The design pass. Everything a module needs is a requirement: a name, a contract, and one of four kinds
of provider — a module, the node's host, the mesh, the operator. Installing a module resolves every
requirement or refuses, naming everything missing at once. It retires six mechanisms that grew
separately: provisions through bindings, settings, assigned ports, machine facts, minted secrets and
literals in the definition.
ADR 0113, proposed: a provider makes what it provides, and the mesh carries it back sealed to the
consumer's node. It is the return path ADR 0048 left "to a separate decision", now needed three ways:
data provisions with nothing to answer with, contracts needing a value the controller cannot make, and
a vault that generates nothing. Who a consumer is stays the mesh's (ADR 0049). Genesis is the one
exception. On acceptance it supersedes 0048 and amends 0085.
ADR 0112 is revised from three sources to that single concept.
ADR 0110 is amended for two points raised in review. The vault gets the mesh-vault seat (issue 106).
A seat's holder outranks co-location for a provision it delivers. Writing that down exposed an
inconsistency: mesh-store delivering postgres-database would have sent every database consumer to the
control-node, against to-be 23's node-local stores. So a seat delivers a provision only where the mesh
has one answer for everyone — artifact store, npm registry, git, vault — and mesh-store and mesh-broker
deliver nothing. 23 and 26 follow.
'Control plane' becomes 'controller' in the records written today.
Seats have been doing two jobs and neither is written down. The mechanism ADR 0009 introduced is
enforced — a second holder is refused — but any well-formed name becomes a seat by being claimed,
and nothing can say which seats a mesh has or who holds them: holdings are assembled while planning
and discarded. The enumeration done while preparing this missed the control plane's own manifest,
because core modules' manifests live in its repository rather than the catalogue.
0110 closes the set. Each seat has a name, a scope, what occupying it delivers, and the record that
made it one; a claim outside the set is refused. A seat is held by a module assignment, and what the
mesh knows about the holder is what it knows about that assignment — nothing is stored beside it. A
seat may deliver a provision, and then its holder answers for it among several providers: pin, then
the holder, then the only provider, then refused. That keeps 0009's "refused, never guessed": the
seat is the choice made once, mesh-wide, instead of a pin per consumer node. The first set is the
eleven seats already claimed plus 0109's npm-package-registry, so nothing in use is refused.
Two concepts — seats for exclusion, a new word for consumable singulars — was rejected: both mean
"this mesh's one X", and the overview a person wants is one list.
0111 gives the mesh a git seat and makes a build source one of two explicit forms: a repository on
the seat's holder, recorded by its path and cloned from wherever the holder runs at build time; or
an external URL, recorded and cloned exactly as given. Recognising self-hosted sources by matching
URLs against the forge's address was rejected — it fails in the one case it exists for, after the
forge moves. Credentials for private repositories are left undecided and said so.
Design: new to-be 26 (the seats); 23 gains the seat step in resolution; 18's source entry names
the two forms; the glossary's seat and provision entries say where they meet. 0109 is carried from
its own branch so every link here resolves.
jochen