composer.json

{
    "require": {
        "php": ">=5.4.0",
        "elasticsearch/elasticsearch": "~1.3"
    }
}

magentoes.php

<?php
require_once 'vendor/autoload.php';

run();

function run()
{
    $es = elasticClient();
    createProductsIndex($es);

    $oauth = getOAuth();
    $products = queryProducts($oauth);

    foreach ($products as $product) {
        indexProduct($es, $oauth, $product);
    }
}

function elasticClient()
{
    return new Elasticsearch\Client(
        [
            'hosts' => [
                'https://szj7ontc09:j0iam1qjhk@httplabsstaging-8492688318.eu-west-1.bonsai.io:443'
            ]
        ]
    );
}

function indexProduct($es, $oauth, $product)
{
    echo "Indexing product {$product->entity_id}; '{$product->sku}'; '{$product->name}'".PHP_EOL;
    $product->categories = queryProductData($oauth, $product->entity_id, 'categories');
    $product->images = queryProductData($oauth, $product->entity_id, 'images');
    $es->index(
        [
            'body' => $product,
            'index' => 'products',
            'type' => 'product'
        ]
    );
}

function createProductsIndex($es)
{
    $es->indices()->delete(['index' => 'products']);
    $es->indices()->create(['index' => 'products']);
}
function queryProducts($oauth)
{
    try {
        $result = $oauth->fetch('http://magentofrontend.dev/api/rest/products', array(), 'GET', array('Content-Type' => 'application/json'));
        if ($result) {
            return json_decode($oauth->getLastResponse());
        }
    } catch(OAuthException $e) {
        print_r($e);
    }

    return [];
}
function queryProductData($oauth, $id, $resource)
{
    $result = $oauth->fetch("http://magentofrontend.dev/api/rest/products/{$id}/{$resource}", array(), 'GET', array('Content-Type' => 'application/json'));
    if ($result) {
        $data = json_decode($oauth->getLastResponse());
        return $data;
    }
}

function getOAuth()
{
        $oauth = new OAuth('9305535f38b6eb02cb3041755b0ffd41', 'ccb72ae66658a11e5f60639782324fcd');
        $oauth->enableDebug();

        if(file_exists('token')) {
            $token = json_decode(file_get_contents('token'));
            $oauth->setToken($token->oauth_token, $token->oauth_token_secret);
            return $oauth;
        }

        $rtoken = $oauth->getRequestToken('http://magentofrontend.dev/oauth/initiate', '');
        echo '1. Click this link to authorize, '.'http://magentofrontend.dev/admin/oauth_authorize?oauth_token='.$rtoken['oauth_token'].PHP_EOL;
        echo '2. Enter "Verifier code": ';

        $handle = fopen('php://stdin', 'r');
        $line = fgets($handle);

        $oauth->setToken($rtoken['oauth_token'], $rtoken['oauth_token_secret']);
        $token = $oauth->getAccessToken('http://magentofrontend.dev/oauth/token', '', trim($line));
        file_put_contents('token', json_encode($token));

        $oauth->setToken($token['oauth_token'], $token['oauth_token_secret']);
        return $oauth;
}