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PVE NoCloud bootstrap for the live ISO

The routerd live ISO is built from an Ubuntu debootstrap root filesystem and does not install the full cloud-init package. For Proxmox VE lab nodes, the image supports the small part of NoCloud that is needed before routerd starts: it reads hostname, routerd.config_url, and routerd.config_sha256 from user-data on a cidata/CIDATA config drive.

This keeps the live ISO small while still letting multiple VMs boot from the same ISO, appear as distinct hosts over SSH and in PVE validation logs, and pull their full routerd config from HTTP or object storage.

user-data​

Create a PVE snippet with a top-level hostname field and an optional routerd config pointer:

#cloud-config
hostname: pve-rt07
routerd:
  config_url: http://10.0.0.10/routerd/pve-rt07/router.yaml
  config_sha256: 0123456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef
ssh_authorized_keys:
  - ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAA... admin@example

Attach it as the VM's cloud-init user-data:

qm set 169 --ide2 local:iso/routerd-live.iso,media=cdrom
qm set 169 --cicustom user=local:snippets/routerd-pve-rt07.yaml
qm set 169 --boot order=ide2
qm reboot 169

At boot, the live setup service:

  1. Applies hostname from NoCloud user-data.
  2. Regenerates SSH host keys so every VM has a distinct host identity.
  3. Installs ssh_authorized_keys into /root/.ssh/authorized_keys and enables ssh.service.
  4. Tries a ROUTERD_CONFIG config disk first.
  5. If no config disk is present, fetches routerd.config_url with curl.
  6. Verifies routerd.config_sha256 when present.
  7. Installs the fetched router.yaml or extracts a supported config bundle.
  8. Falls back to the last validated cache, then to the built-in sample config when no external config is available.

Supported bundle URLs currently end in .tar.zst, .tzst, .tar.gz, .tgz, or .tar. Bundles must contain router.yaml at the archive root. Optional secrets/ and metadata.json entries are installed under /usr/local/etc/routerd/.

After a successful fetch and checksum verification, the installed router.yaml is cached under /var/lib/routerd/validated-config/router.yaml. If a later boot cannot fetch routerd.config_url, the live ISO restores that validated cache.

Scope​

This is intentionally not a full cloud-init implementation. The live ISO only uses NoCloud for early hostname identity, root SSH authorized keys, and routerd config bootstrap. It does not run cloud-init modules or apply network, user, or package configuration from user-data.

For richer bootstrap behavior, keep using routerd configuration media or install Ubuntu Server to disk and manage normal cloud-init there.