den.base is now den.schema to better reflect its intention.

[vic]

I will start using announcements for this kind of things: heads-up for changes that people might be aware of when using Den's main branch.

PR: #234.

After releasing v0.11.0 some people reached me with questions about den.base.* modules. Mainly because that is the way I recommended people to enable home-manager in the release notes.

Looks like den.base name was not a very good name when it got introduced a while ago. Because the base name is very generic and some people were thinking those den.base.host were aspects themselves. They are not, they are just nix modules that get included as the base for each entity.

For example when you define

den.hosts.x86_64-linux.igloo = {
  is-secure = true; # is-secure is a freeform attribute here.
};

The igloo host submodule automatically imports den.base.host (now den.schema.host).

The intention of den.schema.host is to provide default values/options for all hosts.

The module has _module.args.host = config so it is a fixed-point to access the host itself:

# not an aspect, but meta configuration.
# All hosts include this module, `host` module argument is just `_module.args.host = config`. 
den.schema.host = { host, config, lib, ... }: {
  options.needs-firewall = lib.mkEnableOption "Host ${host.name} should enable firewall";
}

Aspects can access these host.is-secure (freeform attr) or host.needs-firewall (option) values:

hardened-host = { host }: lib.optionalAttrs host.needs-firewall {
  nixos = ...;
  darwin = ...;
};

den.aspects.igloo.includes = [ hardened-host ];

[musjj]

I like this change because now I can use the term base in my own namespaces without feeling conflicted about overloading an existing vocabulary 😄