ADR 0156: an artifact is what a build produces, and the store's seat is named for its scope (group 4, step 3) #233

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jschoubben merged 1 commits from feat/the-artifact-store-seat-is-named-for-its-scope into main 2026-09-30 19:17:28 +00:00
6 changed files with 108 additions and 7 deletions
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@@ -52,8 +52,11 @@ another — and a mesh you cannot name precisely is a mesh two people describe d
- **package** — what code resolves when it is **compiled**: an npm/cargo/pypi dependency, by
**version**. Served by the **package-registry** (gitea). Only a builder talks to it.
- **artifact** — what the mesh delivers to a machine to **install and run**: an OCI image, by
**digest**. Served by the **artifact-store** (distribution). Every node pulls from it.
- **artifact** — anything a build produces and the mesh delivers to a machine by **digest**: an
`image`, a mirrored `upstream` image, a `bundle` of the module's own code, an `archive`. Served by
the **artifact-store**, an OCI registry that holds every kind as content-addressed blobs
([ADR 0156](../02-DECISIONS/0156-an-artifact-is-what-a-build-produces-and-the-store-is-named-for-its-scope.md)).
Every node pulls from it. An image is one kind of artifact, and a module is not an image.
- These are two protocols, not one store being weak — see [ADR 0075](../02-DECISIONS/0075-two-stores-and-which-provides-what.md).
## How modules relate to the mesh
@@ -81,7 +81,9 @@ closed set stays what its name says it is: the *system's* roles, not everyone's.
- **`the-uplink` → `node-uplink`** ([ADR 0125](0117-a-machines-uplink-is-a-seat.md)). Unheld, so it
renames with no migration.
- **The registry seats — `the-artifact-store`, `npm-package-registry` (→ `mesh-artifact-store`,
`mesh-npm-package-registry`) — and `git` (→ `mesh-git`) — are decided but deferred.** They each
`mesh-npm-package-registry`) — and `git` (→ `mesh-git`) — are decided but deferred.** *(The
mechanism changed — 2026-09-30, by ADR 0156: `the-artifact-store` is renamed, one update and one
alias under ADR 0122; the other two stay deferred.)* They each
*deliver* a provision, so renaming them is a delivering-seat migration: a holder that stops
resolving mid-flight takes a provision away from every consumer. That risk is not worth carrying in
the same pass as the node-* renames, so they keep their names until done deliberately.
@@ -0,0 +1,83 @@
---
topic: the mesh
status: accepted
date: 2026-09-30
deciders: jochen
reconstructed: false
extends: 02-DECISIONS/0075-two-stores-and-which-provides-what.md
---
# 156. An artifact is what a build produces, the artifact store serves every kind, and its seat is named for its scope
## Context
[Issue 123](../04-ISSUES/123-the-image-registry-is-named-after-a-role/00-report.md) found three
wordings disagreeing about the mesh's registry. The glossary defined *artifact* as "an OCI image, by
digest"; the manifest's build vocabulary names four kinds — `image`, `upstream`, `bundle`, `archive` —
and the catalogue builds all four; the seat was `the-artifact-store`, the last of the mesh's own seats
named after the job it does rather than for the mesh
([ADR 0121](0121-a-system-seat-is-named-for-its-scope-and-modules-define-their-own.md) decided the
rename and deferred it). The issue asked whether the seat and provision should be renamed after
images, and whether the mesh needs two registry implementations at all.
Reading what the store actually serves settles the first question the other way. A kept reference
has two shapes — `artifact-store://<module>/<artifact>@sha256:…` for an image and
`artifact-store://<module>/<artifact>/blobs/sha256:…` for an archive — and both are served by the
same OCI registry, by digest. [ADR 0075](0075-two-stores-and-which-provides-what.md) already
defined the provision that way: *content-addressed blobs, pinned by digest, no versions, no ranges;
what the mesh delivers to machines*. The provision was never an image registry. Only the glossary said
so, and only the seat's name was odd.
## Considered Options
**1. Rename the seat and the provision after images.** Rejected. The store serves archives too, by the
same protocol; naming it for one kind would be the glossary's mistake made permanent, in the name
every manifest uses.
**2. Fix the word, rename the seat for its scope, keep the provision.** Chosen. The rename ADR 0121
deferred as a delivering-seat migration is, since [ADR 0122](0122-a-seat-is-data-a-rename-is-a-database-update.md),
one update and one alias: the former name resolves forever, a held record follows by cascade, a claim
written with the old name still holds.
**On two implementations:** left as 0075 decided. Two provisions because two protocols; the OCI
registry the genesis installs because something must serve images before the mesh can build; the
forge may provide `artifact-store` too and a mesh may choose it. The bootstrap argument is weaker than
it reads, as 123 says, and the day the forge is raised at genesis and adopted in place is the day to
retire the second server — a migration a mesh performs, not a decision to take here.
## Decision
- **An artifact is anything a build produces** — an image, a mirrored upstream image, a bundle, an
archive — and the glossary says so. *Image* is one kind. A module is not an image; a module may
build several artifacts and install none.
