title: Can't get the list of indexes of aws elasticsearch
body: <p>I have this python script:</p>
  
  <pre><code>from requests_aws4auth import AWS4Auth
  from elasticsearch import Elasticsearch, RequestsHttpConnection
  
  session = boto3.session.Session()
  credentials = session.get_credentials()
  awsauth = AWS4Auth(credentials.access_key,
           credentials.secret_key,
           session.region_name, 'es',
           session_token=credentials.token)
  
  
  
  es_client = Elasticsearch(
                          "vpc-mydomain-elasticsearch-xxxxxxxxx.region.es.amazonaws.com:9200",
                          http_auth=awsauth,
                          use_ssl=False,
                          verify_certs=False,
                          connection_class=RequestsHttpConnection)
  
  print(es_client.info())
  </code></pre>
  
  <p>When I run the script I get this error:</p>
  
  <pre><code>    raise ConnectionTimeout('TIMEOUT', str(e), e)
  elasticsearch.exceptions.ConnectionTimeout: ConnectionTimeout caused by - ReadTimeout(HTTPConnectionPool(host='10.0.2.2', port=3128): Read timed out. (read timeout=10))
  </code></pre>
  
  <p>The security group of the cluster has the port 9200 open for 0.0.0.0/0.
  ( <strong>10.0.2.2 is the ip address of my vagrant machine, the port 3128 is the listening port of cntlm</strong> )
  How to get this work ?</p>
  
  <p><strong>EDIT</strong></p>
  
  <p>I also tried this but it didn't work:</p>
  
  <pre><code> curl -XGET https://vpc-mydomain-elasticsearch-xxxxxxxxx.region.es.amazonaws.com:9200/_cat/indices?v
  curl: (56) Received HTTP code 403 from proxy after CONNECT
  </code></pre>