ldap traffic is unencrypted between haproxy and container host

[baszoetekouw]

Currently the ldap container exposes a plain text port 389 to the outside. This means that all traffic between the haproxy and ldap container is plain text, which we don't want.

There are two solutions:

1. (preferrred) loop the ldap traffic also through Traefik; according to @quartje it is also able to handle plain TCP traffic and should be able to do TLS termination. This is the preferred solution, because it allows us to treat all containers and traffic (HTTP and TCP) identical, and we don't have to expose the ldap container port on the Docker host at all.
2. let slapd handle the TLS termination and expose an ldaps-port on the container host. In that case, make sure we expose a non-standard port (e.g., 1636 instead of 636).

[mrvanes]

No, LDAP traffic flow through traefik and traefik connects to 389 on the container host. Let's discuss when I'm back.