Example working with existing OpenSearch index

[ghost]

Hey everyone,
I am trying to set up an OpenSearchDocumentStore from an existing OpenSearch index, but I'm not sure how to use open_search_index_to_document_store() properly. Is there a working example I can use for guidance? The docs here unfortunately only include the function call and I'm running into errors with my own attempts.

My attempt so far:
First I create a new, empty index

import opensearchpy
from opensearchpy import OpenSearch

host = "myhost.com"
port = 9200
auth = ('admin', 'admin')

client = OpenSearch(
    hosts = [{"host": host, "port": port}],
    http_auth = auth,
    use_ssl = True,
    verify_certs = False,
    ssl_assert_hostname = False,
    ssl_show_warn = False,
)

body = {
    "mappings":{
        "properties": {
            "id": {"type": "text"},
            "name": {"type": "text"},
            "content": {"type": "text"}
        }
    }
}
response = client.indices.create("haystack", body=body)

Next I initialize an document store with haystack:

from haystack.document_stores import OpenSearchDocumentStore, open_search_index_to_document_store

# initialize document store
document_store = OpenSearchDocumentStore(scheme="https",
                                         host=host,
                                         port=port,
                                         username="admin", 
                                         password="admin",
                                         index="haystack",
                                         content_field="content",
                                         name_field="name"
                                         )

Next I want to transform this empty document_store into a new ds:

new_ds = open_search_index_to_document_store(
    document_store=document_store,
    original_index_name="my_idx",
    original_content_field="content",
    original_name_field="name",
    port=port,
    verify_certs=False,
    scheme="https",
    username="admin",
    password="admin"
)

This, however, results in a connection error: ConnectionError: ConnectionError(<urllib3.connection.HTTPSConnection object at 0x7fd403265670>: Failed to establish a new connection: [Errno 111] Connection refused) caused by: NewConnectionError(<urllib3.connection.HTTPSConnection object at 0x7fd403265670>: Failed to establish a new connection: [Errno 111] Connection refused). This warning also seems relevant: WARNING:elasticsearch:GET https://localhost:9200/ [status:N/A request:0.001s] The host from the document_store does not appear to have been passed on, as the host and port appear to have been reverted to https://localhost:9200/. When trying to force the host back to what I want I start going down the rabbit hole outlined in #4104 which ends with an error claiming that this is not a supported product.

I don't understand what I'm doing wrong.

[dtaivpp]

@stargeysir do the first block and second block live in the same file?

[silvanocerza]

If you call open_search_index_to_document_store without passing the host argument it will default to localhost.
Is that what you intend to do?