Files
seaweedfs/seaweed-worker
1df8c05bc3 rust volume: document every unsafe block and stop mutating the process env in tests (#11352)
Three production `unsafe` blocks carried no `// SAFETY:` comment at all
(`libc::fallocate`, `libc::sysinfo`, `libc::statvfs`), and nothing made
that an error: `clippy::undocumented_unsafe_blocks` is a `restriction`
lint, allow-by-default, and appeared nowhere in either crate. Turn it on
in `seaweed-volume`'s `[lints.clippy]` and in the worker workspace's
`[workspace.lints.clippy]`, then document what each block relies on.

`memory_status.rs` and `disk_location.rs` get their blocks narrowed to
the `zeroed()` and the libc call, so each comment sits next to the
operation it justifies and the arithmetic is outside the block. Both
turn the success test into an early return on failure; the casts, the
multiplication order and the values returned on either path are
unchanged.

The bigger problem was in `config.rs`'s tests. `with_temp_env_var` and
`with_cleared_security_env` called `std::env::set_var`/`remove_var`,
claiming soundness because every caller holds `process_state_lock()`.
That mutex only serialises the fourteen annotated tests in this module.
The same lib test binary runs the `grpc_server.rs` tests, which bind a
`TcpListener`, dial loopback and drive a multi-thread tokio runtime, and
tonic/hyper/rustls/aws-sdk all read the environment lazily on those
threads — which is exactly the race Rust 2024 made these calls unsafe
for. `restore_env_var` had no SAFETY comment at all. `#[serial]` would
not have helped: it serialises annotated tests, which the mutex already
did.

So the config layer no longer reads the environment implicitly. An
`EnvLookup<'a> = &'a dyn Fn(&str) -> Option<OsString>` is threaded from
the public entry points down to every reader — `HOME`, `USERPROFILE`,
the twenty-four `WEED_*` keys and `SEAWEED_WRITE_QUEUE`. `parse_cli` and
`parse_security_config` keep their signatures and pass `process_env`, a
thin wrapper over `std::env::var_os`; `resolve_config` becomes
`resolve_config_with_env` (private, one caller). Tests build one with
`fake_env` instead, so no test touches the real environment and every
`unsafe` in the module is gone.

`process_state_lock()` stays, with a smaller job: `set_current_dir` is
safe but still process-global, so the tests that move the working
directory are still serialised against the ones that read it. Tests
naming an explicit config file never reach that search and no longer
take the lock.

No production behaviour changes: the same keys are read in the same
order with the same precedence, and `env_string` reproduces
`std::env::var(key).ok()` — absent and non-UTF-8 both read as unset.

Co-authored-by: Claude Fable 5.1 <noreply@anthropic.com>
2026-09-20 13:29:07 -07:00
..

SeaweedFS Rust workers

weed/pb/plugin.proto is a language-agnostic contract: a maintenance worker connects out to admin, announces the job types it can detect and execute, and answers requests on that one stream. weed worker -admin=host:23646 is the Go implementation of it from outside the admin process. This workspace is the Rust one.

crates/core     the contract: stream, handshake, heartbeat, registry, config forms
crates/lance    maintenance jobs for Lance tables, and a binary

core knows nothing about any job. A second worker is a new crate beside lance that depends on it, not a fork of the protocol.

Building

Requires Rust 1.94.1+ (2024 edition), matching rust-version in Cargo.toml. The patch release matters: 1.94.0 does not build. The edition itself only needs 1.85; the higher floor comes from the dependency tree — lance's aws feature pulls in the AWS SDK — so it moves with those crates. CI builds on the latest stable.

core compiles plugin.proto with the protoc that protoc-bin-vendored ships, the way seaweed-volume does, so it needs no system install.

The lance crates compile protos of their own, in their own build-script processes, which nothing our build script sets can reach. They need a protoc of their own: either one on PATH — brew install protobuf, apt install protobuf-compiler — or PROTOC naming one. CI points it at the vendored binary for the runner's platform, resolved from the version in Cargo.lock.

Running

cargo run -p weed-lance-worker -- --admin 127.0.0.1:23646

The admin's HTTP address is what an operator has; the gRPC port is derived from it the way the Go side does. Dialling the HTTP port fails as "frame with invalid size", which reads like a protocol bug rather than a wrong port.

The binary is weed-worker, not weed-lance-worker: it is the Rust side of weed worker, and lance is the first family of jobs it carries rather than the only one it ever will.

Released builds do not need a toolchain. The worker ships inside the SeaweedFS image, beside the Rust volume server, under the verb that mirrors volume-rust:

docker run chrislusf/seaweedfs worker-rust --admin admin:23646

and as weed-worker_linux_{amd64,arm64}.tar.gz on each GitHub release. Both are linux amd64/arm64 only — lance, arrow and datafusion make every extra target an expensive build, and the worker runs beside the cluster it maintains. On an architecture without a build the image carries an empty placeholder and the entrypoint says so rather than failing as "not found".

Metrics

cargo run -p weed-lance-worker -- --admin 127.0.0.1:23646 --metrics-port 9328

Serves /health, /ready and /metrics on that port, the same three the Go worker serves under weed worker -metricsPort, so one scrape config covers workers in either language. Off by default, and bound to loopback unless --metrics-ip says otherwise, because the endpoint is unauthenticated. 9328 continues the series the other components use (master 9324, volume 9325, filer 9326, s3 9327); an IPv6 address works with or without brackets.

Grafana: the "Plugin Workers" row of other/metrics/grafana_seaweedfs.json graphs these. Its panels filter on $cluster, which comes from the scrape job's labels, so scrape the worker the way the rest of the cluster is scraped or the row stays empty.

Names are SeaweedFS_worker_*, matching the Go side's convention. The pair worth alerting on is objects_seen_total and objects_skipped_total: a sweep that proposes nothing and a sweep that could read nothing look identical from proposals_total alone.

SeaweedFS_worker_connected 1
SeaweedFS_worker_objects_seen_total{job_type="lance_compact"} 7
SeaweedFS_worker_proposals_total{job_type="lance_compact"} 2
SeaweedFS_worker_jobs_total{job_type="lance_compact",result="ok"} 2
SeaweedFS_worker_lance_fragments_removed_total 25

/ready follows the control stream: a worker whose admin has gone away is running but is not going to do anything.

Credentials

The worker holds none. It asks the namespace to describe a table with vend_credentials and hands the storage_options that come back to lance. A gateway without STS configured vends no credentials at all, so --access-key and --secret-key supply a fallback; anything the namespace does vend wins over them.

State

All three jobs are implemented and tested end to end against a live gateway:

compaction result: 12 fragments became 1
reindex result:    512 uncovered rows became 0
cleanup result:    removed 14 versions and 24272 bytes

cargo test -p weed-lance-worker runs them when WEED_LANCE_NAMESPACE names a live namespace and skips otherwise, the way the Go integration tests skip without Docker. Each test seeds the table it needs, including building a vector index and then appending rows outside it, so a run does not depend on what the previous one left behind — the first version of these did, and quietly stopped testing anything once it had done its job.

The handshake, descriptor exchange and heartbeat work against a live admin, which logs the worker connecting and prefetches all three descriptors.