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Instance

MltInstance declares a Multipass Ubuntu VM. At deploy time the engine calls multipass launch with the resolved props, and at destroy time it calls multipass delete --purge.

Type: Multipass::Compute::Instance
Import: @cdk-x/multipass

Create-only resource

All props are create-only. Once a VM is launched, the engine will not call update. To change any prop, destroy the VM and redeploy.

Props

Prop Type Required Description
name string ✅ Name of the VM. Must be unique within the Multipass instance. Passed as --name to multipass launch.
image string — Ubuntu image alias or release (e.g. jammy, 22.04, lts). Defaults to the latest LTS if omitted.
cpus number — Number of virtual CPUs. Passed as --cpus.
memory string — Memory allocation (e.g. 2G, 512M). Passed as --memory.
disk string — Disk size (e.g. 20G). Passed as --disk.
bridged boolean — Add a bridged network interface. Equivalent to --bridged.
timeout number — Launch timeout in seconds. Passed as --timeout.
networks InstanceNetwork[] — Host network interfaces to attach at launch time. Each entry maps to a --network argument.
mounts InstanceMount[] — Host-to-guest directory mounts. Each entry maps to a --mount argument.
cloudInit string — Cloud-init user-data string passed to the VM at launch time. Passed as --cloud-init.

Attribute getters

These resolve to runtime values after the VM is created:

Getter Type Resolves to
attrIpAddress IResolvable The VM's IP address, as returned by multipass info.
attrSshUser IResolvable The SSH user inside the VM (typically ubuntu).

Use these to pass VM details to other constructs:

const vm = new MltInstance(stack, 'Dev', { name: 'dev', image: 'jammy' });

// e.g. pass the IP to another resource
someOtherResource.hostIp = vm.attrIpAddress;

Basic example

.cdkxrc.ts
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import { App, Stack } from '@cdk-x/core';
import { MltInstance, MltProvider } from '@cdk-x/multipass';

const app = new App();
const stack = new Stack(app, 'DevVMs', { provider: new MltProvider() });

new MltInstance(stack, 'Dev', {
  name: 'dev',
  image: 'jammy',
  cpus: 4,
  memory: '4G',
  disk: '20G',
});

app.synth();

Translates to:

multipass launch jammy --name dev --cpus 4 --memory 4G --disk 20G

Example with network, mount, and cloud-init

Networks and mounts are plain inline objects — no separate constructs needed:

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import { App, Stack } from '@cdk-x/core';
import { MltInstance, MltProvider } from '@cdk-x/multipass';

const app = new App();
const stack = new Stack(app, 'DevVMs', { provider: new MltProvider() });

new MltInstance(stack, 'Dev', {
  name: 'dev',
  image: 'jammy',
  cpus: 4,
  memory: '4G',
  disk: '20G',
  networks: [
    { name: 'bridge', mode: 'auto' }, // (1)!
  ],
  mounts: [
    { source: '/Users/me/code', target: '/home/ubuntu/code' }, // (2)!
  ],
  cloudInit: '#cloud-config\npackages:\n  - git\n  - curl\n', // (3)!
});

app.synth();
  1. Attaches the host interface named bridge in automatic configuration mode. Run multipass networks to list interfaces available on your machine.
  2. Mounts /Users/me/code on the host at /home/ubuntu/code inside the VM.
  3. Passed verbatim to multipass launch --cloud-init. Must be a valid cloud-init YAML string.

Translates to:

multipass launch jammy \
  --name dev \
  --cpus 4 --memory 4G --disk 20G \
  --network bridge,mode=auto \
  --mount /Users/me/code:/home/ubuntu/code \
  --cloud-init <tmpfile>

See also