Docker v27: Native IPv6 NAT implementation no longer experimental

[mrclschstr]

Summary

Since Docker v27, ip6tables are no longer experimental and are also active by default. See: https://docs.docker.com/engine/release-notes/27.0/#ipv6

Accordingly, a shortened daemon.json could look like this (source: https://docs.docker.com/config/daemon/ipv6/#use-ipv6-for-the-default-bridge-network):

{
  "ipv6": true,
  "fixed-cidr-v6": "2001:db8:1::/64"
}

Unfortunately, the update.sh script checks the existence of the configurations experimental: true and ip6tables: true and aborts with an error if these are not found in the daemon.json configuration. See: https://github.com/mailcow/mailcow-dockerized/blob/master/update.sh#L103

Motivation

Perhaps the check could be improved so that the configurations with Docker version >=27 no longer have to be present? Currently, however, their presence has no disadvantages.

Additional context

No response