Crate krabka_telemetry 

Generic OTLP distributed-tracing pipeline for Krabka services.

The consuming service always installs a structured-JSON tracing_subscriber fmt layer. That layer writes to stdout and uses the usual RUST_LOG EnvFilter. Container log collectors such as GKE / Cloud Logging and Loki thus ingest each line as fields, not as ANSI-coloured human text.

The environment can also configure OTLP export. This crate then attaches a second tracing-opentelemetry layer, which converts tracing spans into OpenTelemetry spans. That layer batch-exports the spans over OTLP to a collector: gRPC :4317 or HTTP/protobuf :4318.

Enabling

OTLP is off by default. A service with no OTLP environment keeps its behavior byte-for-byte. OTLP turns on when one of these variables sets an endpoint: KRABKA_OTLP_ENDPOINT, OTEL_EXPORTER_OTLP_TRACES_ENDPOINT, or OTEL_EXPORTER_OTLP_ENDPOINT. KRABKA_OTLP_ENABLED=true also turns OTLP on. OTEL_SDK_DISABLED=true turns OTLP off and overrides the other variables.

WebAssembly

On wasm32-wasip1 the crate has no OTLP exporter and no profiling admin server, because both need a network client stack or a socket bind. There, init returns TelemetryError::Unsupported for an OTLP configuration and installs nothing, and profiling exports only its configuration types.

Resolve OTLP settings without touching the environment

use krabka_telemetry::{OtlpConfig, OtlpProtocol};

let cfg = OtlpConfig::from_env(
    |key| (key == "KRABKA_OTLP_ENABLED").then(|| "true".to_string()),
    "broker-1",
    "0.1.0",
    "krabka-broker",
)
.expect("valid OTLP configuration")
.expect("OTLP enabled");

assert2::assert!((cfg.protocol) == (OtlpProtocol::Grpc));
assert2::assert!((cfg.endpoint) == ("http://localhost:4317"));

Re-exports

pub use krabka_trace_context as propagation;

Modules

profiling

In-process profiling admin server.

Structs

LogLevelController

The handle that reads and retargets the live log filter.

LogLevelFilter

The [Filter] side of a LogLevelController.

OtlpConfig

Resolved OTLP configuration.

TelemetryGuard

Owns the OTLP SdkTracerProvider, so shutdown flushes the spans.

Enums

LogLevel

One level in Kafka’s BROKER_LOGGER vocabulary.

OtlpProtocol

OTLP transport.

TelemetryError

An error from the build of the OTLP pipeline.

Constants

ROOT_LOGGER

The name log4j2 and Kafka both give the level every unmatched target falls back to. kafka-configs prints it beside the real loggers.

VALID_LOG_LEVELS

The level names a BROKER_LOGGER value may carry, in the order Kafka renders them into its rejection message.

Functions

init

Install the global tracing subscriber.