Hey all!

I'm using localstack for a project where I consume data from kinesis, process it and put it in elasticsearch.

In the later versions of localstack 'elasticsearch' was removed and is now lazily loaded after call to es::CreateElasticsearchDomain (at least that's how I understand it from #1881, #1865, #1870).

I'm running localstack in a docker using testcontainers (which gives me dynamic port mappings etc). My processing code is running on localhost.

The problem I'm facing now is that the response from es::CreateElasticsearchDomain returns an elasticsearch endpoint like: http://[docker container id]:port.
With my set up, this gives me two issues:
1. [docker container id] host is not (I believe) reachable from localhost unless I add it to /etc/hosts or something like that. I can surely "hack" my way around this by just replacing [docker container id] with localhost.
2. It says here: https://github.com/localstack/localstack/issues/1881#issuecomment-567495056 that we should not assume that elasticsearch will run on a static port in the future. When running localstack in a docker, how would I know which port to expose then in order to reach elasticsearch from localhost?

I currently have my tests running using 1.10.7 but there I just make a dummy call to es::CreateElasticsearchDomain and hardcode elasticsearch endpoint to http://localhost:4571. (It seems like it always chooses 4571 as of now?)

Thanks
Stefan
import json
import time
import logging
from random import randint
from flask import Flask, jsonify, request, make_response
from localstack.utils import persistence
from localstack.services import generic_proxy, install
from localstack.utils.aws import aws_stack
from localstack.constants import TEST_AWS_ACCOUNT_ID, ELASTICSEARCH_DEFAULT_VERSION
from localstack.utils.common import to_str
from localstack.utils.tagging import TaggingService
from localstack.utils.analytics import event_publisher
from localstack.services.plugins import check_infra
LOG = logging.getLogger(__name__)
APP_NAME = 'es_api'
API_PREFIX = '/2015-01-01'
DEFAULT_ES_VERSION = '7.1'
ES_DOMAINS = {}
TAGS = TaggingService()
app = Flask(APP_NAME)
app.url_map.strict_slashes = False
def error_response(error_type, code=400, message='Unknown error.'):