- **The artifact store serves artifacts of every kind a machine fetches**, images and archives, by
digest, over the OCI registry protocol. The provision keeps its name.
- **The seat is `mesh-artifact-store`.** `the-artifact-store` is its alias. The catalogue's registry
module claims the new name; a definition elsewhere claiming the old one still holds.
- The two other deferred renames — `npm-package-registry` and `git` — stay deferred, and for the
same reason no longer. They are one migration each when wanted; nothing here needs them.
## Consequences
- The glossary stops contradicting the manifest vocabulary, and a reader of `artifact-store` reads
it as what it is: where the mesh's built things are kept.
- One migration on the seat table; no manifest but the registry's changes; no consumer of the
provision changes, because the provision did not.
- **What got harder:** nothing measurable. A record that says `the-artifact-store` is read through the
alias; design 26's table already carried the new name as intent.
## How this is checked
| Rule | Checked by |
|---|---|
| The former name resolves to the seat once the store's aliases are loaded | a catalogue test |
| The seat is in the compiled set under its new name, delivering `artifact-store` | the seat tests, updated |
| The registry module holds the seat under the new name on the live mesh | `seats` after the rollout |
| The glossary's *artifact* matches the build kinds a manifest may declare | design 18's table and the showcase module list the kinds; the glossary names the same four |
## References
- [issue 123](../04-ISSUES/123-the-image-registry-is-named-after-a-role/00-report.md)
- [ADR 0075](0075-two-stores-and-which-provides-what.md) — extended: the provision as defined stands, the word is corrected
- [ADR 0121](0121-a-system-seat-is-named-for-its-scope-and-modules-define-their-own.md), [ADR 0122](0122-a-seat-is-data-a-rename-is-a-database-update.md) — the rename, decided and made cheap
- mesh-controller migration 0048; mesh-catalog `modules/distribution`
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@@ -169,6 +169,7 @@ python3 00-META/checks/index.py fail if stale
- **0134** — [The mesh says what it applied](0134-the-mesh-says-what-it-applied.md)
- **0142** — [The mesh delivers its own components as binaries, not as container images](0142-the-mesh-delivers-its-own-components-as-binaries.md)
- **0154** — [The mesh's own verbs are the mesh-controller seat's tools, and which verbs those are](0154-the-meshs-own-verbs-are-the-controller-seats-tools.md)
- **0156** — [An artifact is what a build produces, the artifact store serves every kind, and its seat is named for its scope](0156-an-artifact-is-what-a-build-produces-and-the-store-is-named-for-its-scope.md)
### Its tiers, from the bottom up
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@@ -109,7 +109,7 @@ convention, which later seats departed from.
| `mesh-store` | — | mesh | — | the store the mesh's own records live in |
| `mesh-broker` | — | mesh | `mesh-bus` | the broker carrying the mesh's own bus |
| `mesh-vault` | — | mesh | `secret`, reserved | the vault |
| `mesh-artifact-store` | `the-artifact-store` | mesh | `artifact-store` | the artifact registry |
| `mesh-artifact-store` | `the-artifact-store` (renamed 2026-09-30, [ADR 0156](../../02-DECISIONS/0156-an-artifact-is-what-a-build-produces-and-the-store-is-named-for-its-scope.md)) | mesh | `artifact-store` | the artifact registry |
| `mesh-catalog` | `the-catalogue` | mesh | — | the catalogue |
| `mesh-npm-package-registry` | `npm-package-registry` | mesh | `npm-package-registry` | the forge |
| `mesh-git` | `git` | mesh | `git` | the forge |
@@ -1,9 +1,9 @@
---
status: located
status: resolved
opened: 2026-09-26
located-in: [hq 00-META/glossary.md, hq 02-DECISIONS/0075-two-stores-and-which-provides-what.md, mesh-controller internal/catalogue/seats.go, mesh-catalog modules/distribution]
fixed-by:
amended-design:
fixed-by: ADR 0156; mesh-controller migration 0048 (feat/the-artifact-store-seat-is-named-for-its-scope); mesh-catalog modules/distribution
amended-design: 03-DESIGN/01-to-be/26-the-seats.md
---
# 123 — The image registry is named after a role, and *artifact* is defined as one format
@@ -72,3 +72,15 @@ adopted, rather than on protocols.
exercise that leaves the code disagreeing?
- What check would keep the glossary honest — a definition tested against the kinds a definition may
actually declare, rather than restated by hand?
## Resolved, 2026-09-30
Read from what the store serves rather than from what it was called: both shapes of a kept reference
— an image and an archive's blob — go to the same registry by digest, which is exactly the provision
ADR 0075 defined. So the word was wrong and the seat's name was odd, and the provision was right.
[ADR 0156](../../02-DECISIONS/0156-an-artifact-is-what-a-build-produces-and-the-store-is-named-for-its-scope.md):
*artifact* means what a build produces, of any of the four kinds; the seat is `mesh-artifact-store`
with the old name as its alias (one migration, ADR 0122's mechanism); the provision keeps its name.
The two-implementations question stays as 0075 answered it, with the day to retire the second server
named. The mechanical check the report asked for is the alias test and the glossary naming the same
four kinds as design 18's table.