Hi,

Since environment variables are global, I think they should be prefixed by `LOCALSTACK_` in the docker image. For example `SERVICES` environment variable might conflict at some point with something else, so naming it `LOCALSTACK_SERVICES` would be nicer.

This could be optional to avoid breaking changes. Localstack would look for `LOCALSTACK_SERVICES` first, and if it's not defined would fallback to `SERVICES` just as today.

As far as I know, most (maybe all) official docker images do this. I think it's a good practice. See:
- https://hub.docker.com/_/postgres
- https://hub.docker.com/_/nginx
- https://hub.docker.com/_/mysql

Thanks.
""" Returns: True if running in a docker container, else False """
    if not os.path.exists('/proc/1/cgroup'):
        return False
    with open('/proc/1/cgroup', 'rt') as ifh:
        return 'docker' in ifh.read()
DOCKER_BRIDGE_IP = '172.17.0.1'
try:
    DOCKER_HOST_FROM_CONTAINER = socket.gethostbyname('host.docker.internal')
    
    if in_docker() and LOCALSTACK_HOSTNAME == DOCKER_BRIDGE_IP:
        LOCALSTACK_HOSTNAME = DOCKER_HOST_FROM_CONTAINER
except socket.error:
    DOCKER_HOST_FROM_CONTAINER = DOCKER_BRIDGE_IP
if in_docker() and not os.environ.get('LAMBDA_REMOTE_DOCKER', '').strip():
    LAMBDA_REMOTE_DOCKER = True
CONFIG_FILE_PATH = os.path.join(expanduser('~'), '.localstack')