fix: handle empty env vars as undefined (#693)

src/instrument.ts

@@ -19,6 +19,7 @@ import {
   defaultServiceName,
   getEnvArray,
   getEnvBoolean,
+  getNonEmptyEnvVar,
   parseLogLevel,
 } from './utils';
 
@@ -27,13 +28,13 @@ import { startProfiling } from './profiling';
 import { startTracing } from './tracing';
 
 function boot() {
-  const logLevel = parseLogLevel(process.env.OTEL_LOG_LEVEL);
+  const logLevel = parseLogLevel(getNonEmptyEnvVar('OTEL_LOG_LEVEL'));
 
   if (logLevel !== DiagLogLevel.NONE) {
     diag.setLogger(new DiagConsoleLogger(), logLevel);
   }
 
-  if (process.env.SPLUNK_AUTOINSTRUMENT_PACKAGE_NAMES !== undefined) {
+  if (getNonEmptyEnvVar('SPLUNK_AUTOINSTRUMENT_PACKAGE_NAMES') !== undefined) {
     const limitToPackages = getEnvArray(
       'SPLUNK_AUTOINSTRUMENT_PACKAGE_NAMES',
       []

src/metrics/index.ts

@@ -32,6 +32,7 @@ import {
   getEnvBoolean,
   getEnvNumber,
   getEnvValueByPrecedence,
+  getNonEmptyEnvVar,
 } from '../utils';
 import * as util from 'util';
 import { detect as detectResource } from '../resource';
@@ -195,7 +196,7 @@ function createExporters(options: MetricsOptions) {
   if (!areValidExporterTypes(metricExporters)) {
     throw new Error(
       `Invalid value for OTEL_METRICS_EXPORTER env variable: ${util.inspect(
-        process.env.OTEL_METRICS_EXPORTER
+        getNonEmptyEnvVar('OTEL_METRICS_EXPORTER')
       )}. Choose from ${util.inspect(SUPPORTED_EXPORTER_TYPES, {
         compact: true,
       })} or leave undefined.`
@@ -373,11 +374,12 @@ export function _setDefaultOptions(
   options: StartMetricsOptions = {}
 ): MetricsOptions {
   const accessToken =
-    options.accessToken || process.env.SPLUNK_ACCESS_TOKEN || '';
+    options.accessToken || getNonEmptyEnvVar('SPLUNK_ACCESS_TOKEN') || '';
 
-  const endpoint = options.endpoint || process.env.SPLUNK_METRICS_ENDPOINT;
+  const endpoint =
+    options.endpoint || getNonEmptyEnvVar('SPLUNK_METRICS_ENDPOINT');
 
-  const realm = options.realm || process.env.SPLUNK_REALM || '';
+  const realm = options.realm || getNonEmptyEnvVar('SPLUNK_REALM') || '';
 
   if (realm) {
     if (!accessToken) {

src/profiling/index.ts

@@ -21,6 +21,7 @@ import {
   defaultServiceName,
   getEnvBoolean,
   getEnvNumber,
+  getNonEmptyEnvVar,
 } from '../utils';
 import { detect as detectResource } from '../resource';
 import { SemanticResourceAttributes } from '@opentelemetry/semantic-conventions';
@@ -196,15 +197,15 @@ export function _setDefaultOptions(
 ): ProfilingOptions {
   const endpoint =
     options.endpoint ||
-    process.env.SPLUNK_PROFILER_LOGS_ENDPOINT ||
-    process.env.OTEL_EXPORTER_OTLP_ENDPOINT ||
+    getNonEmptyEnvVar('SPLUNK_PROFILER_LOGS_ENDPOINT') ||
+    getNonEmptyEnvVar('OTEL_EXPORTER_OTLP_ENDPOINT') ||
     'http://localhost:4317';
 
   const combinedResource = detectResource();
 
   const serviceName = String(
     options.serviceName ||
-      process.env.OTEL_SERVICE_NAME ||
+      getNonEmptyEnvVar('OTEL_SERVICE_NAME') ||
       combinedResource.attributes[SemanticResourceAttributes.SERVICE_NAME] ||
       defaultServiceName()
   );

src/profiling/utils.ts

@@ -18,6 +18,7 @@ import { gzip } from 'zlib';
 import { promisify } from 'util';
 import * as grpc from '@grpc/grpc-js';
 import { diag } from '@opentelemetry/api';
+import { getNonEmptyEnvVar } from '../utils';
 
