enable_ipv6: false is ignored within docker-compose.yml

[DerLinkman]

Description

The PR #46455 introduced a change on how the daemon setup ipv6 inside a docker network.

However, this change forcibly activates ipv6 when in a network declaration a ipv6 subnet exists even if the enable_ipv6 parameter strictly disabled ipv6 (enable_ipv6: false) as intended.

This cause the internal network communication to fail or to be slow as they are trying to talk over ipv6 which they can't.

Reproduce

1. Create a Docker Network in a docker-compose.yml with a ipv4 and ipv6 subnet and the parameter enable_ipv6: false
2. DO NOT set the native IPv6 NAT implementation inside the daemon.json
3. Startup the service
4. Ping a container via it's internal DNS name
5. See a try via IPv6 which failes as the containers have a ipv6 address but no enabled_ipv6 option.

Expected behavior

Previously the network was not created with a ipv6 subnet as the enabled_ipv6 parameters were set to false.

docker version

Client: Docker Engine - Community
 Version:           25.0.0
 API version:       1.44
 Go version:        go1.21.6
 Git commit:        e758fe5
 Built:             Thu Jan 18 17:09:59 2024
 OS/Arch:           linux/amd64
 Context:           default

Server: Docker Engine - Community
 Engine:
  Version:          25.0.0
  API version:      1.44 (minimum version 1.24)
  Go version:       go1.21.6
  Git commit:       615dfdf
  Built:            Thu Jan 18 17:09:59 2024
  OS/Arch:          linux/amd64
  Experimental:     false
 containerd:
  Version:          1.6.27
  GitCommit:        a1496014c916f9e62104b33d1bb5bd03b0858e59
 runc:
  Version:          1.1.11
  GitCommit:        v1.1.11-0-g4bccb38
 docker-init:
  Version:          0.19.0
  GitCommit:        de40ad0

docker info

Client: Docker Engine - Community
 Version:    25.0.0
 Context:    default
 Debug Mode: false
 Plugins:
  buildx: Docker Buildx (Docker Inc.)
    Version:  v0.12.1
    Path:     /usr/libexec/docker/cli-plugins/docker-buildx
  compose: Docker Compose (Docker Inc.)
    Version:  v2.24.1
    Path:     /usr/libexec/docker/cli-plugins/docker-compose
  scan: Docker Scan (Docker Inc.)
    Version:  v0.23.0
    Path:     /usr/libexec/docker/cli-plugins/docker-scan

Server:
 Containers: 5
  Running: 0
  Paused: 0
  Stopped: 5
 Images: 32
 Server Version: 25.0.0
 Storage Driver: overlay2
  Backing Filesystem: extfs
  Supports d_type: true
  Using metacopy: false
  Native Overlay Diff: true
  userxattr: false
 Logging Driver: json-file
 Cgroup Driver: systemd
 Cgroup Version: 2
 Plugins:
  Volume: local
  Network: bridge host ipvlan macvlan null overlay
  Log: awslogs fluentd gcplogs gelf journald json-file local splunk syslog
 Swarm: inactive
 Runtimes: io.containerd.runc.v2 runc
 Default Runtime: runc
 Init Binary: docker-init
 containerd version: a1496014c916f9e62104b33d1bb5bd03b0858e59
 runc version: v1.1.11-0-g4bccb38
 init version: de40ad0
 Security Options:
  apparmor
  seccomp
   Profile: builtin
  cgroupns
 Kernel Version: 6.1.0-17-amd64
 Operating System: Debian GNU/Linux 12 (bookworm)
 OSType: linux
 Architecture: x86_64
 CPUs: 12
 Total Memory: 15.62GiB
 Name: develcow
 ID: ce43ed34-587d-4366-9a8c-d0bf35a9e3fc
 Docker Root Dir: /var/lib/docker
 Debug Mode: false
 Username: derlinkman
 Experimental: false
 Insecure Registries:
  127.0.0.0/8
 Live Restore Enabled: false

Additional Info

Referencing: mailcow/mailcow-dockerized#5664 & mailcow/mailcow-dockerized#5668

[DerLinkman]

Any news here? Do you need more informations?

[kovacs-andras]

This is a problem for me too.

[akerouanton]

#47310 has been merged; this regression should be fixed in v25.0.3.

[DerLinkman]

Many thanks!