minimal installer: support cloud-init

[wmertens]

Fixes #39076

Things done

• Tested using sandboxing (nix.useSandbox on NixOS, or option build-use-sandbox in nix.conf on non-NixOS)
• Built on platform(s)
  • NixOS
  • macOS
  • other Linux distributions
• Tested via one or more NixOS test(s) if existing and applicable for the change (look inside nixos/tests)
• Tested compilation of all pkgs that depend on this change using nix-shell -p nox --run "nox-review wip"
• Tested execution of all binary files (usually in ./result/bin/)
• Fits CONTRIBUTING.md.

---

[Mic92]

This adds python + libraries to the iso. How much does this increase the image size?

[wmertens]

Python 2.7 is already in the minimal image, so I'm hoping not much. I hope I can find out via ofBorg :)

[wmertens]

ouch, running nix-shell -p cloud-init on the minimal ISO turns into a 60MB download and 500MB unpacked :-/

Not sure if that is the best way to test though.

[Mic92]

We have modules/virtualisation/nova-config.nix do we offer a cloud image somewhere?

[wmertens]

Another approach would be to have a minimal script like the one @copumpkin wrote for AWS. Parse at least the ssh stuff and expect a nix expression for the rest. User data is free-form…

[wmertens]

@GrahamcOfBorg build nixos.iso_minimal.x86_64-linux

[GrahamcOfBorg]

No attempt on x86_64-linux (full log)

The following builds were skipped because they don't evaluate on x86_64-linux: nixos.iso_minimal.x86_64-linux

Partial log (click to expand)

Cannot nix-instantiate `nixos.iso_minimal.x86_64-linux' because:
error: attribute 'nixos' in selection path 'nixos.iso_minimal.x86_64-linux' not found

[GrahamcOfBorg]

No attempt on aarch64-linux (full log)

The following builds were skipped because they don't evaluate on aarch64-linux: nixos.iso_minimal.x86_64-linux

Partial log (click to expand)

Cannot nix-instantiate `nixos.iso_minimal.x86_64-linux' because:
�[31;1merror:�[0m attribute 'nixos' in selection path 'nixos.iso_minimal.x86_64-linux' not found

[wmertens]

@GrahamcOfBorg build iso_minimal.x86_64-linux

[GrahamcOfBorg]

No attempt on x86_64-linux (full log)

The following builds were skipped because they don't evaluate on x86_64-linux: iso_minimal.x86_64-linux

Partial log (click to expand)

Cannot nix-instantiate `iso_minimal.x86_64-linux' because:
error: attribute 'iso_minimal' in selection path 'iso_minimal.x86_64-linux' not found

[GrahamcOfBorg]

No attempt on aarch64-linux (full log)

The following builds were skipped because they don't evaluate on aarch64-linux: iso_minimal.x86_64-linux

Partial log (click to expand)

Cannot nix-instantiate `iso_minimal.x86_64-linux' because:
�[31;1merror:�[0m attribute 'iso_minimal' in selection path 'iso_minimal.x86_64-linux' not found

[dezgeg]

Doesn't cloud-init block bootup until it manages to reach the metadata server? I can't recall exactly where I encountered that but IIRC it does.

[wmertens]

Hmm that would make sense. In that case rolling our own would definitely be the best option.

…

On Wed, Apr 18, 2018, 2:26 AM Tuomas Tynkkynen, ***@***.***> wrote: Doesn't cloud-init block bootup until it manages to reach the metadata server? I can't recall exactly where I encountered that but IIRC it does. — You are receiving this because you authored the thread. Reply to this email directly, view it on GitHub <#39088 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/AADWlvDs8o1fn8NLslX5EfqTyMh_1U1Iks5tpogzgaJpZM4TZEmQ> .

[wmertens]

I'm closing this, I'll continue the conversation in #39076 to come up with something better suited to NixOS.