Can you describe steps how to test the backend?

I'll try to add documentation and tests this weekend. So far it's working great! Nixops is so much better than ansible/terraform for this use case.

documentation and trivial example added. Still needs tests.

So glad to see this getting some attention! Yay!

Hi, I pulled these 2 commits into my local tree, which is caught up with master. Installation works fine, but as soon as I reboot the instance, it fails to mount the root filesystem.

...
running udev...
starting device mapper and LVM...
Scanning for Btrfs filesystems
mounting /dev/vda1 on /...
mount: mounting /dev/vda1 on /mnt-root/ failed: Invalid argument

An error occurred in stage 1 of the boot process, which must mount the
root filesystem on `/mnt-root` and then start stage 2.  Press one
of the following keys:

   r) to reboot immediately
   *) to ignore the error and continue

Are you seeing this at all? I followed the steps outlined in https://www.vultr.com/docs/install-nixos-on-vultr, the only difference being that I used ext4 rather than btrfs on the root filesystem.

Yeah, btrfs is currently hard-coded in the backend python file (similar to ext4 being hard-coded in the digital ocean one). I need to mess around with it and see what would need done to move that into the config object instead. I'm looking at the libvirtd implementation of nixops to see how I could do that, but not making much progress.

Ahh, ok. Thanks for the clarification, I’ll try to work around this.

Instead of the custom snapshot, wouldn't it be easier to use the smallest image they have and run https://github.com/jeaye/nixos-in-place on it? That would make using Vultr as simple as providing your credentials…

I agree that the best UX would be to only provide the credentials and let nixops worry about the rest. I wonder how hard it would be for nixops to create a snapshot on its own. But I would be more than happy to have a first version of vultr support in nixops, even if it would still require the manual steps.

@pierrebeaucamp you're right, it shouldn't block inclusion. Once you have a snapshot you can basically use it forever.

I would like to see https://www.vultr.com/api/ mentioned on where to get the dcid and vpsplanid values. (funny, I just noticed you can't get the $2.5 sandbox plan via the API). Since you can only really get those values via the API, perhaps there could be a command to retrieve those values? I don't know if nixops allows custom commands like that… Perhaps get those values if they are missing from the description?

Please do this in a plugin.