IcingaHealth: Fix version comparison

There are multiple possible outputs for an Icinga DB version. The
package version contain the git tag, with a leading "v". The development
version mimics git-describe(1), including a commit hash separated by a
dash after the semantic version.

The current version comparison uses PHP's builtin version_compare().

This results in leading "v"s to return invalid results. Furthermore, it
treats everything behind the version as an "any string"[^0], which is
smaller than dev, alpha, beta, and so on. Thus, any git-describe(1)
version of Icinga DB 1.4.0 would be considered smaller as 1.4.0.

Fixes #1230.

[^0]: https://www.php.net/manual/en/function.version-compare.php

library/Icingadb/ProvidedHook/IcingaHealth.php

@@ -16,6 +16,24 @@ class IcingaHealth extends HealthHook
 
     public const REQUIRED_ICINGADB_VERSION = '1.4.0';
 
+    /**
+     * normalizeVersion extracts a version string from Icinga DB's reported
+     * version comparable with REQUIRED_ICINGADB_VERSION via version_compare.
+     *
+     * @param string $version Icinga DB version string to normalize.
+     *
+     * @return string Normalized Icinga DB version string.
+     */
+    public static function normalizeVersion(string $version): string
+    {
+        // Ignore leading "v" when the git tag is used, e.g., "v1.4.0".
+        $version = ltrim($version, 'v');
+        // Ignore everything after "-" used by git describe, e.g., "1.4.0-g...".
+        $version = explode('-', $version, 2)[0];
+
+        return $version;
+    }
+
     /** @var Instance */
     protected $instance;
 
@@ -47,7 +65,11 @@ class IcingaHealth extends HealthHook
             ));
         } elseif (
             ! isset($instance->icingadb_version)
-            || version_compare($instance->icingadb_version, self::REQUIRED_ICINGADB_VERSION, '<')
+            || version_compare(
+                self::normalizeVersion($instance->icingadb_version),
+                self::REQUIRED_ICINGADB_VERSION,
+                '<'
+            )
         ) {
             $this->setState(self::STATE_CRITICAL);
             $this->setMessage(sprintf(

library/Icingadb/Widget/Health.php

@@ -26,7 +26,11 @@ class Health extends BaseHtmlElement
     {
         if (
             ! isset($this->data->icingadb_version)
-            || version_compare($this->data->icingadb_version, IcingaHealth::REQUIRED_ICINGADB_VERSION, '<')
+            || version_compare(
+                IcingaHealth::normalizeVersion($this->data->icingadb_version),
+                IcingaHealth::REQUIRED_ICINGADB_VERSION,
+                '<'
+            )
         ) {
             $this->addHtml(Html::tag('div', ['class' => 'icinga-health down'], [
                 sprintf(