feat: first pass at d1 support

.changeset/brown-cobras-whisper.md

@@ -0,0 +1,5 @@
+---
+'@microlabs/otel-cf-workers': minor
+---
+
+Add initial support for D1 (experimental)

src/instrumentation/d1.ts

@@ -0,0 +1,157 @@
+import { Attributes, SpanKind, SpanOptions, SpanStatusCode, Exception, trace } from '@opentelemetry/api'
+import { SemanticAttributes } from '@opentelemetry/semantic-conventions'
+import { wrap } from '../wrap.js'
+
+const dbSystem = 'Cloudflare D1'
+
+// We need to peak into D1 "internals" to instrument batch queries
+// See: https://github.com/cloudflare/workerd/blob/5d27f8f7f1f9b584f673d2f11c9032f5a776ec55/src/cloudflare/internal/d1-api.ts#L173
+interface D1StatementInternals {
+	statement: string
+	params: unknown[]
+}
+
+function metaAttributes(meta: D1Meta): Attributes {
+	return {
+		'db.cf.d1.rows_read': meta.rows_read,
+		'db.cf.d1.rows_written': meta.rows_written,
+		'db.cf.d1.duration': meta.duration,
+		'db.cf.d1.size_after': meta.size_after,
+		'db.cf.d1.last_row_id': meta.last_row_id,
+		'db.cf.d1.changed_db': meta.changed_db,
+		'db.cf.d1.changes': meta.changes,
+	}
+}
+function spanOptions(dbName: string, operation: string, sql?: string): SpanOptions {
+	const attributes: Attributes = {
+		binding_type: 'D1',
+		[SemanticAttributes.DB_NAME]: dbName,
+		[SemanticAttributes.DB_SYSTEM]: dbSystem,
+		[SemanticAttributes.DB_OPERATION]: operation,
+	}
+	if (sql) {
+		attributes[SemanticAttributes.DB_STATEMENT] = sql
+	}
+	return {
+		kind: SpanKind.CLIENT,
+		attributes,
+	}
+}
+
+function instrumentD1StatementFn(fn: Function, dbName: string, operation: string, sql: string) {
+	const tracer = trace.getTracer('D1')
+	const fnHandler: ProxyHandler<any> = {
+		apply: (target, thisArg, argArray) => {
+			if (operation === 'bind') {
+				const newStmt = Reflect.apply(target, thisArg, argArray) as D1PreparedStatement
+				return instrumentD1PreparedStatement(newStmt, dbName, sql)
+			}
+
+			const options = spanOptions(dbName, operation, sql)
+			return tracer.startActiveSpan(`${dbName} ${operation}`, options, async (span) => {
+				try {
+					const result = await Reflect.apply(target, thisArg, argArray)
+					if (operation === 'all' || operation === 'run') {
+						span.setAttributes(metaAttributes((result as D1Result).meta))
+					}
+					span.setStatus({ code: SpanStatusCode.OK })
+					return result
+				} catch (error) {
+					span.recordException(error as Exception)
+					span.setStatus({ code: SpanStatusCode.ERROR })
+					throw error
+				} finally {
+					span.end()
+				}
+			})
+		},
+	}
+	return wrap(fn, fnHandler)
+}
+
+function instrumentD1PreparedStatement(
+	stmt: D1PreparedStatement,
+	dbName: string,
+	statement: string,
+): D1PreparedStatement {
+	const statementHandler: ProxyHandler<D1PreparedStatement> = {
+		get: (target, prop, receiver) => {
+			const operation = String(prop)
+			const fn = Reflect.get(target, prop, receiver)
+			if (typeof fn === 'function') {
+				return instrumentD1StatementFn(fn, dbName, operation, statement)
+			}
+			return fn
+		},
+	}
+	return wrap(stmt, statementHandler)
+}
+
+export function instrumentD1Fn(fn: Function, dbName: string, operation: string) {
+	const tracer = trace.getTracer('D1')
+	const fnHandler: ProxyHandler<any> = {
+		apply: (target, thisArg, argArray) => {
+			if (operation === 'prepare') {
+				const sql = argArray[0] as string
+				const stmt = Reflect.apply(target, thisArg, argArray) as D1PreparedStatement
+				return instrumentD1PreparedStatement(stmt, dbName, sql)
+			} else if (operation === 'exec') {
+				const sql = argArray[0] as string
+				const options = spanOptions(dbName, operation, sql)
+				return tracer.startActiveSpan(`${dbName} ${operation}`, options, async (span) => {
+					try {
+						const result = await Reflect.apply(target, thisArg, argArray)
+						span.setStatus({ code: SpanStatusCode.OK })
+						return result
+					} catch (error) {
+						span.recordException(error as Exception)
+						span.setStatus({ code: SpanStatusCode.ERROR })
+						throw error
+					} finally {
+						span.end()
+					}
+				})
+			} else if (operation === 'batch') {
+				// Create span for each statement, requires peeaking into D1 internals ...
+				const statements = argArray[0] as D1StatementInternals[]
+				return tracer.startActiveSpan(`${dbName} ${operation}`, async (span) => {
+					// Create a span per query in the batch
+					const subSpans = statements.map((s) =>
+						tracer.startSpan(`${dbName} ${operation} > query`, spanOptions(dbName, operation, s.statement)),
+					)
+
+					try {
+						const result = (await Reflect.apply(target, thisArg, argArray)) as D1Result[]
+						result.forEach((r, i) => subSpans[i]?.setAttributes(metaAttributes(r.meta)))
+						span.setStatus({ code: SpanStatusCode.OK })
+						return result
+					} catch (error) {
+						span.recordException(error as Exception)
+						span.setStatus({ code: SpanStatusCode.ERROR })
+						throw error
+					} finally {
+						subSpans.forEach((s) => s.end())
+						span.end()
+					}
+				})
+			} else {
+				return Reflect.apply(target, thisArg, argArray)
+			}
+		},
+	}
+	return wrap(fn, fnHandler)
+}
+
+export function instrumentD1(database: D1Database, dbName: string): D1Database {
+	const dbHandler: ProxyHandler<D1Database> = {
+		get: (target, prop, receiver) => {
+			const operation = String(prop)
+			const fn = Reflect.get(target, prop, receiver)
+			if (typeof fn === 'function') {
+				return instrumentD1Fn(fn, dbName, operation)
+			}
+			return fn
+		},
+	}
+	return wrap(database, dbHandler)
+}

