Fix health API returning empty results for processor, storage and mempool (librenms#19953)

* Fix health API returning empty results for processor, storage and mempool

* Fix code quality issues

* Address review comments - removing soft delete reference for mempool

Author: abhishekambastha

doc/API/Devices.md

@@ -250,6 +250,11 @@ Route: `/api/v0/devices/:hostname/health(/:type)(/:sensor_id)`
 - type (optional) is health type / sensor class
 - sensor_id (optional) is the sensor id to retrieve specific information.
 
+`type` may be a sensor class (e.g. `device_voltage`) or one of the special
+classes `device_processor`, `device_storage` and `device_mempool`, which are
+stored in their own tables rather than the `sensors` table. The `device_`
+prefix is optional, so `processor` and `device_processor` are equivalent.
+
 Input:
 
   -
@@ -348,6 +353,28 @@ Output:
 }
 ```
 
+Example (processor list):
+
+```curl
+curl -H 'X-Auth-Token: YOURAPITOKENHERE' https://foo.example/api/v0/devices/localhost/health/processor
+```
+
+Output:
+
+```
+{
+    "status": "ok",
+    "message": "",
+    "count": 1,
+    "graphs": [
+        {
+            "sensor_id": "1",
+            "desc": "Processor"
+        }
+    ]
+}
+```
+
 ### `list_available_wireless_graphs`
 
 This function allows to do three things:

includes/html/api_functions.inc.php

@@ -30,6 +30,7 @@
 use App\Models\Ipv6Network;
 use App\Models\Link;
 use App\Models\Location;
+use App\Models\Mempool;
 use App\Models\MplsSap;
 use App\Models\MplsService;
 use App\Models\OspfPort;
@@ -43,8 +44,10 @@
 use App\Models\PortSecurity;
 use App\Models\PortsFdb;
 use App\Models\PortsNac;
+use App\Models\Processor;
 use App\Models\Sensor;
 use App\Models\ServiceTemplate;
+use App\Models\Storage;
 use App\Models\UserPref;
 use App\Models\Vlan;
 use App\Models\Vrf;
@@ -1045,8 +1048,28 @@ function list_available_health_graphs(Illuminate\Http\Request $request)
         $sensor_id = $request->route('sensor_id');
         $graphs = [];
 
+        // processors, storage and mempools are not stored in the `sensors` table,
+        // so they need to be looked up via their own models.
+        $health_models = [
+            'processor' => ['model' => Processor::class, 'id' => 'processor_id', 'descr' => 'processor_descr'],
+            'storage' => ['model' => Storage::class, 'id' => 'storage_id', 'descr' => 'storage_descr'],
+            'mempool' => ['model' => Mempool::class, 'id' => 'mempool_id', 'descr' => 'mempool_descr'],
+        ];
+
         if (isset($type)) {
-            if (isset($sensor_id)) {
+            if (isset($health_models[$type])) {
+                $health = $health_models[$type];
+                if (isset($sensor_id)) {
+                    $graphs = $health['model']::where($health['id'], $sensor_id)->get()->toArray();
+                } else {
+                    foreach ($health['model']::where('device_id', $device_id)->get() as $graph) {
+                        $graphs[] = [
+                            'sensor_id' => $graph->{$health['id']},
+                            'desc' => $graph->{$health['descr']},
+                        ];
+                    }
+                }
+            } elseif (isset($sensor_id)) {
                 $graphs = dbFetchRows('SELECT * FROM `sensors` WHERE `sensor_id` = ?', [$sensor_id]);
             } else {
                 foreach (dbFetchRows('SELECT `sensor_id`, `sensor_descr` FROM `sensors` WHERE `device_id` = ? AND `sensor_class` = ? AND `sensor_deleted` = 0', [$device_id, $type]) as $graph) {