[Nix-dev] Proposal: Standard installation procedure

[Mathijs Kwik]

Have a look at
https://github.com/bluescreen303/bluenix/blob/master/jobs.nix
It's overly complicated and I'm gonna simplify it, but it does build
multiple systems.



Ertugrul Söylemez <ertesx at gmx.de> writes:

> On Mon, 20 Oct 2014 09:50:15 +0200
> Eelco Dolstra <eelco.dolstra at logicblox.com> wrote:
>
>> > The basic idea is this:  To build a system, you use a standard
>> > function from Nixpkgs and pass it a configuration module.  The
>> > result is a derivation that represents a complete self-contained
>> > system.
>>
>> How does that differ from how NixOS is currently implemented? You can
>> do:
>>
>>   $ nix-build '<nixpkgs/nixos>' -A system
>>
>> which gives you a complete system in ./result, where
>> e.g. ./result/init is the stage 2 init script that runs the activation
>> script and invokes systemd.
>
> How would I refer to multiple systems with different configurations from
> within a Nix expression?  The change would allow this:
>
>     { system1 = import <nixos/build-system.nix> module1;
>       system2 = import <nixos/build-system.nix> module2;
>       system3 = import <nixos/build-system.nix> module3; }
>
>
>> Programs like nixos-rebuild, nixos-install, nixos-container and even
>> NixOps are really just wrappers around this (except that they add
>> various levels of provisioning).
>
> They all make the assumption that there is exactly one current system
> configuration.
>
>
>> > In other words a container-based NixOS system is really just a Nix
>> > store, nothing more.  It doesn't need to contain any additional
>> > files or directories and building it does not require us to
>> > understand the complexity of nixos-install, because it will all be
>> > moved to the system initialisation phase.
>>
>> I don't think nixos-install is that complex. Almost all of the
>> initialisation it does in the target file system is to make nix-build
>> work in the chroot. The NixOS initialisation is done by the activation
>> script.
>>
>> Check out "nixos-container create" - it does almost no initialisation
>> of the container file system, since everything is done by the
>> activation script during the first boot of the container.
>
> That's already most of what I need.  What remains is a way to build
> multiple configurations and deploy them to different systems in a
> functional way, in particular without environment variables.
>
>
> Greets,
> Ertugrul