Build your own Ubuntu Core image

[degville]

Build your own Ubuntu Core image

Ready to try out Ubuntu Core?

This tutorial will guide you through the steps required to create your own Ubuntu Core image, with your own selection of snaps, and install it on a Raspberry Pi.

Here’s what you’ll need for the tutorial

• a basic understanding of Linux and the command line
• a Raspberry Pi 4 Model B (any model)
  • 4GB+ microSD card
  • keyboard and display (for setup only)
  • Ethernet or wireless network connectivity
• Ubuntu 20.04 LTS (Focal Fossa) or later
• 10GB of free storage space
• a microSD card reader
• access to the internet

The above requirements are specific to this tutorial. Other distributions can be used, and other platforms are supported. See Supported platforms for details.

Step-by-step guide

Here’s an overview of the steps required with links to our separate tutorials that deal with each individual step:

• 1. Create an Ubuntu One account
  • 1. Create the account online
  • 2. Retrieve your developer account id
• 2. Create the model assertion
  • 1. Download a model assertion
  • 2. Edit the model assertion
  • 2.1 authority-id and brand-id
  • 2.2 timestamp
  • 2.3 snaps
  • 2.4 my-model.json
  • 3. A complete model assertion
• 3. Sign the model assertion
  • 1. Create a key
  • 2. Register the key
  • 3. Sign the model
• 4. Build and write the image
  • 1. Compile the image
  • 2. Write the image
• 5. Boot the image
  • 1. Boot Ubuntu Core
  • 1.1 Configure a network connection
  • 2. Connect to the device

[rpjday1]

What’s with the timestamp example in section 4.2 ending in “0Z”? Is this some weird but valid variation?

[degville]

I think it’s the UTC offset from the timestamp in the model. Not sure how that’s been generated, but it’s accepted.