Comment 2 for bug 2028156

Context:

* Maas via Debs:
maas-cli/jammy,now 1:3.3.4-13189-g.f88272d1e-0ubuntu1~22.04.1 all [installed]
maas-common/jammy,now 1:3.3.4-13189-g.f88272d1e-0ubuntu1~22.04.1 all [installed]
maas-dhcp/jammy,now 1:3.3.4-13189-g.f88272d1e-0ubuntu1~22.04.1 all [installed]
maas-dns/jammy 1:3.3.4-13189-g.f88272d1e-0ubuntu1~22.04.1 all
maas-proxy/jammy,now 1:3.3.4-13189-g.f88272d1e-0ubuntu1~22.04.1 all [installed]
maas-rack-controller/jammy,now 1:3.3.4-13189-g.f88272d1e-0ubuntu1~22.04.1 all [installed]
maas-region-api/jammy,now 1:3.3.4-13189-g.f88272d1e-0ubuntu1~22.04.1 all [installed,automatic]
maas-region-controller/jammy,now 1:3.3.4-13189-g.f88272d1e-0ubuntu1~22.04.1 all [installed]
maas/jammy,now 1:3.3.4-13189-g.f88272d1e-0ubuntu1~22.04.1 all [installed]

* CLI/UI/API?
Irrelevant, since the result is from a commission script.

* What happens?
Commissioning or enlisting a POWER machine does not fill the machine info, as exposed in the GUI as "Hardware Information" on the "Summary" page or or the "hardware_info" json part of 'maas $USER machine read $MACHINE' :

  "hardware_info": {
    "system_vendor": "Unknown",
    "system_product": "Unknown",
    "system_family": "Unknown",
    "system_version": "Unknown",
    "system_sku": "Unknown",
    "system_serial": "Unknown",
    "cpu_model": "POWER8 (architected), altivec supported",
    "mainboard_vendor": "Unknown",
    "mainboard_product": "Unknown",
    "mainboard_serial": "Unknown",
    "mainboard_version": "Unknown",
    "mainboard_firmware_vendor": "Unknown",
    "mainboard_firmware_date": "Unknown",
    "mainboard_firmware_version": "Unknown",
    "chassis_vendor": "Unknown",
    "chassis_type": "Unknown",
    "chassis_serial": "Unknown",
    "chassis_version": "Unknown"
  },

* How to reproduce?
Long way: Commission a PowerPC machine and look at the results.
Short way:
Execute "/usr/share/maas/machine-resources/ppc64el" on a PowerPC host.
The JSON output of that contains:

        "system": {
            "uuid": "",
            "vendor": "",
            "product": "",
            "family": "",
            "version": "",
            "sku": "",
            "serial": "",
            "type": "physical",
            "firmware": null,
            "chassis": null,
            "motherboard": null
        }

In fact, the issue seems to be with the underlying `lxd/resources` script used, which relies on DMI, which in turn, does not exist on POWER.
LSHW, however works fine, as it uses the POWER device tree.

I merely reported here as Anton Troyanov asked me to on the Discourse.

I attach logs from a machine this happened to plus maas logs of tha time..