Four units read one path each out of the store, and all four logged in
holding `deploy.bao.clientCertFile` — the hive's own leaf. Bao identifies
a principal by the subject of the certificate it presents, so four
readers behind one certificate were ONE principal, and the only grant
expressible was the union of what the four need: read on
`swarm/agents/*`, `swarm/hives/<hive>/*` and `swarm/services/*`. The unit
fetching Grafana's OIDC client secret could fetch every agent credential
in the swarm; the one fetching this hive's matrix token could fetch
Grafana's. Least privilege was not misconfigured here, it was
unrepresentable.
Each now holds a leaf, a cert-auth role and a policy of its own, and each
policy is the single `secret/data/…` path that unit's own script names —
spelled to the leaf, not to a prefix, the way matrix-ctl's already is.
Following the four exemplars in-tree rather than building a mechanism:
`signLeaf` mints the leaves, `swarm-bao.nix` writes the roles from the
bootstrap token, the consumers name their own pair.
Two of the four are written PER HIVE and two are not, which is the shape
of the paths rather than a preference. A matrix appservice token and a
queue credential live under `swarm/hives/<name>/` and every hive runs a
reader for its own, so one role for all of them would have to be granted
`hives/*` — letting one hive read another's, a reach no hive has today.
An OIDC client secret lives under `swarm/services/<client-id>/` and a
swarm registers each exactly once, so one role each is enough. The
per-hive subjects are `<prefix>-<hive>` and swarm.nix reserves every
composed spelling as a hive name, so a hive cannot be named into another
hive's role.
The shared leaf stays: hive-c0re still passes it into its container, the
`bao` CLI wrapper still defaults to it, and the three
`glue-*-bao-identity.nix` files derive the PKI directory from it.
module-eval-bao-grants gains a negative arm per principal — each pins the
three stanzas the hive's leaf carried and the two wildcards a later
widening would reach for, so a policy that grows fails here rather than
in a store. Plus the consuming side: repointing a unit back at the hive's
leaf would evaluate, deploy and log in, and silently restore the union.
A hive that reads a store on another machine now places one leaf per
principal instead of one shared by four. That cost is the point, and
docs/swarm/secrets.md lists the pairs.
Renames `swarm-matrix-minter` and reshapes it around subcommands. Minting
is now `swarm-matrix-ctl mint`.
Running rust inside `containers.hive-matrix` is not free: it needs its own
store identity, its own cert role and its own bind mounts, and every one of
those is per-*container*, not per-task. A second single-purpose crate would
have had to duplicate that plumbing to add one action, so the next thing
that has to run in there should be a verb here rather than a new crate.
The old name guaranteed the opposite.
`main.rs` is clap dispatch; the minting logic moves to `mint.rs` unchanged.
A bare invocation is refused: `mint` writes a credential, so "no verb"
defaulting to it would make a typo in the unit mint rather than fail.
The environment prefix moves with it, `MATRIX_MINTER_*` → `MATRIX_MINT_*`.
Scoped to the verb and not to the binary, because a binary-scoped prefix is
one the next verb has to share or widen, and a widened one never narrows
again. A test asserts every variable carries the verb's prefix.
The principal renames too. The cert role, bao policy, granting unit, leaf
filename and `certAuthCns` entry all have to spell one string the same way,
so leaving them as `swarm-matrix-minter` would have rebuilt the naming
split this branch exists to remove. Renaming the nix options alongside is
free here: every one of them is introduced by this PR and has never been
released, so no operator config names them yet.
`ExecStart` now names the verb, which is a contract between a nix string
and a clap enum that fails at deploy time with no local signal. Both ends
assert it: `mint_is_spelled_the_way_the_unit_invokes_it` in the crate, and
a new module-eval arm reading the rendered `ExecStart`.
docs/getting-started/setup.md drops the sender token from its "live on the
host" list: setup does not touch this credential, so a setup guide has no
reason to name it.
