Merge pull request #567 from Icinga/handle-redis-errors-gracefully

Handle redis errors gracefully

application/controllers/HostgroupController.php

@@ -59,7 +59,7 @@ class HostgroupController extends Controller
         $paginationControl = $this->createPaginationControl($hosts);
         $viewModeSwitcher = $this->createViewModeSwitcher($paginationControl, $limitControl);
 
-        $hostList = (new HostList($hosts))
+        $hostList = (new HostList($hosts->execute()))
             ->setViewMode($viewModeSwitcher->getViewMode());
 
         yield $this->export($hosts);

application/controllers/ServicegroupController.php

@@ -65,7 +65,7 @@ class ServicegroupController extends Controller
         $paginationControl = $this->createPaginationControl($services);
         $viewModeSwitcher = $this->createViewModeSwitcher($paginationControl, $limitControl);
 
-        $serviceList = (new ServiceList($services))
+        $serviceList = (new ServiceList($services->execute()))
             ->setViewMode($viewModeSwitcher->getViewMode());
 
         yield $this->export($services);

library/Icingadb/Redis/VolatileStateResults.php

@@ -4,6 +4,7 @@
 
 namespace Icinga\Module\Icingadb\Redis;
 
+use Exception;
 use Generator;
 use Icinga\Application\Benchmark;
 use Icinga\Module\Icingadb\Common\IcingaRedis;
@@ -12,6 +13,7 @@ use Icinga\Module\Icingadb\Model\Service;
 use ipl\Orm\Query;
 use ipl\Orm\Resolver;
 use ipl\Orm\ResultSet;
+use Predis\Client;
 use RuntimeException;
 
 class VolatileStateResults extends ResultSet
@@ -19,6 +21,9 @@ class VolatileStateResults extends ResultSet
     /** @var Resolver */
     private $resolver;
 
+    /** @var Client */
+    private $redis;
+
     /** @var bool Whether Redis updates were applied */
     private $updatesApplied = false;
 
@@ -27,12 +32,28 @@ class VolatileStateResults extends ResultSet
         $self = parent::fromQuery($query);
         $self->resolver = $query->getResolver();
 
+        try {
+            $self->redis = IcingaRedis::instance()->getConnection();
+        } catch (Exception $e) {
+            // The error has already been logged
+        }
+
         return $self;
     }
 
+    /**
+     * Get whether Redis is unavailable
+     *
+     * @return bool
+     */
+    public function isRedisUnavailable(): bool
+    {
+        return $this->redis === null;
+    }
+
     public function current()
     {
-        if (! $this->updatesApplied && ! $this->isCacheDisabled) {
+        if ($this->redis && ! $this->updatesApplied && ! $this->isCacheDisabled) {
             $this->rewind();
         }
 
@@ -41,7 +62,7 @@ class VolatileStateResults extends ResultSet
 
     public function key(): int
     {
-        if (! $this->updatesApplied && ! $this->isCacheDisabled) {
+        if ($this->redis && ! $this->updatesApplied && ! $this->isCacheDisabled) {
             $this->rewind();
         }
 
@@ -50,7 +71,7 @@ class VolatileStateResults extends ResultSet
 
     public function rewind(): void
     {
-        if (! $this->updatesApplied && ! $this->isCacheDisabled) {
+        if ($this->redis && ! $this->updatesApplied && ! $this->isCacheDisabled) {
             $this->updatesApplied = true;
             $this->advance();
 
@@ -126,7 +147,7 @@ class VolatileStateResults extends ResultSet
 
     protected function fetchStates(string $key, array $ids, array $keys): Generator
     {
-        $results = IcingaRedis::instance()->getConnection()->hmget($key, $ids);
+        $results = $this->redis->hmget($key, $ids);
         foreach ($results as $i => $json) {
             if ($json !== null) {
                 $data = json_decode($json, true);

library/Icingadb/Widget/ItemList/StateList.php

@@ -7,6 +7,9 @@ namespace Icinga\Module\Icingadb\Widget\ItemList;
 use Icinga\Module\Icingadb\Common\BaseItemList;
 use Icinga\Module\Icingadb\Common\NoSubjectLink;
 use Icinga\Module\Icingadb\Common\ViewMode;
+use Icinga\Module\Icingadb\Redis\VolatileStateResults;
+use Icinga\Module\Icingadb\Widget\Notice;
+use ipl\Html\HtmlDocument;
 
 abstract class StateList extends BaseItemList
 {
@@ -18,5 +21,11 @@ abstract class StateList extends BaseItemList
         $this->addAttributes(['class' => $this->getViewMode()]);
 
         parent::assemble();
+
+        if ($this->data instanceof VolatileStateResults && $this->data->isRedisUnavailable()) {
+            $this->prependWrapper((new HtmlDocument())->addHtml(new Notice(
+                t('Icinga Redis is currently unavailable. The shown information might be outdated.')
+            )));
+        }
     }
 }

library/Icingadb/Widget/Notice.php

@@ -0,0 +1,31 @@
+<?php
+
+/* Icinga DB Web | (c) 2022 Icinga GmbH | GPLv2 */
+
+namespace Icinga\Module\Icingadb\Widget;
+
+use ipl\Html\BaseHtmlElement;
+use ipl\Html\HtmlElement;
+use ipl\Web\Widget\Icon;
+
+class Notice extends BaseHtmlElement
+{
+    /** @var mixed */
+    protected $content;
+
+    protected $tag = 'p';
+
+    protected $defaultAttributes = ['class' => 'notice'];
+
+    public function __construct($content)
+    {
+        $this->content = $content;
+    }
+
+    protected function assemble()
+    {
+        $this->addHtml(new Icon('triangle-exclamation'));
+        $this->addHtml((new HtmlElement('span'))->add($this->content));
+        $this->addHtml(new Icon('triangle-exclamation'));
+    }
+}

public/css/common.less

@@ -185,6 +185,10 @@ div.show-more {
   .show-more {
     margin-top: .25em;
   }
+
+  .notice {
+    display: none;
+  }
 }
 
 .content > h2:first-child,

public/css/widget/notice.less

@@ -0,0 +1,23 @@
+// Style
+
+.notice {
+  @margin: 1em / 1.25;
+  @padding: .75em / 1.25;
+
+  .rounded-corners();
+  padding: @padding;
+  color: @text-color-on-icinga-blue;
+  background-color: @state-warning;
+  font-weight: bold;
+  font-size: 1.25em;
+
+  // Layout
+  display: flex;
+  align-items: baseline;
+  justify-content: space-between;
+  margin: 0 @margin @margin @margin;
+
+  > span {
+    .text-ellipsis();
+  }
+}