`swarm-bao-matrix-token` reads `secret/swarm/matrix/registration-token`
and is refused with `Code: 403 — permission denied`, measured on this
host at 16:17:49Z after a successful cert login.
path.rs makes every swarm path `swarm/<kind>/<name>/…` where Kind is a
closed set of four: agents, hives, services, controller. `matrix` sits
where a kind belongs, so policy.rs's read document — which emits exactly
`swarm/agents/*` and `swarm/hives/<hive>/*` — cannot cover it. The
module's own doc predicted this: "a misspelled kind is a 403 at provision
time rather than anything a compiler sees".
Moves the token to `swarm/hives/<hive>/matrix/registration-token`, built
through principal_prefix(Kind::Hive, …) like its per-hive sibling
queue::agent_client_path. The policy is untouched: render already grants
that prefix. mara chose this over widening the namespace.
The nix reader interpolates hyperhiveCfg.hiveName, with the no-fallback
reasoning glue-bao-tls.nix already gives at its own use of it.
path.rs's MOUNT doc justified itself by citing the old literal, which
this commit deletes; rewritten to cite the nix reader instead.
Scope: this makes the read reachable, not the value present. Nothing
writes that path yet, and a 403 says nothing about presence — the two
are separate findings and only the first is fixed here. No migration:
nothing ever wrote the old path and no read ever succeeded.
Gate: cargo fmt 0, cargo test -p swarm-secret-client 0 — 32 passed
against a 29-passed baseline with the change stashed, so the three new
tests are accounted for rather than assumed.
Refs #4308
The crate had a single path convention and it was per-agent:
`swarm/agents/<agent>/matrix/<account>`. The secrets still to move into the
store do not fit it — one belongs to a hive, one to a swarm service, one to
the controller itself — so each would have picked its own shape, and each
would have been a separate grant to get wrong.
mara ruled the scheme on the epic: `swarm/<kind>/<name>/<secret>`, over
`agents`, `hives`, `services` and `controller`. This lands it.
`Kind` is an enum rather than free strings for one reason: the store's grant
is written in nix and cannot be reached from Rust, so a misspelled kind is a
403 at provision time and not a compile error. `Kind::ALL` lets a test
enumerate the set instead of restating it, which is what makes adding a kind
a deliberate edit rather than an accidental grant.
Note `Kind` sits beside `checked_segment`'s existing `kind` argument, which
means something else entirely — the label of the name being validated. They
are not the same concept and should not be merged.
Nothing about the rendered policy changes. `policy::render` still grants read
on the agent kind alone; the other kinds are absent on purpose, because what a
hive may read of its own kind is a boundary question and not a consequence of
the namespace growing. The controller's write grant likewise stays scoped to
`agents/` — it widens when a path outside it gains a writer, not when the
kinds are declared.
Verified: `cargo test -p swarm-secret-client` 23 passed, 0 failed. The two
tests pinning the rendered strings (`the_document_grants_read_over_the_whole_agent_prefix`
and matrix's path assertion) still assert the same literals they did before,
which is what shows this is a faithful port rather than a reshape. `nix fmt`
710 emitted, 10 formatted, 0 changed; the three scripts/check-*.sh lints pass
with the change staged. No reference to the removed `path::AGENT_PREFIX`
survives in the crate or in nix — checked with a scoped pattern, because the
unqualified name also belongs to hive-host-sock's container prefix and greps
for it are answering a different question.
mara, reviewing the previous commit: "the field is specific to matrix, why
add it to the general struct". She is right, and the answer is that there was
no general struct — `Credential` had one consumer, the crate's only path
builder was `matrix_account`, and `value` is pinned by
`glue-matrix-bao-token.nix`, a matrix unit. It was matrix's throughout,
wearing a general name; adding `homeserver` is what made that visible.
`client` now moves whatever type a caller names and decodes nothing itself.
That is forwarding rather than machinery: `vaultrs::kv2::read`/`set` are
already generic over the payload.
The matrix agreement moves to its own module holding both halves — where a
credential lives (`account_path`, was `path::matrix_account`) and what the
object at that path holds. `path` keeps only what every path obeys, so a
second kind of swarm secret becomes a module beside `matrix` rather than
another optional field on a struct it shares. argus raised the same collision
from the other direction on #4092: two mutually-exclusive `Option`s modelling
one concept is the failure mode this forecloses.
`checked_segment` stays public in `path`: hive-priv builds an on-disk path
from the same names and must accept the same charset.
Behaviour is unchanged. The compatibility properties move with the struct —
`Option` is what lets a pre-`homeserver` stored object decode, and
`skip_serializing_if` is what keeps a token-only object free of
`"homeserver":null` for that nix reader.
Refs #3726
