Docker incompatibility: ContainerTop ps_args is not split on whitespace

[leahneukirchen]

Is this a BUG REPORT or FEATURE REQUEST? (leave only one on its own line)

/kind bug

Description

Podman and Docker differ in the interpretation of ps_args for the ContainerTop call, and in the behavior of the "docker top" arguments.

In particular, Podman CLI replaces all spaces in ps_args with ,, breaking some calls.

Podman legacy API passes ps_args as a single argument. Docker API splits on spaces.

Steps to reproduce the issue:

1. `podman top mycontainer ax -o pid,args
2. Notice that ps ax,-o,pid,args gets executed instead.

``

1. Use Podman legacy API with ps_args=ax -o pid,args.
2. Notice that ps 'ax -o pid,args' gets executed (all arguments passed as one).

Describe the results you received:

Note that both calls are invalid for psmisc while Busybox silently ignores them.

Describe the results you expected:

Same behavior as in Docker: get a list of pids and commands.

Output of podman version:

podman version 3.4.2

Output of podman info --debug:

host:
  arch: amd64
  buildahVersion: 1.23.1
  cgroupControllers:
  - cpuset
  - cpu
  - cpuacct
  - blkio
  - memory
  - devices
  - freezer
  - net_cls
  - perf_event
  - net_prio
  - hugetlb
  - pids
  - rdma
  cgroupManager: cgroupfs
  cgroupVersion: v1
  conmon:
    package: 'conmon: /usr/libexec/podman/conmon'
    path: /usr/libexec/podman/conmon
    version: 'conmon version 2.0.30, commit: '
  cpus: 1
  distribution:
    codename: focal
    distribution: ubuntu
    version: "20.04"
  eventLogger: journald
  hostname: runner-obwbw-staging
  idMappings:
    gidmap: null
    uidmap: null
  kernel: 5.4.0-1043-gcp
  linkmode: dynamic
  logDriver: journald
  memFree: 293019648
  memTotal: 3859980288
  ociRuntime:
    name: crun
    package: 'crun: /usr/bin/crun'
    path: /usr/bin/crun
    version: |-
      crun version UNKNOWN
      commit: ea1fe3938eefa14eb707f1d22adff4db670645d6
      spec: 1.0.0
      +SYSTEMD +SELINUX +APPARMOR +CAP +SECCOMP +EBPF +CRIU +YAJL
  os: linux
  remoteSocket:
    exists: true
    path: /run/podman/podman.sock
  security:
    apparmorEnabled: true
    capabilities: CAP_CHOWN,CAP_DAC_OVERRIDE,CAP_FOWNER,CAP_FSETID,CAP_KILL,CAP_NET_BIND_SERVICE,CAP_SETFCAP,CAP_SETGID,CAP_SETPCAP,CAP_SETUID,CAP_SYS_CHROOT
    rootless: false
    seccompEnabled: true
    seccompProfilePath: /usr/share/containers/seccomp.json
    selinuxEnabled: false
  serviceIsRemote: false
  slirp4netns:
    executable: /usr/bin/slirp4netns
    package: 'slirp4netns: /usr/bin/slirp4netns'
    version: |-
      slirp4netns version 1.1.8
      commit: unknown
      libslirp: 4.3.1-git
      SLIRP_CONFIG_VERSION_MAX: 3
      libseccomp: 2.4.3
  swapFree: 0
  swapTotal: 0
  uptime: 2m 38.23s
plugins:
  log:
  - k8s-file
  - none
  - journald
  network:
  - bridge
  - macvlan
  volume:
  - local
registries:
  search:
  - docker.io
  - quay.io
store:
  configFile: /etc/containers/storage.conf
  containerStore:
    number: 2
    paused: 0
    running: 2
    stopped: 0
  graphDriverName: overlay
  graphOptions:
    overlay.mountopt: nodev,metacopy=on
  graphRoot: /var/lib/containers/storage
  graphStatus:
    Backing Filesystem: extfs
    Native Overlay Diff: "false"
    Supports d_type: "true"
    Using metacopy: "true"
  imageStore:
    number: 104
  runRoot: /run/containers/storage
  volumePath: /var/lib/containers/storage/volumes
version:
  APIVersion: 3.4.2
  Built: 0
  BuiltTime: Thu Jan  1 00:00:00 1970
  GitCommit: ""
  GoVersion: go1.16.6
  OsArch: linux/amd64
  Version: 3.4.2

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

podman/unknown,now 100:3.4.2-1 amd64 [installed]

Have you tested with the latest version of Podman and have you checked the Podman Troubleshooting Guide? (https://github.com/containers/podman/blob/master/troubleshooting.md)

Yes

Additional environment details (AWS, VirtualBox, physical, etc.):

Not relevant to the issue.

Workaround:

Using -eopid,args as a workaround for now.

[vrothberg]

Thanks for reaching out, @leahneukirchen.

Out of curiosity. What do you refer to with "Podman legacy API"?

[leahneukirchen]

I mean, speaking Docker API to Podman (not libpod api).