Removes the OTLP span exporter (tracing-opentelemetry, opentelemetry,
opentelemetry_sdk, opentelemetry-otlp) and its transitive tonic/prost/
h2 tree — 56 crates off the build graph, ~3-5 min off a cold build on
the forgejo runner.
The fmt layer (JSON to stdout via tracing-subscriber) is unchanged;
structured logs still reach the Loki collector through kubectl logs,
and /metrics on :9100 still serves Prometheus. Traces were a nice-to-
have that nothing on call was actually reading.
telemetry::init keeps its signature (service_name + TelemetryGuard)
so re-adding OTLP later is a single-module change. k8s manifests drop
the now-unused OTEL_EXPORTER_OTLP_ENDPOINT env var.
New telemetry module wires tracing-subscriber to both a local JSON
fmt layer (keeps kubectl-logs output identical) and an
OpenTelemetry OTLP/gRPC exporter, activated only when
OTEL_EXPORTER_OTLP_ENDPOINT is set. The returned TelemetryGuard
holds the SdkTracerProvider until process shutdown so queued spans
flush before exit.
Both bin targets (worker, hrrr_point_worker) now call
telemetry::init(service_name) at startup; service_name becomes the
OTel service.name attribute so Tempo groups spans per binary.
Tracing instrumentation on the three main work units:
- pipeline::run_chain_step (forecast f01..f18)
- pipeline::run_analysis_step (analysis f00)
- hrrr_points::process_batch (per-QSO point drain)
k8s manifests set OTEL_EXPORTER_OTLP_ENDPOINT to the cluster
collector at otel-collector.observability.svc.cluster.local:4317.
Backend wiring lives in the vntx-infra repo.
