hyperhive/swarm-logs/README.md
atlas a39399f037 swarm-logs: an agent's CLI for the swarm log store
An agent can reach VictoriaLogs only through the gateway, and since the
machine query route landed the way to read it has been to hand-roll a
client_credentials token request and a curl, per query. This is the CLI
that closes that: `swarm-logs query '<LogsQL>'`, matched log lines on
stdout, so the answer pipes into grep like any other command's.

Built to the plan posted on the tracker thread: own crate, own
docs/tools reference generated off the clap tree, `query` as the one
verb, and the JSON error body surfaced on a non-200 rather than
swallowed. No `tail`: streaming is a different endpoint with a different
response shape, and folding it in here would be a fatter scope than the
ask.

Minting the token is NOT implemented here — swarm-queue-client already
owns the client_credentials request, its error type and its CA handling,
and a token-endpoint fix has to be findable in one place. What this crate
adds is the agent-shaped half: the client id arrives as a *file* beside
the secret, so nothing outside nix/agent-modules/queue.nix spells
`hive-<name>-agent` twice. That is the same problem hive-agent's
swarm_queue module solves, and swarm-logs/src/auth.rs is its `decide`
restated over this binary's inputs.

⚠️ The plan named one thing to verify empirically before calling the auth
settled: whether authelia's bearer policy for the logs vhost accepts the
agent client's audience. Measured from inside a container: it does not.
The client minted a token fine but with `aud: []` and `scp: []`, asking
for the logs URL as an audience answered `invalid_target`, and presenting
the audience-less token to the gateway answered a bare 401. So
swarm-authelia.nix's agentClients gains `authelia.bearer.authz` and the
query URL as a second audience — authelia authorises a bearer token by
the URL being requested, and that URL is now one binding read by three
places rather than three spellings of one address.

The URL reaches an agent the same way its queue coordinates do: computed
on the host (a container cannot derive a gateway address), forwarded by
hive_c0re::meta into the container's option set, and consumed by a new
agent module that installs the binary *wrapped* with its coordinates —
the shape swarm-controller.nix installs swarmctl in. Gated on the queue
credential as well as on the URL: a binary that can only answer 401 is
worse than no binary, because an agent reads a 401 as "no logs", which is
the exact confusion the store's machine route was added to end.
2026-09-17 01:02:14 +02:00

4.6 KiB

swarm-logs

An agent's CLI for the swarm log store. One verb — swarm-logs query '<LogsQL>' — so reading logs pipes and greps like any other command instead of being a hand-rolled token request plus a curl, per query.

Read-only and query-only. There is no ingest path here (that is the collector's), and no tail: streaming is a different LogsQL endpoint with a different response shape, left for a follow-up rather than folded in.

Distinct from hive-metric, the other half of the same surface from an agent's seat: that one writes a custom metric, this one reads logs.

⚠️ There is no scoping

The gateway forwards the query unmodified, so any authenticated caller reads the whole swarm's logs — every hive's, not only its own. That is the rule in force rather than an omission here; when read permissions exist they attach at the gateway location, not in this binary.

How it authenticates

The agent container already holds one identity, the per-hive machine client hive-<name>-agent, delivered as a systemd credential pair. This binary presents a client_credentials access token minted from it as Authorization: Bearer.

Minting is not implemented here — swarm_queue_client::mint_token_for_blocking already owns the request, its error type and its CA handling, and a token-endpoint fix has to be findable in one place. What this crate adds is the agent-shaped half: the client id arrives as a file beside the secret, so nothing outside nix/agent-modules/queue.nix spells hive-<name>-agent twice. That is the same problem hive-agent/src/swarm_queue.rs solves, and src/auth.rs is its decide restated over this binary's inputs.

🩸 Every credential here is a path. The secret's contents are read at the moment of the request, inside swarm-queue-client, and are never bound to a name in this crate, logged, or rendered into an error.

The audience is the URL

swarm-logs mints its token with the query URL as the requested audience, because that is what authelia checks at the authz endpoint the gateway's auth_request calls. The same rule swarm-otel.nix states over its own push targets: one binding for the address and the audience, since two spellings of one address present as a valid token refused at the store.

⚠️ That requires the agent client to be registered for that audience and to hold authelia.bearer.authz. Both are set in swarm-authelia.nix's agentClients; without them authelia answers invalid_target at the token endpoint, or the gateway answers 401 with no explanation.

Configuration

Supplied by nix/agent-modules/logs.nix, which wraps the binary — the same shape swarmctl is configured in, and for the same reason: every value is derived from an option that module owns, so a default here would be an address we hope points at something.

variable what
HIVE_AGENT_LOGS_QUERY_URL the LogsQL query endpoint; also the token's audience
HIVE_AGENT_OIDC_TOKEN_ENDPOINT authelia's token endpoint
HIVE_AGENT_OIDC_CLIENT_ID_FILE path of the delivered client-id credential
HIVE_AGENT_OIDC_CLIENT_SECRET_FILE path of the delivered secret credential
HIVE_AGENT_OIDC_CA_FILE optional extra trust anchor; unset in this tree

HIVE_AGENT, the same prefix the harness reads, because it is the same identity — an agent authenticates as its hive's agent client whether the caller is the harness or a CLI the agent typed. The first four are all-or-none: a half-set environment is a deployment bug, and this binary says so by name rather than behaving like an unconfigured one.

Output

$ swarm-logs query 'atlas-otel-probe' --limit 5

One log message per line by default (the record's _msg), which is what a grep pattern is written against. --format json passes the store's NDJSON through unmodified, for _time, _stream and jq.

A record the projection cannot understand — no string _msg, or not JSON at all — is printed whole rather than dropped. Silently losing a row would make an incomplete answer indistinguishable from a complete one.

A non-200 is reported with its body and a non-zero exit, never as an empty result. That is the whole reason the gateway grew a separate machine route: the operator's browser route answers an unauthenticated caller with authelia's login page as a 200 with an HTML body, and a client that reads only the status code records a query that succeeded and matched nothing.