Crate otel_bootstrap 

One-call OpenTelemetry bootstrap — traces + metrics + logs with OTLP export.

Call init_telemetry at main() before starting the server. Keep the returned TelemetryHandles alive for the duration of the process — dropping them flushes and shuts down both providers.

Configuration is via environment variables per the OpenTelemetry spec:

• OTEL_EXPORTER_OTLP_ENDPOINT (default: http://localhost:4317 for gRPC, http://localhost:4318 for HTTP)
• OTEL_EXPORTER_OTLP_PROTOCOL (grpc or http/protobuf) — selects transport when both features are enabled
• OTEL_EXPORTER_OTLP_TIMEOUT — export timeout in milliseconds (default: 10 000 ms)
• OTEL_SERVICE_NAME (overridden by the service_name argument)
• OTEL_TRACES_SAMPLER / OTEL_TRACES_SAMPLER_ARG (fallback when no explicit sampler is set)

Env var handling: otel-bootstrap vs SDK

Env var	Handled by
OTEL_SERVICE_NAME	otel-bootstrap (falls back to SDK default)
OTEL_TRACES_SAMPLER / OTEL_TRACES_SAMPLER_ARG	otel-bootstrap
OTEL_EXPORTER_OTLP_PROTOCOL	otel-bootstrap
OTEL_EXPORTER_OTLP_ENDPOINT	otel-bootstrap
OTEL_EXPORTER_OTLP_TIMEOUT	otel-bootstrap
OTEL_BSP_MAX_EXPORT_BATCH_SIZE	SDK (batch span processor)
OTEL_METRIC_EXPORT_INTERVAL	SDK (periodic reader)
Per-signal endpoints (OTEL_EXPORTER_OTLP_TRACES_ENDPOINT etc.)	SDK

Re-exports

pub use instrumented_port::Instrumented;

pub use instrumented_port::InstrumentedArc;

pub use log_bridge::PROPAGATED_SPAN_FIELDS;

pub use log_bridge::SpanLogAttrs;

pub use log_bridge::record_span_log_attr;

pub use log_bridge::record_span_log_attr_on;

pub use spanned::Spanned;

pub use spanned::in_span;

Modules

axum_middleware

Axum tower middleware for W3C trace context propagation.

grpc_middleware

Tonic gRPC trace-context propagation, client and server side.

instrumented_port

Generic client-span wrapper for outbound hexagonal port calls.

log_bridge

profiling

span_enrichment

Span enrichment via the EnrichSpan trait.

spanned

Await-safe replacement for the let _guard = span.enter(); pattern.

testing

No-op / testing mode for otel-bootstrap.

Structs

MtlsMaterial

mTLS material for the gRPC transport. Requires the grpc-mtls feature.

Telemetry

Entry point for configuring telemetry via a builder pattern.

TelemetryBuilder

Builder for configuring telemetry options incrementally.

TelemetryHandles

Handles returned by init_telemetry or TelemetryBuilder::init.

Enums

ExportProtocol

OTLP export protocol.

LogFormat

Stdout log encoding installed by TelemetryBuilder.

TraceSampler

Trace sampler configuration.

Functions

axum_layer

Returns a ready-to-use tower::Layer that extracts W3C trace context from incoming HTTP requests, creates a span with standard HTTP semantic-convention attributes, and injects trace context into response headers.

build_resource

Build a Resource enriched with semantic-convention attributes.

grpc_client_layer

Construct the tower Layer that injects the current trace context into outgoing gRPC request metadata.

grpc_server_layer

Construct the tower Layer that extracts trace context from incoming gRPC request metadata and opens a child span.

init_telemetry

Initialise OpenTelemetry traces + metrics with OTLP gRPC export.

init_telemetry_with_sampler

Initialise OpenTelemetry traces + metrics with OTLP gRPC export and an explicit trace sampler.

span_enricher_layer

Construct the tower Layer that calls span_enrichment::EnrichSpan::enrich_span on every request that carries a T extension.