hyperhive/nix/host-modules/local-defaults.nix
atlas 048bdd29a8 refactor(nix): make all-local a deployment mode, not a default
mara: enableAllLocalDefaults is more of a deployment mode via settings
set, less a default setting.

That reframing is the change. A mode asserts values; an option declares
what it is when nobody asks. Written as default = <flag>, every service
option had to name a switch it has no relationship to, and the answer to
what does all-local turn on was spread across five files.

Two modules now hold the two tiers - local-defaults.nix for the mode and
what it asserts directly, swarm-required-services.nix for the
services-live-here switch and the per-service enables under it. Each
service module keeps its own declaration and loses only the line about
when a deployment wants it.

mkDefault is the right precedence rather than a compromise: it beats an
option default and yields to any explicit definition, so the mode fills
in for an operator who has not spoken and never argues with one who has.
Evaluated config is unchanged in both directions.
2026-08-05 19:41:11 +02:00

58 lines
2.4 KiB
Nix

# The all-local deployment mode.
#
# `enableAllLocalDefaults` is a *mode*, not a default other options read:
# it says "this box is the whole deployment" and then asserts the values
# that follow from that. mara, on the issue: it is "more of a deployment
# mode via settings set, less a default setting".
#
# That distinction is why the derivations live here as `mkDefault` in a
# `config` block rather than as `default =` inside each option. An option
# declares what IT is and what it is when nobody asks; a mode declares
# what a deployment shape implies. Written the other way round, every
# service option had to name a flag it has no relationship to, and the
# answer to "what does all-local turn on?" was spread across five files.
#
# Adding an autoconfigurable thing later means one line here — not a
# `default =` in the new module pointing back at this flag.
{
lib,
config,
...
}:
let
cfg = config.services.hyperhive;
in
{
options.services.hyperhive.enableAllLocalDefaults = lib.mkOption {
type = lib.types.bool;
default = false;
example = true;
description = ''
Run the whole swarm on this host. Turning this on asserts the
swarm-level toggles that an all-on-one-box deployment implies:
the swarm's shared services
(`services.hyperhive.swarm.enableRequiredServices`) and the swarm
CA (`services.hyperhive.swarm.ca.autoConfigure`).
**Off by default, and that is the load-bearing part.** A swarm's
services and its hives can live on different hosts, and a host has
no way to tell which ones it is meant to be so this is an
operator saying "this is that box", never something inferred.
Turn it on for a dev box or a single-hive swarm and get a working
deployment with no further configuration; leave it off and every
swarm-level artifact is operator-provided.
Each toggle it asserts can still be set explicitly, which wins
so "all local except X" needs no new option.
'';
};
# What the mode asserts. `mkDefault` (priority 1000) beats an option's
# own `default` (1500) and loses to any explicit definition, which is
# exactly the precedence a deployment mode wants: it fills in for an
# operator who hasn't spoken, and never argues with one who has.
config.services.hyperhive.swarm = {
enableRequiredServices = lib.mkDefault cfg.enableAllLocalDefaults;
ca.autoConfigure = lib.mkDefault cfg.enableAllLocalDefaults;
};
}