It looks like that interface (57) is not on the vlan that subnet one is on.
The interface is on vlan 5019; the subnet is on vlan 5001. Try putting the
interface on the right vlan and then selecting that subnet.

On Wed, Aug 26, 2020 at 5:00 PM Vladimir Grevtsev <
<email address hidden>> wrote:

> Subscribing field-high as this is currently delaying ongoing customer
> delivery.
>
> ** Tags added: field-high
>
> --
> You received this bug notification because you are a member of Canonical
> Field High, which is subscribed to the bug report.
> https://bugs.launchpad.net/bugs/1893135
>
> Title:
>   [2.8] interface link-subnet fails saying "subnet": "None found",
>   however the subnet exists
>
> Status in MAAS:
>   New
>
> Bug description:
>   2020-08-26-21:37:06 root ERROR [localhost] Command failed: maas root
> interface link-subnet 64fxmx 57 subnet=1 mode=auto default_gateway=True
>   2020-08-26-21:37:06 root ERROR [localhost] STDOUT follows:
>   {"subnet": ["None found with id=1.", "This field is required."],
> "default_gateway": ["Subnet is required when default_gateway is True."]}
>
>   However, this subnet ID is valid and exists:
>
>   $ maas root subnet read 1
>   Success.
>   Machine-readable output follows:
>   {
>       "name": "oam",
>       "description": "",
>       "vlan": {
>           "vid": 2101,
>           "mtu": 1500,
>           "dhcp_on": true,
>           "external_dhcp": null,
>           "relay_vlan": null,
>           "fabric_id": 12,
>           "id": 5001,
>           "name": "untagged",
>           "primary_rack": "h633nk",
>           "space": "oam-space",
>           "secondary_rack": "ewqr4n",
>           "fabric": "default",
>           "resource_uri": "/MAAS/api/2.0/vlans/5001/"
>       },
>       "cidr": "10.21.1.0/24",
>       "rdns_mode": 2,
>       "gateway_ip": "10.21.1.254",
>       "dns_servers": [],
>       "allow_dns": true,
>       "allow_proxy": true,
>       "active_discovery": false,
>       "managed": true,
>       "id": 1,
>       "space": "oam-space",
>       "resource_uri": "/MAAS/api/2.0/subnets/1/"
>   }
>
>   $ maas root interface read 64fxmx 57 | pastebinit
>   http://paste.ubuntu.com/p/NGGsqTzD2G/
>
>   $ maas root fabrics read | pastebinit
>   http://paste.ubuntu.com/p/mdHPt35jRb/
>
>   $ maas root subnets read | pastebinit
>   http://paste.ubuntu.com/p/nX9ZnYVgxc/
>
>   $ maas root machine read 64fxmx
>   https://pastebin.canonical.com/p/6FS79HKQhC/
>
>   $ dpkg -l | grep maas
>   ii  maas-cli
>  2.8.1-8567-g.c4825ca06-0ubuntu1~18.04.1         all          MAAS client
> and command-line interface
>   ii  maas-common
> 2.8.1-8567-g.c4825ca06-0ubuntu1~18.04.1         all          MAAS server
> common files
>   ii  maas-dhcp
> 2.8.1-8567-g.c4825ca06-0ubuntu1~18.04.1         all          MAAS DHCP
> server
>   ii  maas-proxy
>  2.8.1-8567-g.c4825ca06-0ubuntu1~18.04.1         all          MAAS Caching
> Proxy
>   ii  maas-rack-controller
>  2.8.1-8567-g.c4825ca06-0ubuntu1~18.04.1         all          Rack
> Controller for MAAS
>   ii  maas-region-api
> 2.8.1-8567-g.c4825ca06-0ubuntu1~18.04.1         all          Region
> controller API service for MAAS
>   ii  maas-region-controller
>  2.8.1-8567-g.c4825ca06-0ubuntu1~18.04.1         all          Region
> Controller for MAAS
>   ii  python3-django-maas
> 2.8.1-8567-g.c4825ca06-0ubuntu1~18.04.1         all          MAAS server
> Django web framework (Python 3)
>   ii  python3-libmaas
> 0.6.1-6-g91e96e9-dirty~bionic-0ubuntu1          all          MAAS asyncio
> client library (Python 3)
>   ii  python3-maas-client
> 2.8.1-8567-g.c4825ca06-0ubuntu1~18.04.1         all          MAAS python
> API client (Python 3)
>   ii  python3-maas-provisioningserver
> 2.8.1-8567-g.c4825ca06-0ubuntu1~18.04.1         all          MAAS server
> provisioning libraries (Python 3)
>
>   Any suggestions what could be wrong will be very appreciated.
>
> To manage notifications about this bug go to:
> https://bugs.launchpad.net/maas/+bug/1893135/+subscriptions
>