The check that skips copying a base the mesh already holds asked with no Accept header, and a
registry answers a manifest only in a media type the caller named: the same digest answered 200 with
the manifest types and 404 without them. So the builder concluded it held nothing, copied every
vendor base again, and exhausted the public hub's pull limit a second time today.
The test could not have caught it, because the fake registry answered a manifest HEAD regardless of
Accept — more permissive than the thing it stands in for. It is now as strict as a real registry, and
fails without the fix.
One store, and it is the registry the bootstrap already pulls from. An
OCI registry is a content-addressed blob store that also understands
images: PUT a blob and it is retrievable at /v2/<name>/blobs/sha256:… for
ever, by digest. An archive is a content-addressed blob.
A second store beside it was considered and is the right answer for
objects that are mutable, need per-reader access, or are not build output
— somebody's uploads, a backup, a thing with a lifecycle. None of that
describes a digest-pinned archive, and running a second service to hold
one kind of immutable blob is two things to run, two to back up, and two
ways for an artifact to be missing. Overturnable by reading: the manifest
carries a URL and a digest, and neither says what served it.
`build <repository>` clones, reads module.json, builds what it declares,
publishes, and records the manifest with the commit it came from. It is a
command rather than something the control plane does on its own, because
building runs things on a machine and what the control plane may send a
machine is bounded by the declaration language. This is the shape the
builder module takes when it is given work over the broker.
Proven end to end on a real repository and a real registry: a shell
module with a package, a user and a dotfile archive built, published,
fetched back at the digest it declared, rebuilt to the same digest, and
its manifest accepted by the host's own parser — including `user` and
`archive`, which did not exist this morning.
A tag is never accepted as a pin, and a blob already stored is not sent
again — it is named by its content, so re-uploading asks the registry to
store what it already has under the name it already has.
jschoubben