Podman new rest API for stats does not report an error when in rootless mode on cgroupv1 system

[Katerina Koukiou]

root@ubuntu:~# lsb_release -rd
Description: Ubuntu 21.04
Release: 21.04

root@ubuntu:~# dpkg -s podman | grep Version
Version: 3.0.1+dfsg1-1ubuntu1

I am running all the cmds below as admin non root user.

There is this running container under admin user:

admin@ubuntu:~$ podman ps --all
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
39499f3da7a1 busybox:latest sh 6 minutes ago Up 6 minutes ago swamped-crate

Using the old API (deprecated) to list stats for this container I (as expected get an error)

admin@ubuntu:~$ curl --unix-socket /run/user/1000/podman/podman.sock http://d/v1.24/libpod/containers/39499f3da7a1/stats
{"cause":"no support for CGroups V1 in rootless environments","message":"failed to obtain Container 39499f3da7a1 stats: unable to load cgroup at /user.slice/user-1000.slice/[e-mail]/app.slice/podman.service/39499f3da7a16ab5c76856d5b373a61361885172ca773c5c4b8b4a4abec89f85: no support for CGroups V1 in rootless environments","response":500}

Using the new API (recommended) to list stats, there is not any error and of course not stats.

admin@ubuntu:~$ curl --unix-socket /run/user/1000/podman/podman.sock http://d/v1.24/libpod/containers/stats
{"Error":{},"Stats":null}

The expected result if that the new stats API will also print an error like the old one.

admin@ubuntu:~$ podman info
host:
  arch: amd64
  buildahVersion: 1.19.6
  cgroupManager: cgroupfs
  cgroupVersion: v1
  conmon:
    package: 'conmon: /usr/bin/conmon'
    path: /usr/bin/conmon
    version: 'conmon version 2.0.25, commit: unknown'
  cpus: 1
  distribution:
    distribution: ubuntu
    version: "21.04"
  eventLogger: journald
  hostname: ubuntu
  idMappings:
    gidmap:
    - container_id: 0
      host_id: 1001
      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: 5.11.0-34-generic
  linkmode: dynamic
  memFree: 416464896
  memTotal: 1149898752
  ociRuntime:
    name: runc
    package: 'runc: /usr/sbin/runc'
    path: /usr/sbin/runc
    version: |-
      runc version 1.0.0~rc95-0ubuntu1~21.04.2
      spec: 1.0.2-dev
      go: go1.16.2
      libseccomp: 2.5.1
  os: linux
  remoteSocket:
    exists: true
    path: /run/user/1000/podman/podman.sock
  security:
    apparmorEnabled: false
    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: true
    seccompEnabled: true
    selinuxEnabled: false
  slirp4netns:
    executable: /usr/bin/slirp4netns
    package: 'slirp4netns: /usr/bin/slirp4netns'
    version: |-
      slirp4netns version 1.0.1
      commit: 6a7b16babc95b6a3056b33fb45b74a6f62262dd4
      libslirp: 4.4.0
  swapFree: 0
  swapTotal: 0
  uptime: 7m 49.13s
registries: {}
store:
  configFile: /home/admin/.config/containers/storage.conf
  containerStore:
    number: 1
    paused: 0
    running: 1
    stopped: 0
  graphDriverName: overlay
  graphOptions:
    overlay.mount_program:
      Executable: /usr/bin/fuse-overlayfs
      Package: 'fuse-overlayfs: /usr/bin/fuse-overlayfs'
      Version: |-
        fusermount3 version: 3.10.2
        fuse-overlayfs: version 1.4
        FUSE library version 3.10.2
        using FUSE kernel interface version 7.31
  graphRoot: /home/admin/.local/share/containers/storage
  graphStatus:
    Backing Filesystem: extfs
    Native Overlay Diff: "false"
    Supports d_type: "true"
    Using metacopy: "false"
  imageStore:
    number: 3
  runRoot: /run/user/1000/containers
  volumePath: /home/admin/.local/share/containers/storage/volumes
version:
  APIVersion: 3.0.0
  Built: 0
  BuiltTime: Thu Jan 1 00:00:00 1970
  GitCommit: ""
  GoVersion: go1.16
  OsArch: linux/amd64
  Version: 3.0.1