Try pre-built images

degville · 2021-10-01T13:23:37.046Z

NOTE TO EDITORS

This page of documentation has moved to:
https://documentation.ubuntu.com/core/tutorials/try-pre-built-images

It will continue to be updated and supported only from the new location. We also welcome community contributions.

To suggest improvements, or to notify us of an issue, please use the Give feedback button on the new page. Thank you!

Ubuntu Core runs on a variety of hardware, and pre-built images are available for amd64 and ARM platforms (among others). These images can also be installed on a virtual machine.

Pre-built images are ideal for exploration and experimentation, but they are not intended for deployment or use at scale. They include snaps to provide an onboarding and evaluation experience, alongside an SSH connection, and these are unlikely to be required in your own Ubuntu Core deployment.

Ubuntu Core has instead been designed to facilitate creating, deploying, and managing secure custom images running on your hardware.

See Supported testing platforms for links to image downloads, ant to learn how to create your own custom image, read our Build an image guide.


Install Ubuntu Core on a VM Try Ubuntu Core without any specific hardware from within a virtual machine	Try a pre-built image Install a pre-built Ubuntu Core image in a supported testing platform

thepenguinmaster · 2021-10-12T00:05:02.310Z

Thank you for this post. I did notice a few problems with the instructions. The qemu command is provided, but there appears to be a duplicate line with part of the word “user” missing on line 2. Also the ubuntu core image is said to be named uc.img, but the command attempts to use an image of pc.img.

Also the text below the SSH command is copied form the previous instruction and does not make much sense.

Some of the corrections may help others in the future.

degville · 2021-10-12T09:05:27.038Z

Hello - thanks so much for taking the trouble to let us know about those errors. I’ve fixed them, and sorry they made their way into the tutorial unchecked. They looked like the pasted detritus from a broken editing session.

rpjday1 · 2022-01-26T11:59:36.856Z

Most of this is already covered in the earlier Quick Start page.

degville · 2022-01-26T12:15:28.134Z

Yes, this is true. We’re in the process of moving these docs to use the Diátaxis framework (https://diataxis.fr/) and these tutorials need to be updated and expanded. It won’t remove the duplication, but will make each rigorously conceived, implemented and tested, targetting specific platforms.

This is high on the priority list. There’s more on our tutorial strategy on the Ubuntu blog: https://ubuntu.com/blog/the-idea-of-a-tutorial

johnamcclure · 2022-06-17T16:15:46.066Z

I installed core 22 on a RPi. I yes to the fingerprint and then it asks for a password. Does not accept my ONE password. same if I reboot the system an]d ssh in again, this time direct, still asks for a password. Is there a default?

degville · 2022-06-20T09:30:12.104Z

Hello!

To connect to your Pi, you will need to make sure 1) you have a public SSH key registered with your Ubuntu One account, and 2) the local ssh command uses the associated private key (a password isn’t used as the connection is authenticated through this key pair).

There’s a little more information on how to connect here:

First steps with Ubuntu Core Ubuntu Core docs

The main difference between a classic Ubuntu installation and Ubuntu Core is that Ubuntu Core’s system configuration, package management, and update control is governed entirely by snapd, the snap daemon. Snap features are explained comprehensively in the Snap documentation, but we’ll cover some basic operations below: You can list which snaps are installed on your Ubuntu Core system with snap list: $ snap list Name Version Rev Tracking Publisher Notes core22 2023…

The complete process, including key generation is under the “Generating an SSH key pair” heading in this tutorial:

How to install Ubuntu Core on your Raspberry Pi Tutorials

Key Value Summary A complete guide to installing the latest version of Ubuntu Core on your Raspberry Pi 4, 3 or 2. Categories iot, raspberrypi Difficulty 2 Author Canonical Web Team webteam@canonical.com Overview Duration: 2:00 In this tutorial, we will walk you through the process of installing Ubuntu Core on a Raspberry Pi, connecting it to the internet and using it remotely. Keep in mind that Ubuntu Core is aimed at production deployments. We recommend you use Ubuntu Core…

Thanks for bringing this up. I think we should have done a better job making this clearer. I’ll update the docs to make it more explicit.

degville · 2022-06-22T15:43:44.994Z

We’ve now created a how-to on using SSH keys to access an Ubuntu Core device: Connect to Ubuntu Core with SSH

sergiusens · 2023-03-26T19:06:58.642Z

degville:

Ubuntu Core 22 (UC22)
Ubuntu Core 22 (stable) Daily Build

Is there a reason this doesn’t this point to Ubuntu Core 22 (stable) Daily Build ? FWIW, neither of these UC22 install targets (ubuntu-core-22-amd64.img.xz) works for me if I target a laptop (UC20 seems to at least boot)

rpjday1 · 2023-03-27T09:23:40.458Z

I was just about to leave the same comment – why UC22 links to “pending” directory.

degville · 2023-03-27T09:43:40.976Z

(and @sergiusens) Thanks for flagging this. There’s no current reason why this was pending. It was copied from Support platforms which also had the same link, and I think at one time only Pending images were working. I’ve updated both now. I’ll also test the new images - although I did test x86_64 UC22 images with KVM last week.

Edit: Also edited to be HTTPS.

rpjday1 · 2023-08-01T14:32:25.904Z

UC18 is already technically EOL.

rpjday1 · 2023-09-22T07:47:00.605Z

Again, references to “Intel NUC” should be updated. And do we even want to keep documenting anything related to UC18 at this point?

degville · 2023-09-22T08:06:45.110Z

You’re right. I’ve cut the reference to 18 and removed the Intel from NUC.

thp · 2024-01-03T12:46:13.944Z

This page mentions that one has to decompress the downloaded images with “xz”. While this is true for the dd case (or just pipe xzcat’s output into dd), for the Raspberry Pi Imager case, this is unnecessary, as the tool handles decompression automatically (and it’s faster and causes less SSD wear on your machine if one can just decompress on the fly during flashing).

This is also mentioned on the “Raspberry Pi” subpage:

The xz file can be selected without being decompressed first.

(Oh, and Installing Ubuntu Core on a NUC | Ubuntu already shows the xzcat use case, so definitely the documentation has all the parts in there, just on this page, it’s mentioning a different method.)

farshidtz · 2024-03-14T19:19:31.958Z

On the published version here, the hyperlink for “Install on a Raspberry Pi” is https://ubuntu.com/core/docs/install which is the URL of the same page. It should be https://ubuntu.com/core/docs/install-on-a-raspberry-pi.

degville · 2024-03-15T07:57:42.885Z

Thanks for letting us know. I think that problem as actually a broken redirect at the time - we had some issues with these over the last couple of days. But we’re also editing these pages quite significantly ahead of the 24.04 release, which is why they keep changing, although the new structure should be set now.