feat: custom fetcher

README.md

@@ -264,6 +264,33 @@ const config: ResolveConfigFn = (env: Env, trigger) => ({
 - Both tracing and logging
 - Neither (no telemetry)
 
+### Custom Fetcher
+
+```typescript
+const config: ResolveConfigFn = (env: Env, trigger) => {
+	const { fetch } = env.VPC_BINDING
+	const fetcher = fetch.bind(env.VPC_BINDING)
+	return {
+		service: {
+			name: 'my-service',
+			version: '1.0.0', // Optional
+			namespace: 'production', // Optional
+		},
+		trace: {
+			exporter: {
+				fetcher,
+				url: env.TRACE_ENDPOINT,
+				headers: { 'signoz-access-token': env.SIGNOZ_ACCESS_TOKEN },
+			},
+		},
+		// Logs are optional
+		logs: {
+			transports: [new OTLPTransport({ fetcher, url: env.LOGS_ENDPOINT })],
+		},
+	}
+}
+```
+
 ### Sampling
 
 ```typescript

src/exporter.ts

@@ -8,14 +8,17 @@ import { DEFAULT_OTLP_HEADERS } from './constants'
 export interface OTLPExporterConfig {
 	url: string
 	headers?: Record<string, string>
+	fetcher?: Fetcher['fetch']
 }
 
 export class OTLPExporter implements SpanExporter {
 	private headers: Record<string, string>
 	private url: string
+	private fetcher: Fetcher['fetch']
 	constructor(config: OTLPExporterConfig) {
 		this.url = config.url
 		this.headers = Object.assign({}, DEFAULT_OTLP_HEADERS, config.headers)
+		this.fetcher = config.fetcher ?? fetch
 	}
 
 	export(items: any[], resultCallback: (result: ExportResult) => void): void {

src/logs/transport.ts

@@ -37,11 +37,13 @@ export class OTLPTransport implements LogTransport {
 	private headers: Record<string, string>
 	private url: string
 	private minSeverity: number
+	private fetcher: Fetcher['fetch']
 
 	constructor(config: OTLPTransportConfig) {
 		this.url = config.url
 		this.headers = Object.assign({}, DEFAULT_OTLP_HEADERS, config.headers)
 		this.minSeverity = levelToSeverity(config.level ?? 'TRACE')
+		this.fetcher = config.fetcher ?? fetch
 	}
 
 	export(logs: ReadableLogRecord[], callback: ExportResultCallback): void {
@@ -79,7 +81,7 @@ export class OTLPTransport implements LogTransport {
 			body,
 		}
 
-		const response = await unwrap(fetch)(this.url, params)
+		const response = await unwrap(this.fetcher)(this.url, params)
 
 		if (!response.ok) {
 			throw new OTLPExporterError(`Exporter received a statusCode: ${response.status}`)

src/logs/types.ts

@@ -80,6 +80,7 @@ export interface OTLPTransportConfig {
 	url: string
 	headers?: Record<string, string>
 	level?: LogLevel
+	fetcher?: Fetcher['fetch']
 }
 
 export interface ConsoleTransportConfig {