The bundle recipe: the one that both builds and packs. An archive packs a
directory as it stands, so shipping compiled output meant compiling somewhere
first — which meant a Dockerfile repeating the same incantation in every module.
Two base arguments with no defaults, a working directory chosen so the SDK
resolves upward, the compiler invoked by absolute path because the usual symlink
is resolved away when the base image is assembled, a second stage, an environment
variable naming the entrypoints. Most of the catalogue is unconverted and that is
why; two conversions done in one session were each wrong twice with a working
example open in the next window.
A bundle says a language and a list of entrypoints. The mesh knows what the
language implies. Anything a module could override there it would be writing a
Dockerfile to override, so a toolchain is deliberately not configurable.
Declared rather than inferred, both of them: guessing the language from which
files are present makes a build depend on a directory listing, and guessing the
entrypoints makes it change meaning when somebody adds a helper.
A toolchain the mesh does not hold is refused before anything is compiled, naming
what to build first — the same treatment a missing base already gets, because it
is the same question and somebody can answer it. A language the mesh does not
build is refused saying what would have worked, since the author is usually one
word away.
The list of languages is closed and adding to it is a decision. Every language is
another implementation of the contracts every module shares, and those change
rarely and cascade when they do (ADR 0039) — a mesh whose SDKs disagree about the
envelope fails by ignoring messages rather than by failing to compile.
Claude-Session: https://claude.ai/code/session_01D6qtiYU3P9jk3pnAXyAFyx
A module usually runs software somebody else built: a database module
ships configuration and a provisioner and does not build a database. It
could name the upstream reference directly, and then every machine needs
a route to a public registry and the reference is a tag somebody else can
move — which is what pinning exists to prevent.
So an artifact may be `upstream`: pulled by the reference the module
names, pushed into the mesh's own registry, and pinned by the digest that
registry assigns. This is what the bootstrap already does by hand; it is
now something a module can say.
Refused: an upstream reference with no tag or digest, because what gets
mirrored would be whatever `latest` means today and a module pinned to
that is not pinned. And the rule that a build reads only its own
repository does not apply to it — applying it anyway refused every
reference with a registry host in it, which the test caught.
Written by trying to write a real postgres module and finding it could
not be said. It can now: two directories, two containers pinned by
digest, a superuser password sealed to the machine, and the grants
manifest — six resources from one assignment, all accepted by the host's
own parser.
That exercise also found my manifest wrong rather than the host: a
container declared `restart-on`, which is a service field, and the host
refused it by name. It is right to. A container whose own definition
changes is recreated, and a file it mounts is read by the process inside,
which is that image's business.
document
The manifest in a repository names artifacts; the manifest the mesh holds
names digests. Keeping them the same file would mean a repository
carrying a digest — wrong the moment anybody edits anything, and pinning
a value nobody could have checked.
So a resource says `"artifact": "server"`, and resolving a build rewrites
it to the image reference or the archive's source and digest, removing
the build-time word entirely. The host has never heard of an artifact and
its strict decoder would refuse one, at the worst moment.
A module that builds nothing is ordinary and needs no build section —
most of what a person installs is configuration, and a field that exists
to be left blank is a field nobody fills in correctly.
Refusals worth having:
- an artifact declared and not produced blames THE BUILD, not the
resource. Both are failures and the remedies are in different places;
telling somebody to fix the wrong one costs an afternoon. Found by
injection: the first version's message could not be told apart from
the resource-level one, so the check was not actually tested.
- a build reads its own repository and nothing else. An input path
leaving it makes what gets built depend on whatever happens to be on
the machine building it.
- two artifacts with one name, because a resource naming it could mean
either.
jschoubben