Appliance Creation based on Ubuntu 22.04 distro

Development one-apps
1

Hello OpenNebula Team!

I want to create an appliance based on the Ubuntu 22.04 distro in order to upload it to a common OpenNebula marketplace with the other partners of the project. This appliance will include a service installed via a process of six commands. I have watched the OpenNebula webinar: “Introducing one-apps project, an OpenNebula appliance building tool,” and I have some questions.

To create this appliance, should I follow the approach demonstrated with the MariaDB service, or is there a different approach I should take? Specifically, I am aiming to create an Ubuntu Image appliance with a service installed, rather than a service appliance.

If I modify one-apps/packer/ubuntu.10-upgrade-distro.sh to include the commands needed to install my service, will that work? Should I follow the same approach shown in the webinar?

Thank you for your time!

2

In general, the approach followed on the webinar is the “ideal” scenario for a bash based approach. What you could really change is using the ruby framework (more modern one, there is a note about that in the webinar) instead of the bash one.

I am aiming to create an Ubuntu Image appliance with a service installed, rather than a service appliance.

Would you mind explaining this ?

If I modify one-apps/packer/ubuntu.10-upgrade-distro.sh to include the commands needed to install my service, will that work? Should I follow the same approach shown in the webinar?

You can place your logic wherever you want, but if the intention is to create a custom appliance, it would be ideal to have a dedicated script for it and referencing it within the packer code. That script is used in the base ubuntu distro building.

3

Hello Daniel, thanks for the response!

Yes, actually my intention is to create a custom appliance based on the Ubuntu distro.

So,

  1. If I clone the one-apps repo and create a new script in the one-apps/packer/ubuntu directory with the logic of the appliance that I want to have

  2. Then execute this script through the one-apps/packer/ubuntu/80-install-content.sh script

  3. And finally execute make ubuntu (in order to build it)

Is this approach going to work?

4

Yes it will work, however

  • ubuntu is not a good name for a custom app, it could be confusing as there is already ubuntu flavours. But is not a big deal as long as users are aware.
  • you want to execute the script through another script. This means you’d need to modify said script which is stock OpenNebula script.
    • If for some reason we change that context install script, then you’ll need to maintain the change sync.
    • Why not simply add another script with a numbered order ? Packer will call it sequentially.
5

So, if I create a script in one-apps/packer/ubuntu/99-add-logic.sh with the logic of the appliance that I want to create, will it be called automatically?

Yes, I agree that the name “ubuntu” is not a good name for a custom appliance. If I change the variable appliance.name in one-apps/packer/ubuntu/variables.pkr.hcl, will it work?

6

Please check this PR for the code example showcased in the webinar. The script will be called due to how packer references them.