Docker 4.26.1 breaks Xvfb USR1 signal handling when using rosetta

[rectalogic]

Description

This worked in Docker 4.25.2 (129061), but is broken in Docker 4.26.1 (131620).

I am running xvfb-run in an amd64 container on Apple Silicon mac with "Use Rosetta" enabled in Docker. This now hangs because it seems that rosetta now blocks signal USR1 that Xvfb sends.

Reproduce

Sample Dockerfile:

FROM ubuntu:jammy

RUN apt-get -y update && apt-get -y install xvfb 

ENTRYPOINT ["/usr/bin/xvfb-run", "--error-file", "/dev/stderr", "/bin/ls", "/"]

On Apple Silicon, with Rosetta enabled, these are the results I got:

Sonoma 14.2.1
Docker 4.26.1 (131620)

docker buildx build --platform=linux/amd64 --load --tag xvfb .
docker run --init --rm xvfb

# HANGS

docker buildx build --platform=linux/arm64 --load --tag xvfb .
docker run --init --rm xvfb

# WORKS

---

Ventura 13.6.3
Docker 4.25.2 (129061)

docker buildx build --platform=linux/amd64 --load --tag xvfb .
docker run --init --rm xvfb

# WORKS

docker buildx build --platform=linux/arm64 --load --tag xvfb .
docker run --init --rm xvfb

# WORKS

---

Ventura 13.6.3
Docker 4.26.1 (131620)

docker buildx build --platform=linux/amd64 --load --tag xvfb .
docker run --init --rm xvfb

# HANGS

docker buildx build --platform=linux/arm64 --load --tag xvfb .
docker run --init --rm xvfb

# WORKS

Expected behavior

USR1 should not be blocked and Xvfb should work as it did in Docker 4.25.2

docker version

Client:
 Cloud integration: v1.0.35+desktop.5
 Version:           24.0.7
 API version:       1.43
 Go version:        go1.20.10
 Git commit:        afdd53b
 Built:             Thu Oct 26 09:04:20 2023
 OS/Arch:           darwin/arm64
 Context:           desktop-linux

Server: Docker Desktop 4.26.1 (131620)
 Engine:
  Version:          24.0.7
  API version:      1.43 (minimum version 1.12)
  Go version:       go1.20.10
  Git commit:       311b9ff
  Built:            Thu Oct 26 09:08:15 2023
  OS/Arch:          linux/arm64
  Experimental:     false
 containerd:
  Version:          1.6.25
  GitCommit:        d8f198a4ed8892c764191ef7b3b06d8a2eeb5c7f
 runc:
  Version:          1.1.10
  GitCommit:        v1.1.10-0-g18a0cb0
 docker-init:
  Version:          0.19.0
  GitCommit:        de40ad0

docker info

Client:
 Version:    24.0.7
 Context:    desktop-linux
 Debug Mode: false
 Plugins:
  buildx: Docker Buildx (Docker Inc.)
    Version:  v0.12.0-desktop.2
    Path:     /Users/aw/.docker/cli-plugins/docker-buildx
  compose: Docker Compose (Docker Inc.)
    Version:  v2.23.3-desktop.2
    Path:     /Users/aw/.docker/cli-plugins/docker-compose
  dev: Docker Dev Environments (Docker Inc.)
    Version:  v0.1.0
    Path:     /Users/aw/.docker/cli-plugins/docker-dev
  extension: Manages Docker extensions (Docker Inc.)
    Version:  v0.2.21
    Path:     /Users/aw/.docker/cli-plugins/docker-extension
  feedback: Provide feedback, right in your terminal! (Docker Inc.)
    Version:  0.1
    Path:     /Users/aw/.docker/cli-plugins/docker-feedback
  init: Creates Docker-related starter files for your project (Docker Inc.)
    Version:  v0.1.0-beta.10
    Path:     /Users/aw/.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/aw/.docker/cli-plugins/docker-sbom
  scan: Docker Scan (Docker Inc.)
    Version:  v0.26.0
    Path:     /Users/aw/.docker/cli-plugins/docker-scan
  scout: Docker Scout (Docker Inc.)
    Version:  v1.2.0
    Path:     /Users/aw/.docker/cli-plugins/docker-scout

Server:
 Containers: 1
  Running: 1
  Paused: 0
  Stopped: 0
 Images: 20
 Server Version: 24.0.7
 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 logentries splunk syslog
 Swarm: inactive
 Runtimes: io.containerd.runc.v2 runc
 Default Runtime: runc
 Init Binary: docker-init
 containerd version: d8f198a4ed8892c764191ef7b3b06d8a2eeb5c7f
 runc version: v1.1.10-0-g18a0cb0
 init version: de40ad0
 Security Options:
  seccomp
   Profile: unconfined
  cgroupns
 Kernel Version: 6.5.11-linuxkit
 Operating System: Docker Desktop
 OSType: linux
 Architecture: aarch64
 CPUs: 10
 Total Memory: 4.813GiB
 Name: docker-desktop
 ID: 6df6abf4-1b71-4342-b7bd-aac30b035329
 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
 Experimental: false
 Insecure Registries:
  hubproxy.docker.internal:5555
  127.0.0.0/8
 Live Restore Enabled: false

WARNING: daemon is not using the default seccomp profile

Diagnostics ID

ECBEBC37-A545-45B6-9DCA-FCE68405FE65/20231221234212

Additional Info

This describes a similar problem where Xvfb is being run by a wrapper script that is blocking USR1 signal. I'm suspicious that since Xvfb is being run under rosetta, it is blocking the signal somehow.
https://unix.stackexchange.com/questions/244470/xvfb-not-sending-sigusr1-breaking-xvfb-run

If I docker exec into the hanging container, I see Xvfb is being run by rosetta:

UID        PID  PPID  C STIME TTY          TIME CMD
root         1     0  0 23:45 ?        00:00:00 /sbin/docker-init -- /usr/bin/xvfb-run --error-file /dev/stderr /bin/ls /
root         7     1  0 23:45 ?        00:00:00 /rosetta/rosetta /bin/sh /bin/sh /usr/bin/xvfb-run --error-file /dev/stderr /bin/ls
root        56     7  0 23:45 ?        00:00:00 /rosetta/rosetta /usr/bin/Xvfb Xvfb :99 -screen 0 1280x1024x24 -nolisten tcp -auth /
root        74     0  3 23:45 pts/0    00:00:00 /rosetta/rosetta /usr/bin/bash bash

[dgageot]

@rectalogic this will be fixed in Docker Desktop 4.27

[dgageot]

@rectalogic Could you test Docker Desktop 4.27 and close this issue if it's fixed?

[rectalogic]

Fixed, thanks.