1 files changed, 222 insertions, 0 deletions
diff --git a/library/Icinga/Application/Hook/HealthHook.php b/library/Icinga/Application/Hook/HealthHook.php
new file mode 100644
index 0000000..f6420b5
--- /dev/null
+++ b/library/Icinga/Application/Hook/HealthHook.php
@@ -0,0 +1,222 @@
+<?php
+/* Icinga Web 2 | (c) 2021 Icinga GmbH | GPLv2+ */
+
+namespace Icinga\Application\Hook;
+
+use Exception;
+use Icinga\Application\Hook;
+use Icinga\Application\Logger;
+use Icinga\Data\DataArray\ArrayDatasource;
+use Icinga\Exception\IcingaException;
+use ipl\Web\Url;
+use LogicException;
+
+abstract class HealthHook
+{
+    /** @var int */
+    const STATE_OK = 0;
+
+    /** @var int */
+    const STATE_WARNING = 1;
+
+    /** @var int */
+    const STATE_CRITICAL = 2;
+
+    /** @var int */
+    const STATE_UNKNOWN = 3;
+
+    /** @var int The overall state */
+    protected $state;
+
+    /** @var string Message describing the overall state */
+    protected $message;
+
+    /** @var array Available metrics */
+    protected $metrics;
+
+    /** @var Url Url to a graphical representation of the available metrics */
+    protected $url;
+
+    /**
+     * Get overall state
+     *
+     * @return int
+     */
+    public function getState()
+    {
+        return $this->state;
+    }
+
+    /**
+     * Set overall state
+     *
+     * @param int $state
+     *
+     * @return $this
+     */
+    public function setState($state)
+    {
+        $this->state = $state;
+
+        return $this;
+    }
+
+    /**
+     * Get the message describing the overall state
+     *
+     * @return string
+     */
+    public function getMessage()
+    {
+        return $this->message;
+    }
+
+    /**
+     * Set the message describing the overall state
+     *
+     * @param string $message
+     *
+     * @return $this
+     */
+    public function setMessage($message)
+    {
+        $this->message = $message;
+
+        return $this;
+    }
+
+    /**
+     * Get available metrics
+     *
+     * @return array
+     */
+    public function getMetrics()
+    {
+        return $this->metrics;
+    }
+
+    /**
+     * Set available metrics
+     *
+     * @param array $metrics
+     *
+     * @return $this
+     */
+    public function setMetrics(array $metrics)
+    {
+        $this->metrics = $metrics;
+
+        return $this;
+    }
+
+    /**
+     * Get the url to a graphical representation of the available metrics
+     *
+     * @return Url
+     */
+    public function getUrl()
+    {
+        return $this->url;
+    }
+
+    /**
+     * Set the url to a graphical representation of the available metrics
+     *
+     * @param Url $url
+     *
+     * @return $this
+     */
+    public function setUrl(Url $url)
+    {
+        $this->url = $url;
+
+        return $this;
+    }
+
+    /**
+     * Collect available health data from hooks
+     *
+     * @return ArrayDatasource
+     */
+    final public static function collectHealthData()
+    {
+        $checks = [];
+        foreach (Hook::all('health') as $hook) {
+            /** @var self $hook */
+
+            try {
+                $hook->checkHealth();
+                $url = $hook->getUrl();
+                $state = $hook->getState();
+                $message = $hook->getMessage();
+                $metrics = $hook->getMetrics();
+            } catch (Exception $e) {
+                Logger::error('Failed to check health: %s', $e);
+
+                $state = self::STATE_UNKNOWN;
+                $message = IcingaException::describe($e);
+                $metrics = null;
+                $url = null;
+            }
+
+            $checks[] = (object) [
+                'module'    => $hook->getModuleName(),
+                'name'      => $hook->getName(),
+                'url'       => $url ? $url->getAbsoluteUrl() : null,
+                'state'     => $state,
+                'message'   => $message,
+                'metrics'   => (object) $metrics
+            ];
+        }
+
+        return (new ArrayDatasource($checks))
+            ->setKeyColumn('name');
+    }
+
+    /**
+     * Get the name of the hook
+     *
+     * Only used in API responses to differentiate it from other hooks of the same module.
+     *
+     * @return string
+     */
+    public function getName()
+    {
+        $classPath = get_class($this);
+        $parts = explode('\\', $classPath);
+        $className = array_pop($parts);
+
+        if (substr($className, -4) === 'Hook') {
+            $className = substr($className, 1, -4);
+        }
+
+        return strtolower($className[0]) . substr($className, 1);
+    }
+
+    /**
+     * Get the name of the module providing this hook
+     *
+     * @return string
+     *
+     * @throws LogicException
+     */
+    public function getModuleName()
+    {
+        $classPath = get_class($this);
+        if (substr($classPath, 0, 14) !== 'Icinga\\Module\\') {
+            throw new LogicException('Not a module hook');
+        }
+
+        $withoutPrefix = substr($classPath, 14);
+        return strtolower(substr($withoutPrefix, 0, strpos($withoutPrefix, '\\')));
+    }
+
+    /**
+     * Check health
+     *
+     * Implement this method and set the overall state, message, url and metrics.
+     *
+     * @return void
+     */
+    abstract public function checkHealth();
+}