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
config_status = get_domain_config_status()
    return {
        'DomainConfig': {
            'AccessPolicies': {
                'Options': '{"Version":"2012-10-17","Statement":[{"Effect":"Allow","Principal":{"AWS":"arn:aws:iam::%s:root"},"Action":"es:*","Resource":"arn:aws:es:%s:%s:domain/%s/*"}]}' % (TEST_AWS_ACCOUNT_ID, aws_stack.get_region(), TEST_AWS_ACCOUNT_ID, domain_name),  
                'Status': config_status
            },
            'AdvancedOptions': {
                'Options': {
                    'indices.fielddata.cache.size': '',
                    'rest.action.multi.allow_explicit_index': 'true'
                },
                'Status': config_status
            },
            'EBSOptions': {
                'Options': {
                    'EBSEnabled': True,
                    'EncryptionEnabled': False,
                    'Iops': 0,
                    'VolumeSize': 10,
                    'VolumeType': 'gp2'
                },
                'Status': config_status
            },
            'ElasticsearchClusterConfig': {
                'Options': {