Introduction to Denix Hosts

A Denix host is an attribute set returned by the function delib.host, which enables or disables specific configurations depending on the value of the option ${myconfigName}.host. It also passes the input attribute set of the delib.host function to the ${myconfigName}.host.${delib.host :: name} option.

In simple terms, this allows you to separate the NixOS, Home Manager, and custom options configuration into those that apply only to the current host and those that apply to all hosts. For example, the former can be used to enable or disable certain programs, while the latter can be used to add the current host's SSH key to the authorizedKeys of all hosts.

A host can also be compared to a module, because all hosts are imported regardless of which one is active, but the applied configurations depend on the active host.

Options

For hosts to work, the configuration must include the options ${myconfigName}.host and ${myconfigName}.hosts, which you define yourself in one of the modules.

Here is an example of a minimal recommended host configuration:

{delib, ...}:
delib.module {
  name = "hosts";

  options = with delib; let
    host = {
      options = hostSubmoduleOptions;
    };
  in {
    host = hostOption host;
    hosts = hostsOption host;
  };

  home.always = {myconfig, ...}: {
    assertions = delib.hostNamesAssertions myconfig.hosts;
  };
}

More examples can be found in the Examples section.