ops instance create -t proxmox fails to attach disk on Proxmox VE 9.x — "explicit 'media=cdrom' is required for iso images"

[tmvtmv]

Title

ops instance create -t proxmox fails to attach disk on Proxmox VE 9.x — "explicit 'media=cdrom' is required for iso images"

Environment

• Ops version: 0.1.55
• Host OS: macOS (Apple Silicon), cross-building for --arch=amd64
• Proxmox VE version: 9.2.2
• Target storage: ZFS (zfsdata)

Description

ops image create -t proxmox succeeds and uploads the built image, but it lands in the iso content type on the configured isoStorageName (e.g. local:iso/webapp.iso) rather than as a raw disk image. When ops instance create -t proxmox then tries to attach that file directly as a virtio0 block device, Proxmox rejects it:

{"virtio0":"explicit 'media=cdrom' is required for iso images"}

This appears to be caused by a Proxmox VE behavior change (present since 8.4, still enforced in 9.x) that strictly disallows attaching anything under iso storage content as a normal disk — it must either be mounted as media=cdrom or imported into proper disk/image storage first. Proxmox support has confirmed this is intentional current behavior, not a bug on their end:
https://forum.proxmox.com/threads/possible-regression-in-pve-9-2-3-owner-vm-when-migrating-iso-attached-as-media-disk.184582/

Steps to reproduce

GOOS=linux GOARCH=amd64 go build -o webapp main.go

export API_URL="https://<proxmox-ip>:8006"
export TOKEN_ID="user@pam!tokenid"
export SECRET="..."
export NODE_NAME="gn2"

ops image create webapp -t proxmox -c config.json --arch=amd64
# succeeds, image lands as local:iso/webapp.iso

ops instance create webapp -t proxmox -c config.json
# fails: {"virtio0":"explicit 'media=cdrom' is required for iso images"}

config.json

{
  "RunConfig": {
    "Ports": ["8080"]
  },
  "TargetConfig": {
    "isoStorageName": "local",
    "Arch": "x86_64",
    "Machine": "q35",
    "Sockets": "1",
    "Cores": "1",
    "Memory": "512M",
    "StorageName": "zfsdata",
    "BridgePrefix": "vmbr",
    "Onboot": "0"
  }
}

Expected behavior

ops instance create -t proxmox should either upload the image directly into disk/image storage (bypassing ISO content type entirely), or perform the equivalent of qm importdisk + attach against StorageName automatically, so the resulting VM has a working boot disk without manual intervention.

Actual behavior

The VM is created with network/CPU/memory config intact, but no usable boot disk is attached — it requires manually running (on the Proxmox host):

qm importdisk <vmid> /var/lib/vz/template/iso/webapp.iso zfsdata --format raw
qm set <vmid> --virtio0 zfsdata:vm-<vmid>-disk-0
qm set <vmid> --boot order=virtio0
qm start <vmid>

...after which the unikernel boots correctly.

Related issues

• add proxmox target #1187 — discusses that Proxmox lacked a raw-disk-import API at the time and that this step had to be done manually.