macOS Docker Desktop /dev/urandom entropy is too low.

[alan-vos]

Description

I'm using Alpine Linux 3.21.3 and I need around 1024 to 4096 bit of entropy and all I get is 256. Does anyone have a solution for this problem? Is it a bug?

I've installed "apk add haveged" and I still get 256 from /dev/urandom

Reproduce

docker run --privileged -it --rm --sysctl kernel.random.poolsize=4096 hpenc:3.0 /bin/bash invalid argument "kernel.random.poolsize=4096" for "--sysctl" flag: sysctl 'kernel.random.poolsize=4096' is not allowed

Expected behavior

No response

docker version

Client:
 Version:           28.0.1
 API version:       1.48
 Go version:        go1.23.6
 Git commit:        068a01e
 Built:             Wed Feb 26 10:38:16 2025
 OS/Arch:           darwin/arm64
 Context:           desktop-linux

Server: Docker Desktop 4.39.0 (184744)
 Engine:
  Version:          28.0.1
  API version:      1.48 (minimum version 1.24)
  Go version:       go1.23.6
  Git commit:       bbd0a17
  Built:            Wed Feb 26 10:40:57 2025
  OS/Arch:          linux/arm64
  Experimental:     false
 containerd:
  Version:          1.7.25
  GitCommit:        bcc810d6b9066471b0b6fa75f557a15a1cbf31bb
 runc:
  Version:          1.2.4
  GitCommit:        v1.2.4-0-g6c52b3f
 docker-init:
  Version:          0.19.0
  GitCommit:        de40ad0

docker info

Client:
 Version:           28.0.1
 API version:       1.48
 Go version:        go1.23.6
 Git commit:        068a01e
 Built:             Wed Feb 26 10:38:16 2025
 OS/Arch:           darwin/arm64
 Context:           desktop-linux

Server: Docker Desktop 4.39.0 (184744)
 Engine:
  Version:          28.0.1
  API version:      1.48 (minimum version 1.24)
  Go version:       go1.23.6
  Git commit:       bbd0a17
  Built:            Wed Feb 26 10:40:57 2025
  OS/Arch:          linux/arm64
  Experimental:     false
 containerd:
  Version:          1.7.25
  GitCommit:        bcc810d6b9066471b0b6fa75f557a15a1cbf31bb
 runc:
  Version:          1.2.4
  GitCommit:        v1.2.4-0-g6c52b3f
 docker-init:
  Version:          0.19.0
  GitCommit:        de40ad0
ALANG-M3:~ aguedeney$ docker info
Client:
 Version:    28.0.1
 Context:    desktop-linux
 Debug Mode: false
 Plugins:
  ai: Docker AI Agent - Ask Gordon (Docker Inc.)
    Version:  v0.9.4
    Path:     /Users/aguedeney/.docker/cli-plugins/docker-ai
  buildx: Docker Buildx (Docker Inc.)
    Version:  v0.21.1-desktop.2
    Path:     /Users/aguedeney/.docker/cli-plugins/docker-buildx
  compose: Docker Compose (Docker Inc.)
    Version:  v2.33.1-desktop.1
    Path:     /Users/aguedeney/.docker/cli-plugins/docker-compose
  debug: Get a shell into any image or container (Docker Inc.)
    Version:  0.0.38
    Path:     /Users/aguedeney/.docker/cli-plugins/docker-debug
  desktop: Docker Desktop commands (Beta) (Docker Inc.)
    Version:  v0.1.5
    Path:     /Users/aguedeney/.docker/cli-plugins/docker-desktop
  dev: Docker Dev Environments (Docker Inc.)
    Version:  v0.1.2
    Path:     /Users/aguedeney/.docker/cli-plugins/docker-dev
  extension: Manages Docker extensions (Docker Inc.)
    Version:  v0.2.27
    Path:     /Users/aguedeney/.docker/cli-plugins/docker-extension
  feedback: Provide feedback, right in your terminal! (Docker Inc.)
    Version:  v1.0.5
    Path:     /Users/aguedeney/.docker/cli-plugins/docker-feedback
  init: Creates Docker-related starter files for your project (Docker Inc.)
    Version:  v1.4.0
    Path:     /Users/aguedeney/.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/aguedeney/.docker/cli-plugins/docker-sbom
  scout: Docker Scout (Docker Inc.)
    Version:  v1.16.3
    Path:     /Users/aguedeney/.docker/cli-plugins/docker-scout

Server:
 Containers: 10
  Running: 4
  Paused: 0
  Stopped: 6
 Images: 9
 Server Version: 28.0.1
 Storage Driver: overlayfs
  driver-type: io.containerd.snapshotter.v1
 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
 CDI spec directories:
  /etc/cdi
  /var/run/cdi
 Swarm: inactive
 Runtimes: io.containerd.runc.v2 runc
 Default Runtime: runc
 Init Binary: docker-init
 containerd version: bcc810d6b9066471b0b6fa75f557a15a1cbf31bb
 runc version: v1.2.4-0-g6c52b3f
 init version: de40ad0
 Security Options:
  seccomp
   Profile: unconfined
  cgroupns
 Kernel Version: 6.10.14-linuxkit
 Operating System: Docker Desktop
 OSType: linux
 Architecture: aarch64
 CPUs: 4
 Total Memory: 2.846GiB
 Name: docker-desktop
 ID: 947dc408-2edf-4539-92a7-77c20ea6a2b7
 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/aguedeney/Library/Containers/com.docker.docker/Data/docker-cli.sock
 Experimental: false
 Insecure Registries:
  hubproxy.docker.internal:5555
  ::1/128
  127.0.0.0/8
 Live Restore Enabled: false

WARNING: daemon is not using the default seccomp profile

Diagnostics ID

7472A6C4-04D4-43F4-A84A-A63221C5AD68/20250318052939

Additional Info

Inside the container I run: cat /proc/sys/kernel/random/entropy_avail 256

[alan-vos]

I will assume at this point the Docker does not support the feature even though the host entropy is much greater than 256.