Added option to force IPv4 addresses when resolving hostnames (#45)

README.md

@@ -92,6 +92,20 @@ $client->setCAPath("/ca/path"); // if you need.
 
 *Note:* Certificate must match with host name in `Client` address (`localhost` in example above).
 
+### DNS Resolution
+
+This error may indicate your system is having trouble resolving IPv6 addresses:
+
+```
+cURL error: Resolving timed out after [value] milliseconds
+```
+
+By default, both IPv4 and IPv6 addresses will attempt to be resolved. You can force it to only resolve IPv4 addresses with:
+
+```php
+$client->forceIpResolveV4();
+```
+
 ### Testing
 
 Requirements:

src/Client.php

@@ -18,6 +18,7 @@ class Client
 
     private $connectTimeoutOption;
     private $timeoutOption;
+    private $forceIpResolveV4;
 
     private $safety = true;
     private $useAssoc = false;
@@ -117,6 +118,17 @@ public function setTimeoutOption($timeoutOption)
         return $this;
     }
 
+    /**
+     * Forces DNS to only resolve IPv4 addresses.
+     *
+     * @return Client
+     */
+    public function forceIpResolveV4()
+    {
+        $this->forceIpResolveV4 = true;
+        return $this;
+    }
+
     /**
      * Publish data into channel.
      *
@@ -381,6 +393,9 @@ private function request($method, $params)
         if ($this->timeoutOption) {
             curl_setopt($ch, CURLOPT_TIMEOUT, $this->timeoutOption);
         }
+        if ($this->forceIpResolveV4) {
+            curl_setopt($ch, CURLOPT_IPRESOLVE, CURL_IPRESOLVE_V4);
+        }
         if (!$this->safety) {
             curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);
             curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, 0);