Designed with no reference to what came before, which was asked for. The
system this replaces has features — several deployable units inside one
module — and they are deliberately absent.
That closes something ADR 0001 has been carrying as an open prerequisite.
It lists "named features with per-node opt-in" as required, or "every
independently deployable unit becomes a module again and the count
returns". The premise was right and the remedy already exists in another
form: several modules, assignment per node, and a module with
requirements and no files of its own. `networking` is exactly that. The
count does not return because what made it return — a module is
expensive, so put several things in one — is gone. A module here is a
manifest and usually nothing else.
The manifest in a repository names artifacts; the manifest the mesh holds
names digests. Two documents, because a digest is not knowable until
something is built and a repository carrying one is wrong the moment
anybody edits anything.
The builder runs on a node. Building needs a container runtime and a
working tree, and what the control plane may send a machine is bounded by
the declaration language. A control plane holding a container socket
would be the one component that can do anything anywhere.
And the host's vocabulary grew from six shapes to eight — user and
archive — with the reasoning for each and for the refusals that came with
them. The count is asserted by a test precisely because every addition
widens what a compromised control plane can express.
