feat: cloud init disk resource

[lsjostro]

This new resource creates/manage cloud-init configdrive as ISO-files. It generates a cloud-init iso and uploads it to proxmox. This enables a wider/more advanced support for cloud-init then Proxmox currently supports.

To use the generated cloud-init iso, VMs just need to define a disk block with type=ide, media=cdrom and volume=proxmox_cloud_init_disk.<my_ci_resource>.id parameters.

Need to add docs before it's ready to be merged. But a first review would be helpful.

example:

resource "proxmox_cloud_init_disk" "ci" {
  name      = var.name
  pve_node  = var.pve_node
  storage   = "cephfs"

  meta_data = <<EOF
instance-id: ${var.name}
local-hostname: ${var.name}
EOF

  user_data = <<EOF
#cloud-config
users:
  - name: foo
    sudo: ALL=(ALL) NOPASSWD:ALL
EOF
  
  network_config = <<EOF
...your network config...
EOF
}

resource "proxmox_vm_qemu" "foo" {
....
  disk {
    type    = "ide"
    media   = "cdrom"
    storage = "cephfs"
    volume  = proxmox_cloud_init_disk.ci.id
    size    = proxmox_cloud_init_disk.ci.size
  }
...
}

[lsjostro]

added docs now, so I think it's ready for review!

[mleone87]

great contribution, I left some comments otherwise LGTM

[lsjostro]

before merge we prob need the fix in the go-api as well. Telmate/proxmox-api-go#254

[lsjostro]

I guess this can be merged then. Will not 100% work in all cases until we get the new reworked disk handling in the go API into this project.

[paraglade]

Note: this update requires Datastore.AllocateTemplate permssions
from the Proxmox user manual:
https://pve.proxmox.com/pve-docs/chapter-pveum.html#_privileges:~:text=Datastore.AllocateTemplate%3A%20allocate/upload%20templates%20and%20ISO%20images

Datastore.AllocateTemplate: allocate/upload templates and ISO images