docker on ubuntu 16.04 error when killing containe

Question

I can't kill or stop any docker container. I've allowed non-privileged users to run Docker commands. And docker run hello-world works fine. But I can't stop any other container.

I got following:

$ docker stop 59e3b815d1dc
Error response from daemon: cannot stop container: 59e3b815d1dc: 
Cannot kill container 59e3b815d1dcf2d8c8bcd3dd641c3c033b83ac68ea2f0257a32a76468af7374c: 
unknown error after kill: docker-runc did not terminate sucessfully: 
container_linux.go:393: signaling init process caused "permission denied"
: unknown

The same error with sudo. Meanwhile, all containers run successfully, but to stop them is possible only a full reboot of the system.

Docker compose example: # Use postgres/example user/password credentials version: '3.1'

services:

  db:
    image: postgres
    restart: always
    environment:
      POSTGRES_PASSWORD: example

  adminer:
    image: adminer
    restart: always
    ports:
      - 8080:8080

Docker info:

$ docker info
Containers: 7
 Running: 2
 Paused: 0
 Stopped: 5
Images: 10
Server Version: 17.12.1-ce
Storage Driver: overlay2
 Backing Filesystem: extfs
 Supports d_type: true
 Native Overlay Diff: true
Logging Driver: json-file
Cgroup Driver: cgroupfs
Plugins:
 Volume: local
 Network: bridge host macvlan null overlay
 Log: awslogs fluentd gcplogs gelf journald json-file logentries splunk syslog
Swarm: inactive
Runtimes: runc
Default Runtime: runc
Init Binary: docker-init
containerd version: 9b55aab90508bd389d7654c4baf173a981477d55
runc version: 9f9c96235cc97674e935002fc3d78361b696a69e
init version: 949e6fa
Security Options:
 apparmor
 seccomp
  Profile: default
Kernel Version: 4.4.0-116-generic
Operating System: Ubuntu 16.04.4 LTS
OSType: linux
Architecture: x86_64
CPUs: 4
Total Memory: 11.61GiB
Name: peter-pen
ID: P6FS:C76H:WIAO:LCWC:TCHT:JEYB:6W3M:HXYD:S4E2:KTUZ:2T3Q:3GPI
Docker Root Dir: /var/lib/docker
Debug Mode (client): false
Debug Mode (server): false
Registry: https://index.docker.io/v1/
Labels:
Experimental: false
Insecure Registries:
 127.0.0.0/8
Live Restore Enabled: false

WARNING: No swap limit support

Answer 1

This command will stop all docker containers.

sudo killall docker-containerd-shim

This command will remove all docker containers.

sudo docker-compose down

Answer 2

AppArmor (Application Armor) is a Linux security module that protects an operating system and its applications from security threats. To use it, a system administrator associates an AppArmor security profile with each program. Docker expects to find an AppArmor policy loaded and enforced. Check default profiles with:

# sudo apparmor_status

To use docker default profile on a container, run:

$ docker run --rm -it --name test-container --security-opt apparmor=docker-default image-name

You disable it using the commands:

--security-opt apparmor=unconfined

With the docker run commands.

To disable apparmor service, use:

# systemctl stop apparmor && systemctl disable apparmor

For Ubuntu 14. Use:

# service apparmor stop
# update-rc.d -f apparmor remove

It’s recommended to set working profiles for Docker apparmor than disabling it, especially for production setups.

Check this awesome google document on Securing Containers with AppArmor.

https://cloud.google.com/container-optimized-os/docs/how-to/secure-apparmor