missing online CPU information w/ compat REST API

[benoitf]

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

/kind bug

Description

Looking at Compat API
https://docs.docker.com/engine/api/v1.41/#tag/Container/operation/ContainerStats

it says number_cpus = length(cpu_stats.cpu_usage.percpu_usage) or cpu_stats.online_cpus

and

If either precpu_stats.online_cpus or cpu_stats.online_cpus is nil then for compatibility with older daemons the length of the corresponding cpu_usage.percpu_usage array should be used.

but it seems podman is not providing any of percpu_usage or online_cpus

Steps to reproduce the issue:

1. launch a container like httpd

myContainer=$(podman run -d docker.io/library/httpd)

grab cpu_stats

$ curl --silent --unix-socket /Users/benoitf/.local/share/containers/podman/machine/podman-machine-default/podman.sock "http:/v1.41/containers/$myContainer/stats?stream=false"  | jq .cpu_stats
{
  "cpu_usage": {
    "total_usage": 192517000,
    "usage_in_kernelmode": 167090,
    "usage_in_usermode": 192349910
  },
  "system_cpu_usage": 2518699606000,
  "cpu": 0,
  "throttling_data": {
    "periods": 0,
    "throttled_periods": 0,
    "throttled_time": 0
  }
}

or pre_cpu_stats

$ curl --silent --unix-socket /Users/benoitf/.local/share/containers/podman/machine/podman-machine-default/podman.sock "http:/v1.41/containers/$myContainer/stats?stream=false"  | jq .precpu_stats
{
  "cpu_usage": {
    "total_usage": 0,
    "usage_in_kernelmode": 0,
    "usage_in_usermode": 0
  },
  "cpu": 0,
  "throttling_data": {
    "periods": 0,
    "throttled_periods": 0,
    "throttled_time": 0
  }
}

Describe the results you received:

I don't see the number of cpus

Describe the results you expected:

I can get get the number of cpus and compute cpu usage

Additional information you deem important (e.g. issue happens only occasionally):

Output of podman version:

4.2.1 / macOS

Output of podman info:

(paste your output here)

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

(paste your output here)

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

Yes/No

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

[github-actions]

A friendly reminder that this issue had no activity for 30 days.

[github-actions]

A friendly reminder that this issue had no activity for 30 days.

[rhatdan]

This continues to be worked on.

[github-actions]

A friendly reminder that this issue had no activity for 30 days.

[rhatdan]

Getting closer.