 import { perftools } from './proto/profile';
 import type { HeapProfile, RawProfilingData } from './types';
@@ -251,9 +252,9 @@ export function parseEndpoint(endpoint: string): {
   if (endpoint.startsWith('https://')) {
     host = endpoint.substr(8);
     credentials = grpc.credentials.createSsl(
-      maybeReadPath(process.env.OTEL_EXPORTER_OTLP_CERTIFICATE),
-      maybeReadPath(process.env.OTEL_EXPORTER_OTLP_CLIENT_KEY),
-      maybeReadPath(process.env.OTEL_EXPORTER_OTLP_CLIENT_CERTIFICATE)
+      maybeReadPath(getNonEmptyEnvVar('OTEL_EXPORTER_OTLP_CERTIFICATE')),
+      maybeReadPath(getNonEmptyEnvVar('OTEL_EXPORTER_OTLP_CLIENT_KEY')),
+      maybeReadPath(getNonEmptyEnvVar('OTEL_EXPORTER_OTLP_CLIENT_CERTIFICATE'))
     );
   } else if (endpoint.startsWith('http://')) {
     host = endpoint.substr(7);

src/start.ts

@@ -15,6 +15,7 @@
  */
 import {
   assertNoExtraneousProperties,
+  getNonEmptyEnvVar,
   parseEnvBooleanString,
   parseLogLevel,
   toDiagLogLevel,
@@ -25,7 +26,7 @@ import {
   StartProfilingOptions,
   _setDefaultOptions as setDefaultProfilingOptions,
 } from './profiling';
-import type { LogLevel } from './types';
+import type { EnvVarKey, LogLevel } from './types';
 import { startTracing, stopTracing, StartTracingOptions } from './tracing';
 import { diag, DiagConsoleLogger, DiagLogLevel } from '@opentelemetry/api';
 
@@ -54,10 +55,10 @@ const running: RunningState = {
 
 function isSignalEnabled<T>(
   option: T | undefined | null,
-  envVar: string,
+  envVar: EnvVarKey,
   def: boolean
 ) {
-  return option ?? parseEnvBooleanString(process.env[envVar]) ?? def;
+  return option ?? parseEnvBooleanString(getNonEmptyEnvVar(envVar)) ?? def;
 }
 
 export const start = (options: Partial<Options> = {}) => {
@@ -75,7 +76,7 @@ export const start = (options: Partial<Options> = {}) => {
 
   const logLevel = options.logLevel
     ? toDiagLogLevel(options.logLevel)
-    : parseLogLevel(process.env.OTEL_LOG_LEVEL);
+    : parseLogLevel(getNonEmptyEnvVar('OTEL_LOG_LEVEL'));
 
   if (logLevel !== DiagLogLevel.NONE) {
     diag.setLogger(new DiagConsoleLogger(), logLevel);

src/tracing/index.ts

@@ -36,7 +36,11 @@ import { configureHttpInstrumentation } from '../instrumentations/http';
 import { configureLogInjection } from '../instrumentations/logging';
 import { allowedTracingOptions, Options, _setDefaultOptions } from './options';
 import { configureRedisInstrumentation } from '../instrumentations/redis';
-import { assertNoExtraneousProperties, parseEnvBooleanString } from '../utils';
+import {
+  assertNoExtraneousProperties,
+  getNonEmptyEnvVar,
+  parseEnvBooleanString,
+} from '../utils';
 import { isProfilingContextManagerSet } from '../profiling';
 
 /**
@@ -48,7 +52,7 @@ import { isProfilingContextManagerSet } from '../profiling';
  * leaks and is inperfect in terms of the end result.
  */
 const allowDoubleStart = parseEnvBooleanString(
-  process.env.TEST_ALLOW_DOUBLE_START
+  getNonEmptyEnvVar('TEST_ALLOW_DOUBLE_START')
 );
 let isStarted = false;
 let tracingContextManagerEnabled = false;

src/tracing/options.ts

@@ -33,6 +33,7 @@ import {
   getEnvArray,
   getEnvBoolean,
   getEnvValueByPrecedence,
+  getNonEmptyEnvVar,
 } from '../utils';
 import { NodeTracerConfig } from '@opentelemetry/sdk-trace-node';
 import { SemanticResourceAttributes } from '@opentelemetry/semantic-conventions';
@@ -89,14 +90,14 @@ export const allowedTracingOptions = [
 
 export function _setDefaultOptions(options: Partial<Options> = {}): Options {
   process.env.OTEL_SPAN_LINK_COUNT_LIMIT =
-    process.env.OTEL_SPAN_LINK_COUNT_LIMIT ?? '1000';
+    getNonEmptyEnvVar('OTEL_SPAN_LINK_COUNT_LIMIT') ?? '1000';
   process.env.OTEL_ATTRIBUTE_VALUE_LENGTH_LIMIT =
-    process.env.OTEL_ATTRIBUTE_VALUE_LENGTH_LIMIT ?? '12000';
+    getNonEmptyEnvVar('OTEL_ATTRIBUTE_VALUE_LENGTH_LIMIT') ?? '12000';
 
   options.accessToken =
-    options.accessToken || process.env.SPLUNK_ACCESS_TOKEN || '';
+    options.accessToken || getNonEmptyEnvVar('SPLUNK_ACCESS_TOKEN') || '';
 
