honojs-middleware/packages/otel/src/index.ts

93 lines
3.1 KiB
TypeScript

import type { TracerProvider } from '@opentelemetry/api'
import { SpanKind, SpanStatusCode, trace, context, propagation } from '@opentelemetry/api'
import {
ATTR_HTTP_REQUEST_HEADER,
ATTR_HTTP_REQUEST_METHOD,
ATTR_HTTP_RESPONSE_HEADER,
ATTR_HTTP_RESPONSE_STATUS_CODE,
ATTR_URL_FULL,
ATTR_HTTP_ROUTE,
} from '@opentelemetry/semantic-conventions'
import type { MiddlewareHandler } from 'hono'
import { createMiddleware } from 'hono/factory'
import metadata from '../package.json' with { type: 'json' }
const PACKAGE_NAME = metadata.name
const PACKAGE_VERSION = metadata.version
export type OtelOptions =
| {
augmentSpan?: false
tracerProvider?: TracerProvider
}
| {
augmentSpan: true
}
export const otel = (options: OtelOptions = {}): MiddlewareHandler => {
if (options.augmentSpan) {
return createMiddleware(async (c, next) => {
// eslint-disable-next-line @typescript-eslint/no-confusing-void-expression
const result = await next()
const span = trace.getActiveSpan()
if (span != null) {
const routePath = c.req.routePath
span.setAttribute(ATTR_HTTP_ROUTE, routePath)
span.updateName(`${c.req.method} ${routePath}`)
}
return result
})
}
const tracerProvider = options.tracerProvider ?? trace.getTracerProvider()
const tracer = tracerProvider.getTracer(PACKAGE_NAME, PACKAGE_VERSION)
return createMiddleware(async (c, next) => {
// Handle propagation of trace context from a request using the W3C Trace Context format
let activeContext = context.active()
if (c.req.header('traceparent')) {
activeContext = propagation.extract(context.active(), c.req.header())
}
const routePath = c.req.routePath
await tracer.startActiveSpan(
`${c.req.method} ${c.req.routePath}`,
{
kind: SpanKind.SERVER,
attributes: {
[ATTR_HTTP_REQUEST_METHOD]: c.req.method,
[ATTR_URL_FULL]: c.req.url,
[ATTR_HTTP_ROUTE]: routePath,
},
},
activeContext,
async (span) => {
for (const [name, value] of Object.entries(c.req.header())) {
span.setAttribute(ATTR_HTTP_REQUEST_HEADER(name), value)
}
try {
await next()
// Update the span name and route path now that we have the response
// because the route path may have changed
span.updateName(`${c.req.method} ${c.req.routePath}`)
span.setAttribute(ATTR_HTTP_ROUTE, c.req.routePath)
span.setAttribute(ATTR_HTTP_RESPONSE_STATUS_CODE, c.res.status)
for (const [name, value] of c.res.headers.entries()) {
span.setAttribute(ATTR_HTTP_RESPONSE_HEADER(name), value)
}
if (c.error) {
span.recordException(c.error)
span.setStatus({ code: SpanStatusCode.ERROR, message: String(c.error) })
}
} catch (e) {
if (e instanceof Error) {
span.recordException(e)
}
span.setStatus({ code: SpanStatusCode.ERROR, message: String(e) })
throw e
} finally {
span.end()
}
}
)
})
}