src/instrumentation/env.ts

@@ -3,6 +3,7 @@ import { instrumentDOBinding } from './do.js'
 import { instrumentKV } from './kv.js'
 import { instrumentQueueSender } from './queue.js'
 import { instrumentServiceBinding } from './service.js'
+import { instrumentD1 } from './d1'
 import { instrumentAnalyticsEngineDataset } from './analytics-engine.js'
 
 const isJSRPC = (item?: unknown): item is Service => {
@@ -34,6 +35,10 @@ const isAnalyticsEngineDataset = (item?: unknown): item is AnalyticsEngineDatase
 	return !isJSRPC(item) && !!(item as AnalyticsEngineDataset)?.writeDataPoint
 }
 
+const isD1Database = (item?: unknown): item is D1Database => {
+	return !!(item as D1Database)?.exec && !!(item as D1Database)?.prepare
+}
+
 const instrumentEnv = (env: Record<string, unknown>): Record<string, unknown> => {
 	const envHandler: ProxyHandler<Record<string, unknown>> = {
 		get: (target, prop, receiver) => {
@@ -54,6 +59,8 @@ const instrumentEnv = (env: Record<string, unknown>): Record<string, unknown> =>
 				return item
 			} else if (isAnalyticsEngineDataset(item)) {
 				return instrumentAnalyticsEngineDataset(item, String(prop))
+			} else if (isD1Database(item)) {
+				return instrumentD1(item, String(prop))
 			} else {
 				return item
 			}