implementation DB::$defaultOptions

.env.example

@@ -8,3 +8,8 @@ REDIS_HOST=redis
 REDIS_PASSWORD=
 REDIS_PORT=6379
 REDIS_DB=0
+MYSQL_HOST=mysql
+MYSQL_PORT=3306
+MYSQL_USER=mysql
+MYSQL_PASSWORD=mysql
+MYSQL_DB=db

README.md

@@ -50,6 +50,33 @@ php index.php
 ```
 
 ### Example
+```php
+/**
+ * Set redis options
+ * @see https://github.com/promphp/prometheus_client_php#usage
+ */
+RedisStorage::setDefaultOptions([
+    'host' => 'redis',
+    'port' => 6379,
+    'password' => null,
+    'database' => 0,
+    'timeout' => 0.1, // in seconds
+    'read_timeout' => '10', // in seconds
+    'persistent_connections' => false
+]);
+
+/**
+ * Set mysql options
+ */
+DB::setDefaultOptions([
+    'host' => 'mysql',
+    'port' => '3306',
+    'user' => 'mysql',
+    'password' => 'mysql',
+    'db' => 'db'
+]);
+```
+
 ```php
 // Example gauge from mysql
 $gauge = $registry->getOrRegisterGauge('rpe', 'testTable', 'Value from mysql');

index.php

@@ -39,6 +39,17 @@
     'persistent_connections' => false,
 ]);
 
+/**
+ * Set mysql options
+ */
+DB::setDefaultOptions([
+    'host' => $_ENV['MYSQL_HOST'] ? $_ENV['MYSQL_HOST'] : 'mysql',
+    'port' => $_ENV['MYSQL_PORT'] ? $_ENV['MYSQL_PORT'] : '3306',
+    'user' => $_ENV['MYSQL_USER'] ? $_ENV['MYSQL_USER'] : 'mysql',
+    'password' => $_ENV['MYSQL_PASSWORD'] ? $_ENV['MYSQL_PASSWORD'] : 'mysql',
+    'db' => $_ENV['MYSQL_DB'] ? $_ENV['MYSQL_DB'] : 'db',
+]);
+
 try {
     $registry = new CollectorRegistry(new RedisStorage(), false);
 } catch (\Exception $e) {

src/DB.php

@@ -37,15 +37,42 @@ class DB {
      */
     private Credentials $credentials;
 
+    /**
+     * Credentials options
+     * @var string[]
+     */
+    private static array $defaultOptions = [
+        'host' => 'mysql',
+        'port' => '3306',
+        'user' => 'mysql',
+        'password' => 'mysql',
+        'db' => 'db',
+    ];
+
+    /**
+     * @param mixed[] $options
+     */
+    public static function setDefaultOptions(array $options): void {
+        self::$defaultOptions = array_merge(self::$defaultOptions, $options);
+    }
+
     /**
      * DB constructor
+     * @param array $options
      */
-    public function __construct() {
+    public function __construct($options = []) {
         $loop = ReactAdapter::get();
+        self::setDefaultOptions($options);
 
         $this->driver = new MysqlDriver($loop);
         $this->platform = new MySqlPlatform();
-        $this->credentials = new Credentials('mysql', '3306', 'mysql', 'mysql', 'db');
+        $this->credentials = new Credentials(
+            self::$defaultOptions['host'],
+            self::$defaultOptions['port'],
+            self::$defaultOptions['user'],
+            self::$defaultOptions['password'],
+            self::$defaultOptions['db']
+        );
 
         $this->conn = SingleConnection::createConnected($this->driver, $this->credentials, $this->platform);