MAAS API does not allow changing an fstype or mount_point on LVM volume-groups

[Nick Niehoff]

The MAAS CLI provides methods to set the fstype and mount_point of a normal partition:

maas $PROFILE partition format $SYSTEM_ID $DEVICE_ID $PARTITION_ID fstype=fat32
maas $PROFILE partition mount $SYSTEM_ID $DEVICE_ID $PARTITION_ID mount_point=/boot/efi

However, if this is an LVM logical volume you can't. You can create one with:

maas $PROFILE volume-groups create $SYSTEM_ID partitions=$LVM_PARTITION name=vgtest
maas $PROFILE volume-group create-logical-volume $SYSTEM_ID $VG_ID name=lvtest size=$AVAILABLE_SIZE

But when trying to set the fstype or mount_point with the partition command with the CLI you need a partition_id but the blockdevice is doesn't contain one:

{
  "id_path": null,
  "size": 32103202816,
  "block_size": 4096,
  "tags": [],
  "partition_table_type": null,
  "partitions": [],
  "uuid": "002df611-e116-49da-b6a8-a1069dc35f2f",
  "path": "/dev/disk/by-dname/lvtest",
  "used_size": 0,
  "numa_node": null,
  "used_for": "Unused",
  "filesystem": null,
  "serial": null,
  "id": 413,
  "available_size": 32103202816,
  "storage_pool": null,
  "type": "virtual",
  "name": "vgtest-lvtest",
  "model": null,
  "system_id": "p6fhme",
  "resource_uri": "/MAAS/api/2.0/nodes/p6fhme/blockdevices/413/"
}

I grabbed a tcpdump from UI and it passes null to the WebSocket for the partition_id:

Line-based text data (1 lines)
    {"type":0,"request_id":32,"method":"machine.update_filesystem","params":{"system_id":"p6fhme","block_id":404,"partition_id":null,"fstype":"xfs","mount_point":null,"mount_options":null}}

There doesn't seem to be a way to pass null to either the CLI or the API.

[Jerzy Husakowski (jhusakowski)]

The inconsistency between what's possible via the UI vs API/CLI is unintentional.