_dir'))) {
-            $validator->fail('You have not configured $config[\'rrd_dir\']');
-        } else {
-            Rrd::checkRrdcached($validator);
-        }
     }
 }

LibreNMS/Validator.php

@@ -218,6 +218,17 @@ class Validator
         $this->result(new ValidationResult($message, ValidationResult::FAILURE, $fix), $group);
     }
 
+    /**
+     * Submit an informational validation result.
+     *
+     * @param string $message
+     * @param string $group manually specify the group, otherwise this will be inferred from the callers class name
+     */
+    public function info($message, $group = null)
+    {
+        $this->result(new ValidationResult($message, ValidationResult::INFO), $group);
+    }
+
     /**
      * Get version_info() array.  This will cache the result and add remote data if requested and not already existing.
      *

app/Models/PollerCluster.php

@@ -25,6 +25,7 @@
 namespace App\Models;
 
 use Illuminate\Database\Eloquent\Model;
+use LibreNMS\Exceptions\InvalidNameException;
 
 class PollerCluster extends Model
 {
@@ -32,6 +33,9 @@ class PollerCluster extends Model
     protected $table = 'poller_cluster';
     protected $primaryKey = 'id';
     protected $fillable = ['poller_name'];
+    protected $casts = [
+        'last_report' => 'datetime',
+    ];
 
     // ---- Accessors/Mutators ----
 
@@ -40,17 +44,45 @@ class PollerCluster extends Model
         $this->attributes['poller_groups'] = is_array($groups) ? implode(',', $groups) : $groups;
     }
 
+    // ---- Scopes ----
+
+    public function scopeIsActive($query)
+    {
+        $default = (int) \LibreNMS\Config::get('service_poller_frequency');
+        $query->where('last_report', '>=', \DB::raw("DATE_SUB(NOW(),INTERVAL COALESCE(`poller_frequency`, $default) SECOND)"));
+    }
+
     // ---- Helpers ----
 
+    /**
+     * Get the value of a setting (falls back to the global value if not set on this node)
+     *
+     * @param string $name
+     * @return mixed
+     * @throws \LibreNMS\Exceptions\InvalidNameException
+     */
+    public function getSettingValue(string $name)
+    {
+        $definition = $this->configDefinition(false);
+
+        foreach ($definition as $entry) {
+            if ($entry['name'] == $name) {
+                return $entry['value'];
+            }
+        }
+
+        throw new InvalidNameException("Poller group setting named \"$name\" is invalid");
+    }
+
     /**
      * Get the frontend config definition for this poller
      *
-     * @param \Illuminate\Support\Collection $groups optionally supply full list of poller groups to avoid fetching multiple times
+     * @param \Illuminate\Support\Collection|bool|null $groups optionally supply full list of poller groups to avoid fetching multiple times
      * @return array[]
      */
     public function configDefinition($groups = null)
     {
-        if (empty($groups)) {
+        if ($groups === null || $groups === true) {
             $groups = PollerGroup::list();
         }
 

config/librenms.php

@@ -43,4 +43,14 @@ return [
 
     'install' => env('INSTALL', false),
 
+    /*
+    |--------------------------------------------------------------------------
+    | NODE ID
+    |--------------------------------------------------------------------------
+    |
+    | Unique value to identify this node. Primarily used for distributed polling.
+    */
+
+    'node_id' => env('NODE_ID'),
+
 ];