Advanced production model

Ubuntu Core docs
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Here we provide an overview of the advanced production model:

  • You define your own device type and hence have one or more of:
  • You curate your own store of snaps, a Dedicated Snap Store
  • You want Update Control, to decide when updates are published to devices you have created

They provide all the functionality and control required to manage your device ecosystem.

image

Steps

The high level steps for this production model are:

  1. Contact your Canonical representative to:
    • Create you a Brand Account
    • Create your Dedicated Snap Store associated with this account
    • Provide instructions on tools and process needed for manufacturing
  2. Create your gadget snap and publish it in your store
  3. Create the extra snaps needed for your device’s base functionality and publish them in your store
  4. Create a model assertion and sign it using a key you have registered with the store
  5. Create your device image (including your extra snaps) using the signed model assertion
  6. Flash your image to your devices at your production facility / factory
  7. Perform an initial boot of the device in the factory to get a signed serial assertion from a Serial Vault
  8. Distribute your devices to the consumer

Let’s take a closer look at some these steps.

Create your gadget snap

The reference section contains detailed information about the format of a gadget snap: Gadget Snap.

Of particular importance is the prepare-device hook which must contain the details how to contact your Serial Vault (see later section).

Create the extra snaps

Once your snap is working as expected, publish it to the dedicated Snap Store. These snaps will only be available to devices whose model assertion specifies your brand and store.

Detailed information about building snap packages can be found on snapcraft.io.

Create a model assertion

Steps for creating a signed model assertion are provided here.

Let’s look at a sample of the JSON file used as input when creating a model assertion for a fictional device, the “Device 1”, made by the brand “ACME Corp”. The host architecture is armhf. The image will be populated with the gadget and kernel snaps that support this hardware, the core snap, and two extra snaps required for the device to function correctly, “acme-dashboard” and “acme-control-plane”. Note that the authority-id and brand-id match the account-id defined for the ACME Corp account.

{
  "type": "model",
  "authority-id": "acme",
  "brand-id": "acme",
  "store": "abcdef123456789"
  "series": "16",
  "model": "acme-device-1",
  "architecture": "armhf",
  "gadget": "device-1",
  "kernel": "device-1-kernel",
  "required-snaps": ["acme-dashboard", "acme-control-plane"],
  "timestamp": "2016-12-01T12:00:00+00:00"
}

As noted in the image building documentation, you sign it with your registered key, which produces your signed model assertion file, which is used in the next step to build your image.

Build the image

Steps for creating an image from the signed model assertion are found here.

Factory flash you device

The process requires a serial assertion signed by your brand account. To support you in managing you keys and signing the serial assertion during the production process Canonical have developed an open source tool called the Serial Vault.

The Serial Vault allows you to make sure the device leaves production ready to communicate with the dedicated Snap Store and gives you confidence that only devices produced by you have access to your snaps.

Distribute your devices

When your devices are in the field and operational they will communicate with your dedicated Snap Store to identify when updates are available or to install snaps that the user wants.