Cloud-Init Block

The cloud-init block configures guest initialization via cloud-init's NoCloud datasource.

Syntax

cloud-init {
    hostname "myvm"
    ssh-key "~/.ssh/id_ed25519.pub"
    user-data "path/to/cloud-config.yaml"
}

All fields are optional.

Fields

hostname

hostname "myvm"

Sets the guest hostname via cloud-init metadata.

ssh-key

ssh-key "~/.ssh/id_ed25519.pub"

Path to an SSH public key file. The key is injected into the cloud-config's authorized_keys for the SSH user. Path is resolved relative to the VMFile directory.

user-data

user-data "cloud-config.yaml"

Path to a raw cloud-config YAML file. When this is set, vmctl passes the file contents directly as user-data without generating its own cloud-config. You are responsible for user creation and SSH setup.

Mutually exclusive with ssh-key in practice - if you provide raw user-data, vmctl won't inject any SSH keys.

Auto-Generated SSH Keys

When a cloud-init block is present but neither ssh-key nor user-data is specified, vmctl automatically:

1. Generates a per-VM Ed25519 keypair.
2. Injects the public key into the cloud-config.
3. Stores both keys in the VM's work directory.

This is the recommended approach for most use cases.