Previous Dockerfile compiled a 'fn main(){}' placeholder to warm the
dep cache, then was supposed to rebuild with real source — but cargo's
fingerprint wasn't picking up the re-added source after rm -rf, so the
placeholder artefact (~430 KB) was what got COPY'd into runtime.
Replace the stub-then-real dance with a single cache-mounted build.
BuildKit persists /usr/local/cargo/registry + git + /src/target across
runs, so dep changes are the only full-rebuild trigger. Copy the real
binary into /usr/local/bin/worker before the COPY --from= in runtime
because COPY --from= can't read from a cache mount.
wgrib2 isn't in Debian apt on trixie — the main prop Dockerfile builds
it from source in a dedicated stage. Rather than duplicate that 5-min
compile in the Rust image's CI path, copy the already-built
/usr/local/bin/wgrib2 + /usr/local/lib/libg2c.so* out of the published
Elixir image.
Also add the libgfortran5/libaec0/zlib1g/libpng16-16t64/libopenjp2-7
runtime deps that wgrib2 links dynamically against — same set the
Elixir runtime installs.
The previous approach (`docker run -v $(pwd)/rust/prop_grid_rs:/src`)
fails under act_runner because the runner container's pwd isn't a path
the host docker daemon can see — clippy installed, then cargo couldn't
find Cargo.toml.
Move the lint + test gate into the Dockerfile builder stage so the
build context ships over the socket the normal way. If clippy warns or
a test regresses, the image build fails and nothing is pushed.
Extracts the memory-hostile HRRR fetch → decode → score pipeline for
forecast hours 1–18 into a separate Rust service (`prop-grid-rs`).
Elixir retains f00 with its native-duct + NEXRAD + commercial-link
enrichment; Rust handles the other 18 steps per hourly chain.
Hand-off via a new `grid_tasks` table (`FOR UPDATE SKIP LOCKED` claim
from Rust, Postgrex `NOTIFY propagation_ready` back to Elixir). Rust
writes the same on-disk score-grid format Elixir already uses, to the
same `/data/scores` NFS tree. Phase 1 ships in shadow mode with
PROP_SCORES_DIR=/data/scores_shadow.
Rust crate layout at `rust/prop_grid_rs/` (1:1 module parity with the
Elixir source it ports):
- grid, region, band_config, scores_file, sounding_params
- scorer: all 10 factors + composite. Matches the Elixir scorer
byte-for-byte across 115 golden-fixture samples (5 scenarios
× 23 bands).
- decoder: wgrib2 subprocess + Fortran-record lola-binary parser
- fetcher: HRRR URL derivation + idx cache (1h TTL) + 8-way
parallel byte-range downloads with 429/5xx retry
- pipeline: end-to-end chain step, f00 rejected at the boundary
- db: sqlx grid_tasks claim/complete + propagation_ready NOTIFY
- bin/worker: tokio main loop, JSON logs, SIGTERM-safe
91 Rust tests + clippy -D warnings clean. 2,158 Elixir tests green.
Elixir additions:
- `GridTaskEnqueuer` seeds fh=1..18 rows from
`PropagationGridWorker.seed_chain/0`
- `NotifyListener` LISTEN → warm `ScoreCache` → PubSub fan-out
- `ShadowComparator` diffs prod vs shadow `.ntms` bodies
- `mix rust.golden` task writes the Rust-side golden fixture
k8s: new `deployment-grid-rs.yaml` pinned to talos5 (32 GB NUC) via
`prop-grid-rs=primary` nodeSelector + `workload=grid-rs:NoSchedule`
toleration, 512 Mi limit, sharing the existing NFS `/data` mount.
The plan document is at `plans/vivid-hatching-quail.md` (local to my
workstation); phases 2 (cutover) and 3 (talos5 concurrency tuning)
follow after 72h of shadow-mode parity.
