import "https://deno.land/x/xhr@0.1.0/mod.ts"; import "node:async_hooks"; import { context, propagation, SpanStatusCode, trace } from "https://cdn.skypack.dev/@opentelemetry/api"; import { OTLPTraceExporter } from "https://cdn.skypack.dev/@opentelemetry/exporter-trace-otlp-http"; import { B3Propagator } from "https://cdn.skypack.dev/@opentelemetry/propagator-b3"; import { Resource } from "https://cdn.skypack.dev/@opentelemetry/resources"; import { ConsoleSpanExporter, SimpleSpanProcessor, WebTracerProvider, } from "https://cdn.skypack.dev/@opentelemetry/sdk-trace-web"; import { SemanticResourceAttributes } from "https://cdn.skypack.dev/@opentelemetry/semantic-conventions"; import { AsyncLocalStorageContextManager } from "npm:@opentelemetry/context-async-hooks"; export function get_tracer() { return trace.getTracer("valtown"); } /** * Initializes opentelemetry tracing. */ export function init(service_name: string, console_log: bool = false): undefined { const provider = new WebTracerProvider({ resource: new Resource({ [SemanticResourceAttributes.SERVICE_NAME]: service_name, }), }); // Log traces to console if console_log is set. if (console_log) { provider.addSpanProcessor(new SimpleSpanProcessor(new ConsoleSpanExporter())); } // Send traces to honeycomb if HONEYCOMB_API_KEY key is set. const honeycomb_api_key = Deno.env.get("HONEYCOMB_API_KEY"); if (honeycomb_api_key) { provider.addSpanProcessor( new SimpleSpanProcessor( new OTLPTraceExporter({ url: "https://api.honeycomb.io/v1/traces", headers: { "x-honeycomb-team": honeycomb_api_key, }, }), ), ); } provider.register({ contextManager: new AsyncLocalStorageContextManager(), propagator: new B3Propagator(), }); } /** * Wrapper for fetch that traces the request. It also passes a propagation header * so if you are calling another val that uses traced_handler their traces will * be tied together. */ export async function traced_fetch( input: string | URL, init?: RequestInit, ): Promise { return await get_tracer().startActiveSpan(`fetch`, async (span) => { const prop_output: { b3: string } = { b3: "" }; propagation.inject(context.active(), prop_output); try { const resp: Response = await fetch(input, { ...init, headers: { b3: prop_output.b3, ...(init?.headers ?? {}), }, }); span.setAttributes({ "http.url": resp.url, "response.status_code": resp.status, }); if (resp.ok && resp.status >= 200 && resp.status < 400) { span.setStatus({ code: SpanStatusCode.OK }); } else { span.setStatus({ code: SpanStatusCode.ERROR, message: await resp.clone().text(), }); } return resp; } catch (error) { span.setStatus({ code: SpanStatusCode.ERROR, message: error.message, }); throw new Error(error); } finally { span.end(); } }); } /** * Wrapper to trace a function. */ // deno-lint-ignore no-explicit-any export const traced = any>( name: string, fn: F, ) => { return async (...args: Parameters): Promise>> => { return await get_tracer().startActiveSpan(name, async (span) => { try { const result = await fn(...args); if (span.isRecording()) { span.setStatus({ code: SpanStatusCode.OK }); } return result; } catch (error) { if (span.isRecording()) { span.setStatus({ code: SpanStatusCode.ERROR, message: error.message, }); } throw new Error(error); } finally { span.end(); } }); }; }; /** * Takes an http handler and returns a new handler that * traces the request. * @returns {Function} A new handler that traces the request. */ export function traced_handler( handler: (req: Request) => Promise, ): (req: Request) => Promise { async function _traced_hander(req: Request): Promise { let active_context = null; const prop_header = req.headers.get("b3"); if (prop_header) { active_context = propagation.extract(context.active(), { b3: prop_header, }); } return await get_tracer().startActiveSpan( `${req.method} ${req.url}`, {}, active_context, async (span) => { try { const resp: Response = await handler(req); span.setAttributes({ "http.method": req.method, "http.url": req.url, "response.status_code": resp.status, }); if (resp.ok && resp.status >= 200 && resp.status < 400) { span.setStatus({ code: SpanStatusCode.OK }); } else { span.setStatus({ code: SpanStatusCode.ERROR, message: await resp.clone().text(), }); } return resp; } catch (error) { span.setStatus({ code: SpanStatusCode.ERROR, message: error.message, }); throw new Error(error); } finally { span.end(); } }, ); } return _traced_hander; }

tracing

Versions

v0