[2.0b7, API/CLI] allows you to add machines with power_type and no power_parameters

This is very easy to recreate:

https://pastebin.canonical.com/160427/

All the nodes of the same power type end up on a single controller. To workaround I am having to first save them with APU which breaks that bond, then going back to IPMI to edit. Without doing that, it ends up editing a single entry shared amount 70+ or so of the IPMI ones and 10+ of the AMT ones.

Clarification.. one power controller shared by IPMI nodes and one shared controller for AMT nodes.

Here's two nodes that were created without power parameters, you can see they end up with the same BMC:

>>> suangi.bmc
<BMC: 92 (192.168.224.200:type=STICKY)>
>>> prunus.bmc
<BMC: 92 (192.168.224.200:type=STICKY)>
>>> bmc = prunus.bmc
>>> bmc.power_type
'ipmi'
>>> bmc.node_set.count()
47

You can see this bmc has 47 nodes attached to it.

When we go to set the power parameters on the nodes, it affects all the nodes.

To work around this I had to do this from the maas-region-admin shell.

>>> for node in bmc.node_set.all():
... node.bmc = BMC(power_type='ipmi')
... node.bmc.save()
... node.save()

Followed by this:
>>> for node in Node.objects.all():
... if node.power_type is "":
... node.power_type = 'ipmi'
... node.save()

I recreated this from the GUI. Attaching screenshots.. Basically doing the equivalent of the maas CLI commands, specifying the power type and no parameters.

After setting the BMCs to seperate objects via the admin shell, they were switched back to having the same BMC object at some point, so our work around did not work and we are stuck.

I ran the following commands (see pastebin) for updating the power parameters and they ended up under the shared controller again:

For example:
ubuntu@maas2-production:~/lmic/fix$ maas root machine update 4y3hgt power_parameters_power_driver=LAN_2_0 power_parameters_power_address=192.168.224.45 power_parameters_power_user=admin power_parameters_power_pass=insecure
Success.
Machine-readable output follows:
{
    "address_ttl": null,
...
}

Here are all the commands:

https://pastebin.canonical.com/160588/

Here's screen shot attached.

Note that the warning message says 63 nodes but initially that message had said 64 nodes (I applied the workaround described earlier to 1 node).

Per Andres, the power parameters need to be specified at creation time as in example below.

I deleted gytrash entry which had the problem and recreated the node with:

$ maas root machines create architecture=amd64 subarchitecture=generic min_hwe_kernel=hwe-t mac_addresses=2c:59:e5:47:2e:84 domain=oil hostname=gytrash power_parameters_power_driver=LAN_2_0 power_parameters_power_address=192.168.224.45 power_parameters_power_user=admin power_parameters_power_pass=insecure power_type=ipmi
Success.
Machine-readable output follows:
{
    "virtualblockdevice_set": [],
    "owner_data": {},
    "architecture": "amd64/generic",
    "distro_series": "",
    "status": 1,
    "status_name": "Commissioning",
    "storage": 0.0,
    "physicalblockdevice_set": [],
    "cpu_count": 0,
    "fqdn": "gytrash.oil",
    "address_ttl": null,
    "memory": 0,
    "special_filesystems": [],
    "hostname": "gytrash",
    "interface_set": [
        {
            "children": [],
            "discovered": null,
            "enabled": true,
            "id": 1041,
            "parents": [],
            "tags": [],
            "mac_address": "2c:59:e5:47:2e:84",
            "vlan": {
                "external_dhcp": null,
                "secondary_rack": null,
                "dhcp_on": true,
                "id": 5001,
                "vid": 0,
                "mtu": 1500,
                "name": "untagged",
                "resource_uri": "/MAAS/api/2.0/vlans/5001/",
                "primary_rack": "4y3h7n",
                "fabric": "fabric-0"
            },
            "params": "",
            "effective_mtu": 1500,
            "type": "physical",
            "name": "eth0",
            "resource_uri": "/MAAS/api/2.0/nodes/4y3hxd/interfaces/1041/",
            "links": []
        }
    ],
    "status_action": "start commissioning",
    "disable_ipv4": false,
    "owner": "root",
    "node_type": 0,
    "min_hwe_kernel": "hwe-t",
    "power_type": "ipmi",
    "zone": {
        "description": "",
        "name": "default",
        "resource_uri": "/MAAS/api/2.0/zones/default/",
        "id": 1
    },
    "domain": {
        "ttl": null,
        "id": 0,
        "resource_record_count": 24,
        "name": "oil",
        "resource_uri": "/MAAS/api/2.0/domains/0/",
        "authoritative": true
    },
    "status_message": "(root)",
    "osystem": "",
    "node_type_name": "Machine",
    "hwe_kernel": "",
    "system_id": "4y3hxd",
    "ip_addresses": [],
    "tag_names": [],
    "boot_disk": null,
    "swap_size": null,
    "power_state": "unknown",
    "netboot": true,
    "resource_uri": "/MAAS/api/2.0/machines/4y3hxd/",
    "boot_interface": {
        "children": [],
        "discovered": null,
        "enabled": true,
        "id": 1041,
        "parents": [],
        "tags": [],
        "mac_address": "2c:59:e5:47:2e:84",
        "vlan": {
            "external_dhcp": null,
            "secondary_rack": null,
            "dhcp_on": true,
            "id": 5001,
            "vid": 0,
            "mtu": 1500,
            "name": "untagged",
            "resource_uri": "/MAAS/api/2.0/vlans/5001/",
            "primary_rack": "4y3h7n",
            "fabric": "fabric...