docker "exec" does not forward signals to container process.

[q53]

Description

subj.

Reproduce

[16:57:37 dt]$ cat test.sh 
#!/bin/bash

CID=`docker run --name test -d --rm alpine sleep 3000`

docker exec -i test sleep 300 & # First job

sleep 30 & # Second job

sleep 3

kill -- -$$ # Terminate all jobs

[16:57:41 dt]$ ./test.sh 
Terminated
[16:57:47 dt]$ ps # are there any jos left?
 PID TTY TIME CMD
 174332 pts/20 00:00:00 bash
 177628 pts/20 00:00:00 ps
[16:57:50 dt]$ docker exec -ti test ps aux
PID USER TIME COMMAND
 1 root 0:00 sleep 3000
 7 root 0:00 sleep 300
 13 root 0:00 ps aux
[16:57:55 dt]$ 

Expected behavior

The last command shouldn't show 7 root 0:00 sleep 300 line

docker version

Client: Docker Engine - Community
 Version: 26.1.3
 API version: 1.45
 Go version: go1.21.10
 Git commit: b72abbb
 Built: Thu May 16 08:34:39 2024
 OS/Arch: linux/amd64
 Context: default

Server: Docker Engine - Community
 Engine:
 Version: 26.1.3
 API version: 1.45 (minimum version 1.24)
 Go version: go1.21.10
 Git commit: 8e96db1
 Built: Thu May 16 08:33:34 2024
 OS/Arch: linux/amd64
 Experimental: true
 containerd:
 Version: 1.6.32
 GitCommit: 8b3b7ca2e5ce38e8f31a34f35b2b68ceb8470d89
 runc:
 Version: 1.1.12
 GitCommit: v1.1.12-0-g51d5e94
 docker-init:
 Version: 0.19.0
 GitCommit: de40ad0

docker info

Client: Docker Engine - Community
 Version: 26.1.3
 Context: default
 Debug Mode: false
 Plugins:
 buildx: Docker Buildx (Docker Inc.)
 Version: v0.14.0
 Path: /usr/libexec/docker/cli-plugins/docker-buildx
 compose: Docker Compose (Docker Inc.)
 Version: v2.27.0
 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: 10
 Running: 2
 Paused: 0
 Stopped: 8
 Images: 21
 Server Version: 26.1.3
 Storage Driver: overlay2
 Backing Filesystem: xfs
 Supports d_type: true
 Using metacopy: false
 Native Overlay Diff: true
 userxattr: false
 Logging Driver: json-file
 Cgroup Driver: cgroupfs
 Cgroup Version: 1
 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: 8b3b7ca2e5ce38e8f31a34f35b2b68ceb8470d89
 runc version: v1.1.12-0-g51d5e94
 init version: de40ad0
 Security Options:
 seccomp
 Profile: builtin
 Kernel Version: 4.18.0-553.8.1.el8_10.x86_64
 Operating System: AlmaLinux 8.10 (Cerulean Leopard)
 OSType: linux
 Architecture: x86_64
 CPUs: 4
 Total Memory: 17.27GiB
 Name: n03
 ID: 83a369a6-cf0a-4b50-acac-9d12021b3b66
 Docker Root Dir: /var/lib/docker
 Debug Mode: false
 Experimental: true
 Insecure Registries:
 127.0.0.0/8
 Live Restore Enabled: false

Additional Info

No response

[thaJeztah]

This looks to be a duplicate of #2607 and moby/moby#9098

#1841 fixed this situation for docker run, but docker exec needs additional changes (some outlined in moby/moby#9098)

Let me close this one to prevent the conversation from diverging.