[pkg-go] Bug#968207: podman: Breaks docker

[Jan Hudec]

Package: podman
Version: 2.0.4+dfsg2-1
Severity: critical
Justification: breaks unrelated software

Dear Maintainer,

   * What led up to the situation?

Installing podman or upgrading from 2.0.2+dfsg1-3 to 2.0.3+dfsg1-1
(transcript below, re-testing with 2.0.4

   * What was the outcome of this action?

docker stopped working, in two ways:

 - Users in docker group are no longer able to run docker (permission
   denied).
 - The configured images and containers are no longer available. If they were
   running, they still are, but cannot be controlled any more.

This is because /var/run/docker.sock gets unconditionally redirected to
/run/podman/podman.sock.

   * What outcome did you expect instead?

Since docker.io is not mentioned in Breaks: and since the packages are not
fundamentally inconsistent, I expect them to work together. This is needed at
least to smoothly transition all configured workloads from one to the other.

   * What exactly did you do (or not do) that was effective (or
     ineffective)?

Workaround is:

$ sudo dpkg-divert --local --rename --add /usr/lib/tmpfiles.d/podman.conf
$ sudo rm /run/docker.sock
$ sudo systemctl restart docker

Disadvantage is that this restarts any running containers, which might be
undesired at the time.

I suggest creating a podman-docker-compat or similar package with that link,
and also linking /usr/bin/docker to /usr/bin/podman, and breaking docker.io.

-- Transcript:

$ docker ps -a
CONTAINER ID        IMAGE                     COMMAND                  CREATED             STATUS                           PORTS               NAMES
7d5e9d7bf3fd        mbsync:latest             "mbsync -a -q"           21 months ago       Exited (1) 3 minutes ago                             mbsync
$ sudo aptitude install podman  
The following NEW packages will be installed:
  conmon{a} containernetworking-plugins{a} golang-github-containers-common{a} podman slirp4netns{a} 
0 packages upgraded, 5 newly installed, 0 to remove and 0 not upgraded.
Need to get 19.2 MB of archives. After unpacking 93.8 MB will be used.
Do you want to continue? [Y/n/?] 
[…snip install log…]
$ docker ps -a                
Got permission denied while trying to connect to the Docker daemon socket at unix:///var/run/docker.sock: Get "http://%2Fvar%2Frun%2Fdocker.sock/v1.40/containers/json?all=1": dial unix /var/run/docker.sock: connect: permission denied
$ echo $?
1
$ ls -l /run/docker.*         
-rw-r--r-- 1 root root  4 Aug 10 07:01 /run/docker.pid
lrwxrwxrwx 1 root root 23 Aug 10 18:54 /run/docker.sock -> /run/podman/podman.sock=

-- System Information:
Debian Release: bullseye/sid
  APT prefers testing
  APT policy: (990, 'testing'), (500, 'oldstable-updates'), (500, 'unstable'), (500, 'oldstable'), (1, 'experimental')
Architecture: amd64 (x86_64)
Foreign Architectures: x32, i386

Kernel: Linux 5.7.0-2-amd64 (SMP w/8 CPU threads)
Locale: LANG=en_GB.UTF-8, LC_CTYPE=en_GB.UTF-8 (charmap=UTF-8), LANGUAGE=en_GB:en_US
Shell: /bin/sh linked to /bin/dash
Init: systemd (via /run/systemd/system)
LSM: AppArmor: enabled

Versions of packages podman depends on:
ii  conmon                           2.0.18-1
ii  containernetworking-plugins      0.8.6-2
ii  crun                             0.14.1+dfsg-1
ii  golang-github-containers-common  0.14.6+ds1-1
ii  init-system-helpers              1.58
ii  libc6                            2.31-2
ii  libdevmapper1.02.1               2:1.02.171-2
ii  libgpgme11                       1.13.1-9
ii  libseccomp2                      2.4.3-1+b1
ii  runc                             1.0.0~rc10+dfsg2-1

Versions of packages podman recommends:
ii  buildah         1.15.0-6
ii  fuse-overlayfs  1.0.0-1
ii  slirp4netns     1.0.1-1
ii  tini            0.18.0-1+b1
ii  uidmap          1:4.8.1-1

Versions of packages podman suggests:
ii  containers-storage  1.21.2+dfsg1-1

-- no debconf information