podman attach does not exit when the container stops

[faulesocke]

/kind bug

Description
When attaching to a self-quitting container (for example one with "CMD sleep 10") with podman attach <id>, the podman attach process does not exit once the container stops. This was different in the past and is unexpected. I use attach to see logs and wait for the container to finish.

Steps to reproduce the issue:

podman build -t test -f - << EOF
FROM whatever
CMD sleep 100
EOF

podman run -d --name foo test

3. attach to the container and wait for it to exit:

podman attach foo

Describe the results you received:
podman attach never returns

Describe the results you expected:
podman attach returns after approx. 10 seconds

Output of podman version:

% podman version                                                                                                                     :(
Version:      2.1.1
API Version:  2.0.0
Go Version:   go1.15.2
Built:        Thu Jan  1 01:00:00 1970
OS/Arch:      linux/amd64

Output of podman info --debug:

host:
  arch: amd64
  buildahVersion: 1.16.1
  cgroupManager: cgroupfs
  cgroupVersion: v1
  conmon:
    package: Unknown
    path: /usr/libexec/podman/conmon
    version: 'conmon version 2.0.21, commit: unknown'
  cpus: 4
  distribution:
    distribution: '"void"'
    version: unknown
  eventLogger: file
  hostname: Sockpad
  idMappings:
    gidmap:
    - container_id: 0
      host_id: 1000
      size: 1
    - container_id: 1
      host_id: 100000
      size: 65536
    uidmap:
    - container_id: 0
      host_id: 1000
      size: 1
    - container_id: 1
      host_id: 100000
      size: 65536
  kernel: 4.19.142+
  linkmode: dynamic
  memFree: 1153695744
  memTotal: 16384040960
  ociRuntime:
    name: runc
    package: Unknown
    path: /usr/bin/runc
    version: 'runc version spec: 1.0.2-dev'
  os: linux
  remoteSocket:
    path: /tmp/run-1000/podman/podman.sock
  rootless: true
  slirp4netns:
    executable: /bin/slirp4netns
    package: Unknown
    version: |-
      slirp4netns version 1.1.4
      commit: b66ffa8e262507e37fca689822d23430f3357fe8
      libslirp: 4.3.1
      SLIRP_CONFIG_VERSION_MAX: 3
  swapFree: 0
  swapTotal: 0
  uptime: 152h 31m 11.62s (Approximately 6.33 days)
registries: {}
store:
  configFile: /home/socke/.config/containers/storage.conf
  containerStore:
    number: 5
    paused: 0
    running: 2
    stopped: 3
  graphDriverName: overlay
  graphOptions:
    overlay.mount_program:
      Executable: /bin/fuse-overlayfs
      Package: Unknown
      Version: |-
        fusermount3 version: 3.10.0
        fuse-overlayfs: version 1.1.0
        FUSE library version 3.10.0
        using FUSE kernel interface version 7.31
  graphRoot: /home/socke/.local/share/containers/storage
  graphStatus:
    Backing Filesystem: extfs
    Native Overlay Diff: "false"
    Supports d_type: "true"
    Using metacopy: "false"
  imageStore:
    number: 26
  runRoot: /tmp/run-1000/containers
  volumePath: /home/socke/.local/share/containers/storage/volumes
version:
  APIVersion: 2.0.0
  Built: 0
  BuiltTime: Thu Jan  1 01:00:00 1970
  GitCommit: ""
  GoVersion: go1.15.2
  OsArch: linux/amd64
  Version: 2.1.1

Package info (e.g. output of rpm -q podman or apt list podman):

% xq podman
pkgver: podman-2.1.1_1
short_desc: Simple management tool for containers and images
architecture: x86_64
filename-sha256: 4644867b3b093c0f2fbc3c95b70dffb44176bb6b14dfba44e43f10128e4b1d65
filename-size: 20MB
homepage: https://podman.io/
installed_size: 48MB
license: Apache-2.0
maintainer: Cameron Nemo <[email protected]>
pkgname: podman
repository: https://alpha.de.repo.voidlinux.org/current
run_depends:
	runc>=0
	conmon>=0
	cni-plugins>=0
	slirp4netns>=0
	containers.image>=0
	glibc>=2.29_1
	libgpgme>=1.12.0_2
	libassuan>=2.0.1_1
	libgpg-error>=1.6_1
	libseccomp>=2.0.0_1
	device-mapper>=2.02.110_1
shlib-requires:
	libpthread.so.0
	libgpgme.so.11
	libassuan.so.0
	libgpg-error.so.0
	libseccomp.so.2
	librt.so.1
	libdevmapper.so.1.02
	libc.so.6
source-revisions: podman:b990889240
depends:
	runc>=0
	conmon>=0
	cni-plugins>=0
	slirp4netns>=0
	containers.image>=0
	glibc>=2.29_1
	libgpgme>=1.12.0_2
	libassuan>=2.0.1_1
	libgpg-error>=1.6_1
	libseccomp>=2.0.0_1
	device-mapper>=2.02.110_1

Have you tested with the latest version of Podman and have you checked the Podman Troubleshooting Guide?

No

[Luap99]

I'm not sure why it doesn't work but it seems to work if you add the -t option to the run command, e.g. podman run -d -t --name foo test.

[rhatdan]

@mheon Thoughts on this one?

[mheon]

I'll take a look, see if I can reproduce

[mheon]

Works fine over here. Your Dockerfile looks suspicious - you say you expect the container to exit after 10 seconds, but you have a sleep 100 in there, so I'd expect it would take 100 seconds instead...

[mheon]

Ahhh, nevermind, I see that it does reproduce when -t is not used. Interesting.

[mheon]

This is very interesting. The attach socket is completely removed, Conmon is dead, but Podman is still listening on it.

[mheon]

Got it - #8175