More helpful messages on db connection failures (#17789)

* Added a message map to allow translating db error messages

* Allow translation of db error message

* Also include mysql error numbers as possible detection mechanisms for errors

* Only create a new exception if we're changing the message

* Missed change

* Fixing tests

* More test fixes

* Update en.json

Use MySQL server has gone away to help people google the fix

1 files changed, 41 insertions, 6 deletions

diff --git a/core/Db/Adapter.php b/core/Db/Adapter.php
index 7beccd9c24..44263a9f50 100644
--- a/core/Db/Adapter.php
+++ b/core/Db/Adapter.php
@@ -9,6 +9,7 @@
 namespace Piwik\Db;
 
 use Zend_Db_Table;
+use Piwik\Piwik;
 
 /**
  */
@@ -45,14 +46,24 @@ class Adapter
             $infos[$key] = $val;
         }
 
-        $adapter   = new $className($infos);
+        $adapter = new $className($infos);
 
         if ($connect) {
-            $adapter->getConnection();
-
-            Zend_Db_Table::setDefaultAdapter($adapter);
-            // we don't want the connection information to appear in the logs
-            $adapter->resetConfig();
+            try {
+                $adapter->getConnection();
+
+                Zend_Db_Table::setDefaultAdapter($adapter);
+                // we don't want the connection information to appear in the logs
+                $adapter->resetConfig();
+            } catch(\Exception $e) {
+                // we don't want certain exceptions to leak information
+                $msg = self::overriddenExceptionMessage($e->getMessage());
+                if ('' !== $msg) {
+                    throw new \Exception($msg);
+                }
+
+                throw $e;
+            }
         }
 
         return $adapter;
@@ -129,4 +140,28 @@ class Adapter
     {
         return strtolower($adapterName) === 'pdo/mysql';
     }
+
+    /**
+     * Intercepts certain exception messages and replaces leaky ones with ones that don't reveal too much info
+     * @param string $message
+     * @return string
+     */
+    public static function overriddenExceptionMessage($message)
+    {
+        $safeMessageMap = array(
+            // add any exception search terms and their replacement message here
+            '[2006]'                        => Piwik::translate('General_ExceptionDatabaseUnavailable'),
+            'MySQL server has gone away'    => Piwik::translate('General_ExceptionDatabaseUnavailable'),
+            '[1698]'                        => Piwik::translate('General_ExceptionDatabaseAccess'),
+            'Access denied'                 => Piwik::translate('General_ExceptionDatabaseAccess')
+        );
+
+        foreach ($safeMessageMap as $search_term => $safeMessage) {
+            if (strpos($message, $search_term) !== false) {
+                return $safeMessage;
+            }
+        }
+
+        return '';
+    }
 }