Docker 4.35.0 listens on port 8888, preventing mapping container ports to 8888 #7468

Description

Moving from Docker for Mac 4.34.3 to 4.35.0, with no user containers running, the com.docker.backend process has started listening (with an HTTP server, it seems) on IPv6 port 8888:

com.docker.backend      2469 richard.moats   46u  IPv6 0xbf4e0784a52b6017      0t0  TCP *:8888 (LISTEN)

Starting a container that exposes a port mapped to port 8888 thus fails:

ERROR: for config-backend  Cannot start service config-backend: Ports are not available: exposing port TCP 0.0.0.0:8888 -> 0.0.0.0:0: listen tcp4 0.0.0.0:8888: bind: address already in use

Reproduce

1. docker run -it --rm -p 8888:8888/tcp nginx:alpine

result:

docker: Error response from daemon: Ports are not available: exposing port TCP 0.0.0.0:8888 -> 0.0.0.0:0: listen tcp4 0.0.0.0:8888: bind: address already in use.

Expected behavior

Docker should not block containers from exposing an IP port on any host IP port.

docker version

Client:
Version: 27.3.1
API version: 1.47
Go version: go1.22.7
Git commit: ce12230
Built: Fri Sep 20 11:38:18 2024
OS/Arch: darwin/arm64
Context: desktop-linux

Server: Docker Desktop 4.35.0 (172550)
Engine:
Version: 27.3.1
API version: 1.47 (minimum version 1.24)
Go version: go1.22.7
Git commit: 41ca978
Built: Fri Sep 20 11:41:19 2024
OS/Arch: linux/arm64
Experimental: true
containerd:
Version: 1.7.21
GitCommit: 472731909fa34bd7bc9c087e4c27943f9835f111
runc:
Version: 1.1.13
GitCommit: v1.1.13-0-g58aa920
docker-init:
Version: 0.19.0
GitCommit: de40ad0

docker info

Client:
Version: 27.3.1
Context: desktop-linux
Debug Mode: false
Plugins:
buildx: Docker Buildx (Docker Inc.)
Version: v0.17.1-desktop.1
Path: /Users/richard.moats/.docker/cli-plugins/docker-buildx
compose: Docker Compose (Docker Inc.)
Version: v2.29.7-desktop.1
Path: /Users/richard.moats/.docker/cli-plugins/docker-compose
debug: Get a shell into any image or container (Docker Inc.)
Version: 0.0.37
Path: /Users/richard.moats/.docker/cli-plugins/docker-debug
desktop: Docker Desktop commands (Alpha) (Docker Inc.)
Version: v0.0.15
Path: /Users/richard.moats/.docker/cli-plugins/docker-desktop
dev: Docker Dev Environments (Docker Inc.)
Version: v0.1.2
Path: /Users/richard.moats/.docker/cli-plugins/docker-dev
extension: Manages Docker extensions (Docker Inc.)
Version: v0.2.27
Path: /Users/richard.moats/.docker/cli-plugins/docker-extension
feedback: Provide feedback, right in your terminal! (Docker Inc.)
Version: v1.0.5
Path: /Users/richard.moats/.docker/cli-plugins/docker-feedback
init: Creates Docker-related starter files for your project (Docker Inc.)
Version: v1.3.0
Path: /Users/richard.moats/.docker/cli-plugins/docker-init
sbom: View the packaged-based Software Bill Of Materials (SBOM) for an image (Anchore Inc.)
Version: 0.6.0
Path: /Users/richard.moats/.docker/cli-plugins/docker-sbom
scout: Docker Scout (Docker Inc.)
Version: v1.14.0
Path: /Users/richard.moats/.docker/cli-plugins/docker-scout

Server:
Containers: 1
Running: 1
Paused: 0
Stopped: 0
Images: 57
Server Version: 27.3.1
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: cgroupfs
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: 472731909fa34bd7bc9c087e4c27943f9835f111
runc version: v1.1.13-0-g58aa920
init version: de40ad0
Security Options:
seccomp
Profile: unconfined
cgroupns
Kernel Version: 6.10.11-linuxkit
Operating System: Docker Desktop
OSType: linux
Architecture: aarch64
CPUs: 4
Total Memory: 11.67GiB
Name: docker-desktop
ID: 31c6a73d-4b64-4309-a72e-e197d14b06c1
Docker Root Dir: /var/lib/docker
Debug Mode: false
HTTP Proxy: http.docker.internal:3128
HTTPS Proxy: http.docker.internal:3128
No Proxy: hubproxy.docker.internal
Labels:
com.docker.desktop.address=unix:///Users/richard.moats/Library/Containers/com.docker.docker/Data/docker-cli.sock
Experimental: true
Insecure Registries:
hubproxy.docker.internal:5555
127.0.0.0/8
Registry Mirrors:
https://mirror.tangocard.io/
Live Restore Enabled: false

WARNING: daemon is not using the default seccomp profile

Diagnostics ID

7715A2E9-189F-406A-B363-C08F447CF458/20241028185123

Additional Info

No response