The live pair was replaced with two renames, key then cert. A run
stopped between them (timeout, container stop, power loss) left a new
key beside the old cert, and every later run logged in with that pair,
so the agent could not re-pull until its container restarted.
Each pair now goes into a fresh directory under
/run/hive-agent-bao-identity, and `current`, a symlink to it, is
replaced by one rename. Wherever a run stops, `current` names one whole
pair; the next run removes whatever a stopped run left. Consumers read
`current/cert` and `current/key` through the same read-only options and
still re-read them on every login.
The script test covers a swap stopped at each of its link and rename
steps: the live pair is always one whole pair, and the next run puts
the new one live.
Refs #5017
swarm-controller re-issues an agent's store leaf at half its validity, but
the running container kept presenting the copy its hive delivered at
start, so a re-issued leaf reached the agent only on its next restart.
hive-agent-bao-identity now seeds a live copy of the pair in its own
runtime directory from the delivered credentials, and re-runs every 10
minutes: it logs in with the live leaf, reads its own
swarm/agents/<agent>/bao-mtls (a read render_agent already grants), and
when the leaf changed, logs in with the new pair and swaps it in only if
the store accepts it.
Every unit in the container that logs in to the store presents the live
pair: hive-agent (queue-identity.nix), hive-matrix-daemon,
hive-subagent-daemon, hive-agent-forge-token, hive-agent-forge-accounts
and hive-agent-github-token. They keep loading the server CA as a
credential. The long-running daemons are ordered after the refresher so
the live pair exists when they start.
It renews only while the held leaf is still valid: the login that reads
the new leaf is made with the current one.
Refs #5017
Six credential-fetch units retried 4 times at 15s, so an apply during
which the store or gateway was down for more than about a minute left
them in start-limit-hit, and nothing started them again once the store
came back. The swarm-services leaf could also land after nginx had
already given up on it, and the hook that propagates a new leaf only
reloaded a running nginx, so a stopped one stayed down until a second
apply.
- nix/host-modules/lib/store-retry.nix: the 2880 x 30s / 25h window
shape swarm-services-cert already had, as one attrset.
- swarm-services-cert, swarm-bao-otel-oidc, swarm-bao-forwarder-oidc,
swarm-bao-matrix-token, swarm-bao-queue-agent, swarm-bao-grafana-oidc,
hive-agent-bao-identity and hive-agent-forge-token use it.
queue-identity.nix no longer has a fetch unit (ccb5bd3b), and
forge-token.nix is a fetch unit with the same short budget that was
added after the census in #4662.
- The swarm-services-cert propagation hook now reset-fails and starts
(--no-block) a loaded nginx that is not active; an active nginx keeps
the re-import + reload.
- module-eval-bao-grants: one case pinning the shape on every host-side
fetch unit, swarm-services-cert included.
Refs #4662
`swarm-controller` mints an agent's mTLS leaf at creation and publishes it
at `swarm/agents/<agent>/bao-mtls`. Nothing read it back. This adds the
hop that carries it the rest of the way, and the in-container consumer
that proves the hop works.
Host side, `lifecycle::agent_identity` reads the row under *this hive's*
own certificate — the hive is a principal the store already knows — and
stages the leaf and its key `0600` under a new `agent-identity/<name>`
state dir, deliberately outside every bind-mounted tree. Both files go in
as systemd credentials rather than binds, the same answer and the same
mode reason as the queue secret beside it: the staged key is unreadable
to the unprivileged agent user, and the container manager reads a
`--load-credential` source as root before re-exposing it under the
consuming unit's own `User=`. The agent is never asked to authenticate in
order to obtain the thing it authenticates with.
Container side, `hive-agent-bao-identity.service` logs in with that
certificate and reads the agent's own path back, failing the unit when
either step does not succeed. It fails loudly where the hive-side readers
degrade quietly, because a refused certificate means an agent that
believes it reaches the store and never does — a cause only the login
itself can name.
The address is the whole switch, no separate `enable`, matching how
`queue.nix` and `logs.nix` already gate themselves. A hive with a store
forwards `HIVE_AGENT_BAO_ADDR` and every agent on it gets the check; a
hive without one forwards nothing and no agent does. That is what keeps
the delivery from landing in a container with nothing to read it.
The hive can now reach an agent's identity, so hive privilege covers
agent privilege. Accepted, not mitigated: the alternative is an agent
fetching its own credential with a credential it does not yet have.
Refs #4137
