feature: support non-standard unix socket (#5724)

* Add support for custom MySQL unix-socket

* NULL must be lowercase!

* Naive edit of html/install.php

* fixup

* Refactor dbConnect
Use it everywhere

* $config needs to be global
Don't need to set $database_link

* small cleanups

LibreNMS/Exceptions/DatabaseConnectException.php

@@ -0,0 +1,31 @@
+<?php
+/**
+ * DatabaseConnectException.php
+ *
+ * -Description-
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * @package    LibreNMS
+ * @link       http://librenms.org
+ * @copyright  2017 Tony Murray
+ * @author     Tony Murray <murraytony@gmail.com>
+ */
+
+namespace LibreNMS\Exceptions;
+
+class DatabaseConnectException extends \Exception
+{
+
+}

LibreNMS/IRCBot.php

@@ -20,6 +20,8 @@
 
 namespace LibreNMS;
 
+use LibreNMS\Exceptions\DatabaseConnectException;
+
 class IRCBot
 {
 
@@ -365,7 +367,7 @@ class IRCBot
     }//end getUser()
 
 
-    private function connect($try)
+    private function connect($try = 0)
     {
         if ($try > $this->max_retry) {
             $this->log('Failed too many connection attempts, aborting');
@@ -437,15 +439,21 @@ class IRCBot
     private function chkdb()
     {
         if (!is_resource($this->sql)) {
-            if (($this->sql = mysqli_connect($this->config['db_host'], $this->config['db_user'], $this->config['db_pass'], null, $this->config['db_port'])) != false && mysqli_select_db($this->sql, $this->config['db_name'])) {
-                return true;
-            } else {
-                $this->log('Cannot connect to MySQL');
+            try {
+                $this->sql = dbConnect(
+                    $this->config['db_host'],
+                    $this->config['db_user'],
+                    $this->config['db_pass'],
+                    $this->config['db_name'],
+                    $this->config['db_port'],
+                    $this->config['db_socket']
+                );
+            } catch (DatabaseConnectException $e) {
+                $this->log('Cannot connect to MySQL: ' . $e->getMessage());
                 return die();
             }
-        } else {
-            return true;
         }
+        return true;
     }//end chkdb()