Detect version metadata binding, add attributes (#120)

* Detect version metadata binding, add attributes

* Export isVersionMetadata

* Rename attribute to script_version

.changeset/hot-dodos-burn.md

@@ -0,0 +1,5 @@
+---
+"@microlabs/otel-cf-workers": patch
+---
+
+Add version metadata to attributes if found

src/instrumentation/env.ts

@@ -27,6 +27,10 @@ const isServiceBinding = (item?: unknown): item is Fetcher => {
 	return !!binding.connect || !!binding.fetch || binding.queue || binding.scheduled
 }
 
+export const isVersionMetadata = (item?: unknown): item is WorkerVersionMetadata => {
+	return !!(item as WorkerVersionMetadata).id && !!(item as WorkerVersionMetadata).tag
+}
+
 const isAnalyticsEngineDataset = (item?: unknown): item is AnalyticsEngineDataset => {
 	return !!(item as AnalyticsEngineDataset)?.writeDataPoint
 }
@@ -49,6 +53,9 @@ const instrumentEnv = (env: Record<string, unknown>): Record<string, unknown> =>
 				return instrumentDOBinding(item, String(prop))
 			} else if (isServiceBinding(item)) {
 				return instrumentServiceBinding(item, String(prop))
+			} else if (isVersionMetadata(item)) {
+				// we do not need to log accesses to the metadata
+				return item
 			} else if (isAnalyticsEngineDataset(item)) {
 				return instrumentAnalyticsEngineDataset(item, String(prop))
 			} else {

src/instrumentation/fetch.ts

@@ -15,6 +15,7 @@ import { instrumentEnv } from './env.js'
 import { exportSpans, proxyExecutionContext } from './common.js'
 import { ResolvedTraceConfig } from '../types.js'
 import { ReadableSpan } from '@opentelemetry/sdk-trace-base'
+import { versionAttributes } from './version.js'
 
 export type IncludeTraceContextFn = (request: Request) => boolean
 export interface FetcherConfig {
@@ -140,6 +141,7 @@ export function executeFetchHandler(fetchFn: FetchHandler, [request, env, ctx]:
 	cold_start = false
 	Object.assign(attributes, gatherRequestAttributes(request))
 	Object.assign(attributes, gatherIncomingCfAttributes(request))
+	Object.assign(attributes, versionAttributes(env))
 	const options: SpanOptions = {
 		attributes,
 		kind: SpanKind.SERVER,

src/instrumentation/queue.ts

@@ -4,6 +4,7 @@ import { Initialiser, setConfig } from '../config.js'
 import { exportSpans, proxyExecutionContext } from './common.js'
 import { instrumentEnv } from './env.js'
 import { unwrap, wrap } from '../wrap.js'
+import { versionAttributes } from './version.js'
 
 type QueueHandler = ExportedHandlerQueueHandler<unknown, unknown>
 export type QueueHandlerArgs = Parameters<QueueHandler>
@@ -141,6 +142,7 @@ export function executeQueueHandler(queueFn: QueueHandler, [batch, env, ctx]: Qu
 		},
 		kind: SpanKind.CONSUMER,
 	}
+	Object.assign(options.attributes!, versionAttributes(env))
 	const promise = tracer.startActiveSpan(`queueHandler:${batch.queue}`, options, async (span) => {
 		const traceId = span.spanContext().traceId
 		api_context.active().setValue(traceIdSymbol, traceId)

src/instrumentation/scheduled.ts

@@ -4,6 +4,7 @@ import { Initialiser, setConfig } from '../config.js'
 import { exportSpans, proxyExecutionContext } from './common.js'
 import { instrumentEnv } from './env.js'
 import { wrap } from '../wrap.js'
+import { versionAttributes } from './version.js'
 
 type ScheduledHandler = ExportedHandlerScheduledHandler<unknown>
 export type ScheduledHandlerArgs = Parameters<ScheduledHandler>
@@ -23,6 +24,7 @@ export function executeScheduledHandler(
 		[SemanticAttributes.FAAS_TIME]: new Date(controller.scheduledTime).toISOString(),
 	}
 	cold_start = false
+	Object.assign(attributes, versionAttributes(env))
 	const options: SpanOptions = {
 		attributes,
 		kind: SpanKind.SERVER,

src/instrumentation/version.ts

@@ -0,0 +1,19 @@
+import { isVersionMetadata } from './env.js'
+
+export function versionAttributes(env: unknown): Record<string, string | undefined> {
+	const attributes = {} as Record<string, string | undefined>
+
+	if (typeof env === 'object' && env !== null) {
+		for (const [binding, data] of Object.entries(env)) {
+			if (isVersionMetadata(data)) {
+				attributes['cf.script_version.binding'] = binding
+				attributes['cf.script_version.id'] = data.id
+				attributes['cf.script_version.tag'] = data.tag
+				// Version metadata bindings are identical, so we can stop after the first one found
+				break
+			}
+		}
+	}
+
+	return attributes
+}