A swarm runs one homeserver and a homeserver has one appservice sender
account, so "mint it once" is a property of the thing being minted
rather than something a lock has to enforce. That is what makes this
account the one to move first: no trigger route, no controller change
and no agent list — a boot-time oneshot beside tuwunel is the whole
mechanism.
`swarm-matrix-minter` runs inside `containers.hive-matrix`, which
already holds the appservice token: the rendered registration is bound
in read-only because that is how tuwunel is handed it. What the
container lacked was an identity of its own, so this adds one — a leaf
from the store's CA with a grant of exactly one path, not the hive's
leaf, which reads every secret in the store.
Both ends of the credential ship here. The minter reads the path it
publishes to before it touches the homeserver, and returning on a
non-empty read IS the "only once"; `hive-c0re`'s `ensure_hive_user`
reads the same path, authenticating with the hive name already in
`HYPERHIVE_HIVE_NAME`. The existing mint-then-`M_USER_IN_USE`-login
ladder stays as the fallback for a store that is empty, unconfigured or
unreachable, which is every swarm deployed before this — so nothing
needs backfilling and nothing breaks if the rest of the sequence never
lands.
The credential is not an admin credential, and is not named like one.
It is the access token of the appservice registration's own
`sender_localpart` — `@hive:<server_name>`, an account the homeserver
creates for itself when it loads the registration. The store path is
`swarm/services/matrix/sender-token`, the host path is
`matrix/access-token`, and the homeserver no longer runs an
`admin_execute` promotion for that account at boot. Everything the hive
provisions with it — the Space, the chat room, their hierarchy and join
rules, the invites — rides on being the creator of those rooms at power
level 100, not on homeserver admin; there is no Synapse admin API here
to need, tuwunel has none.
Two operations do need an admin *sender* and therefore stop working:
`hivectl matrix promote-user` and `hivectl matrix reset-password`, both
`!admin …` messages into `#admins:<server>`, plus the password-reset
recovery path that an agent with a lost password file falls back to.
They are swarm-level operations and are left failing loudly rather than
served by an over-privileged token every other call site would also
carry. The sweep's own admin-rights check and self-repair go with them:
an account that is deliberately not an admin has nothing to check.
`ephemeral = false` stays, and hive root can still read the container's
filesystem. Accepted: what this buys is identity separation — no hive
*process* holds or reads the appservice token — not physical isolation.
Refs #4345
A hive that does not host authelia has no path to its own agent queue
client secret. The mint writes the plaintext to a host directory whose
other reader lives in a different container, so the host that mints is
the only place both trees are addressable — which is where this unit
runs.
Four pieces, in the order they depend on each other: the leaf
(glue-bao-tls.nix signs it, because the thing that owns a private key
owns issuing from it), the module declaring its own cert/key options,
the one-pairing glue file pointing them at that leaf, and the imports.
The unit is gated on holding a client identity, never on
deploy.bao.enable — that option is the co-location assumption itself,
and the publisher is the case that assumption excludes.
The secret is passed to bao as `value=@<path>`, never as an argv
element: bao is an external binary, so an argument is world-readable in
/proc for the life of the call.
Refs #3853
`clientCn` fell back to `cfg.domain` when `hiveName` was unset. That branch
cannot run: `hive-network.nix` asserts `hiveName != null` under
`mkIf services.hyperhive.enable`, and this file's `config` is gated on the same
predicate, so any host that evaluates the conditional has already failed the
assertion.
Worse than dead, it read as a second supported spelling of a hive's identity —
which is what a cert-auth role matches on. It was not even the hive's own
domain: `cfg` here is `services.hyperhive.swarm.bao`, so the fallback resolved
to the store's address, one string shared by every hive in the swarm and the
same CN the server leaf carries.
