NoNodesAvailableException in StaticNoPingConnectionPool.php : No alive nodes found in your cluster

I use elasticsearch v 5.5.2 with laravel 5.3 - scout v -2.0.

I a trying to executing below code but I am getting this error. NoNodesAvailableException.

namespace App\Http\Controllers;

use Illuminate\Http\Request;
use Elasticsearch\ClientBuilder;
use Elastica\Client as ElasticaClient;

class clientController extends Controller
{
    protected $elasticsearch;
    protected $elastica;
    public function __construct()
    {
        $this->elasticsearch = ClientBuilder::create()
                //->setConnectionPool('\Elasticsearch\ConnectionPool\SniffingConnectionPool', [])
                ->build();
        $elasticConfig=['host'=>"locahost",
            "port"=>9200,
            "index"=>'pets'];
        $this->elastica = new  ElasticaClient($elasticConfig);
    }
    public function elasticsearchTest(){

        $param = [
            'index' => 'pets',
            'type' => 'dog',
            'id'=>'1'
        ];
        $res = $this->elasticsearch->get($param);
        dump($res); 
    }
}

Error

NoNodesAvailableException in StaticNoPingConnectionPool.php line 51: No alive nodes found in your cluster

via Chebli Mohamed