[SOLVED] understanding cloud-init provisioning

[lethargos]

I've been reading various resources on the internet related to cloud-init, including the proxmox documentation on this, but I'm still finding it difficult to understand exactly how it works and how you're supposed to provision it.

Basically, I would like to understand the relationship between the cloud-init configuration as a snippet (yaml) and the cloud-init drive that is supposed to mount some kind of iso.

If, for example, I install Ubuntu 20.04, then add the cloud-init drive and edit the configuration (network, user, ssh, whatever) in the GUI as is, it is simply ignored.
I was able to make it work with Debian 10, after manually installing cloud-init, so I'm not sure where the difference lies.

I'm looking forward to advice on how to provision Ubuntu 20.04 initiall only using the cloud-init drive and then integrating the snippet somehow and the difference between the two.

Thanks.

 

[mira]

The `snippet` is just an alternative way to specify a config which is more flexible than setting the options via the GUI/API, but at the cost of no GUI support. It also supports anything cloud-init itself supports, as it is passed through 1:1. The GUI/API is limited to a small subset of useful options.

If you don't use a cloudimg, you have to manually install the cloud-init package. It is advised to configure it the way you want inside the guest (/etc/cloud/cloud.cfg), and then run `cloud-init clean` before shutting it down for creating the template.
This will make sure that on the next boot, when you have a cloud-init drive attached, it will actually read it and configure the guest accordingly.

 

[lethargos]

Thanks for the reply. I don't think cloud-init clean is enough actually to reset cloud-init. It didn't work for me, at least. You also need to remove /etc/cloud/cloud.cfg.d/subiquity-disable-cloudinit-networking.cfg and add under /etc/cloud/cloud.cfg.d a file called for example 99-pve with the following content:

datasource_list: [ NoCloud ]

This is how it it eventually worked in my case.

(You can use "ICODE" between square brackets in order to do inline code highlighting )

 

[lethargos]

Hello,

Another question related to this topic: can the cloud-init configuration in the snippet be loaded independently of the cloud-init drive?
I was reading the documentation for the proxmox provider of terraform (https://registry.terraform.io/providers/Telmate/proxmox/latest/docs/guides/cloud_init) and there it says:

Now, there is one other way to get the configuration data into the guest without using this magical CloudInit CD-ROM and that's by using cicustom.

Is this accurate? I can just set cicustom and disable the cloud-init drive?

 

[mira]

No, it just takes the config from the snippets instead of generating it based on the VM Config.
The config is then still put in an ISO and attached as CD-ROM.