Reading the option directly matches what other modules needing the name already
do (`hive-c0re/environment.nix`).
glue-bao-tls.nix signs a third leaf. It is minted whether or not a
controller runs here, because the case it serves is the one where it
does not: a controller elsewhere needs a leaf from this CA and cannot
sign one, so issuing it here turns "obtain a certificate out of band"
into "copy this file".
glue-controller-bao-identity.nix holds the pairing and nothing else --
which paths this host's controller reads. Gated on the leaf existing
rather than on deploy.bao.enable, so a controller on the store's host
and one three networks away with an out-of-band leaf get the same
wiring; gating on the store would have made the co-located case the
only supported shape. The directory comes from deploy.bao.clientCertFile
rather than repeating glue-bao-tls.nix's literal, so moving the PKI
moves both.
module-eval gains three cases and two fixtures, because nothing asserted
the PKI script before: an earlier commit added a leaf to that rendered
unit and left the derivation unchanged. The fixture's CN is deliberately
a value no default could supply, so "the role and the leaf both carry
it" says they read one option rather than that both happen to say
swarm-controller.
Gates: 62 module properties hold (59 before, plus these three), on a
derivation hash that actually moved -- this suite is a cache hit when
only fixtures change, so an unchanged hash would have meant the cases
never ran. nix fmt clean, all three scripts/check-*.sh exit 0.
The store declared no journald units and served no metrics: nothing in
`swarm-bao.nix` mentioned either, while every sibling swarm service
declares both.
Metrics get their own loopback listener rather than a flag on the API
one, and that follows from what a scraper can express rather than from
taste: `swarm.otel.scrapeTargets` is `host:port`, plaintext and with no
credential, while the API listener is TLS and demands a client
certificate once a client CA is set. `metrics_only` narrows the new
listener to the metrics path; `prometheus_retention_time` is what serves
the endpoint at all.
Measured against openbao 2.6.2 before writing any of it: the metrics
path answers 200 on such a listener *while the node is sealed and
uninitialised*, 503 on the API listener, and 404 for a non-metrics path
on the metrics listener.
The listener exists only where a collector does — it is unauthenticated
by design for now, and an endpoint with no reader would be exposure
bought for nothing.
The port cannot be the API port + 1: openbao derives every listener's
cluster address as its own port plus one, so that number is already
taken. An assertion says so, since the failure is otherwise a race with
no log line.
Journald units are declared by the module that defines each unit, not
gathered here, matching the option's own rule — a name nothing defines
is silently ignored, so a central list would read as coverage on hives
that have neither glue module.
Refs #3849
`swarm-bao.nix` declared the store's half of the mTLS pair as options —
`serverCertFile`, `serverKeyFile`, `clientCaFile` — and left the reader's
half as a literal inside `glue-bao-tls.nix`, which only runs where
`deploy.bao.enable` is set. A hive that did not host the store therefore
could not read from it and could not be pointed at a certificate even
when one had been placed by hand.
Adds `clientCertFile`, `clientKeyFile` and `serverCaFile` beside their
three server siblings, `mkDefault`ed by the glue to the leaf it already
mints, and moves `glue-matrix-bao-token.nix` onto them. Its gate becomes
"this host holds an identity" rather than "the store is a neighbour",
and the unit ordering that names store-local units is now conditional --
`Requires=` on an absent unit fails the job.
`serverCaFile` is separate from `clientCaFile` on purpose: one is the
store choosing which readers to trust, the other a reader choosing which
store to trust. Self-signing collapses them to one file, which is a
property of that deployment and not of the pairing.
Closes#3855.
A CA that signs exactly two things -- the store's server certificate and
the client certificate of whoever reads from it -- and distributes
nothing. Not the hive CA, not the swarm CA: the store will distribute
both, and an authority you must already hold a certificate from cannot
be one the store hands out. Not the gateway's HTTPS material either,
self-signed or ACME; that is a different trust domain with a different
audience.
The minting lives here rather than in swarm-bao.nix because it is an
opinion about where the store's identity comes from -- the most
consequential one available. The service serves what it is handed. A
deployment with a real internal CA drops this file and names its own
paths in serverCertFile / clientCaFile, and nothing in the store
changes. Ordering simplifies too: with the unit and its consumer in one
module, before/requiredBy is internal rather than a cross-module fact.
Idempotent on ABSENCE only. Re-issuing the CA invalidates every client
certificate already trusting it, so a rebuild that refreshed it would
lock out every reader in the swarm at once.