-  options.realm = options.realm || process.env.SPLUNK_REALM;
+  options.realm = options.realm || getNonEmptyEnvVar('SPLUNK_REALM');
 
   if (options.realm) {
     if (!options.accessToken) {
@@ -119,7 +120,7 @@ export function _setDefaultOptions(options: Partial<Options> = {}): Options {
 
   const serviceName =
     options.serviceName ||
-    process.env.OTEL_SERVICE_NAME ||
+    getNonEmptyEnvVar('OTEL_SERVICE_NAME') ||
     resource.attributes[SemanticResourceAttributes.SERVICE_NAME];
 
   if (!serviceName) {
@@ -313,7 +314,7 @@ export function consoleSpanExporterFactory(): SpanExporter {
 // Temporary workaround until https://github.com/open-telemetry/opentelemetry-js/issues/3094 is resolved
 function getBatchSpanProcessorConfig() {
   // OTel uses its own parsed environment, we can just use the default env if the BSP delay is unset.
-  if (process.env.OTEL_BSP_SCHEDULE_DELAY !== undefined) {
+  if (getNonEmptyEnvVar('OTEL_BSP_SCHEDULE_DELAY') !== undefined) {
     return undefined;
   }
 

src/types.ts

@@ -15,3 +15,37 @@
  */
 
 export type LogLevel = 'none' | 'verbose' | 'debug' | 'info' | 'warn' | 'error';
+
+export type EnvVarKey =
+  | 'OTEL_ATTRIBUTE_VALUE_LENGTH_LIMIT'
+  | 'OTEL_BSP_SCHEDULE_DELAY'
+  | 'OTEL_EXPORTER_OTLP_CERTIFICATE'
+  | 'OTEL_EXPORTER_OTLP_CLIENT_CERTIFICATE'
+  | 'OTEL_EXPORTER_OTLP_CLIENT_KEY'
+  | 'OTEL_EXPORTER_OTLP_ENDPOINT'
+  | 'OTEL_EXPORTER_OTLP_METRICS_PROTOCOL'
+  | 'OTEL_EXPORTER_OTLP_PROTOCOL'
+  | 'OTEL_EXPORTER_OTLP_TRACES_ENDPOINT'
+  | 'OTEL_EXPORTER_OTLP_TRACES_PROTOCOL'
+  | 'OTEL_LOG_LEVEL'
+  | 'OTEL_METRIC_EXPORT_INTERVAL'
+  | 'OTEL_METRICS_EXPORTER'
+  | 'OTEL_PROPAGATORS'
+  | 'OTEL_SERVICE_NAME'
+  | 'OTEL_SPAN_LINK_COUNT_LIMIT'
+  | 'OTEL_TRACES_EXPORTER'
+  | 'SPLUNK_ACCESS_TOKEN'
+  | 'SPLUNK_AUTOINSTRUMENT_PACKAGE_NAMES'
+  | 'SPLUNK_METRICS_ENABLED'
+  | 'SPLUNK_METRICS_ENDPOINT'
+  | 'SPLUNK_PROFILER_CALL_STACK_INTERVAL'
+  | 'SPLUNK_PROFILER_ENABLED'
+  | 'SPLUNK_PROFILER_LOGS_ENDPOINT'
+  | 'SPLUNK_PROFILER_MEMORY_ENABLED'
+  | 'SPLUNK_REALM'
+  | 'SPLUNK_REDIS_INCLUDE_COMMAND_ARGS'
+  | 'SPLUNK_RUNTIME_METRICS_COLLECTION_INTERVAL'
+  | 'SPLUNK_RUNTIME_METRICS_ENABLED'
+  | 'SPLUNK_TRACE_RESPONSE_HEADER_ENABLED'
+  | 'SPLUNK_TRACING_ENABLED'
+  | 'TEST_ALLOW_DOUBLE_START';

src/utils.ts

@@ -16,7 +16,7 @@
 
 import { strict as assert } from 'assert';
 import { diag, DiagLogLevel } from '@opentelemetry/api';
-import type { LogLevel } from './types';
+import type { EnvVarKey, LogLevel } from './types';
 import { resolve } from 'path';
 import * as fs from 'fs';
 
@@ -54,6 +54,24 @@ export function defaultServiceName(cache: ConfigCache = configCache): string {
   return findServiceName(cache) || 'unnamed-node-service';
 }
 
+export function getNonEmptyEnvVar(key: EnvVarKey): string | undefined {
+  const value = process.env[key];
+
+  if (value !== undefined) {
+    const trimmed = value.trim();
+    if (trimmed.length === 0) {
+      diag.warn(
+        `Defined, but empty environment variable: '${key}'. The value will be considered as undefined.`
+      );
+      return undefined;
+    }
+
+    return trimmed;
+  }
+
+  return value;
+}
+
 export function parseEnvBooleanString(value?: string) {
   if (typeof value !== 'string') {
     return value;
@@ -72,8 +90,8 @@ export function parseEnvBooleanString(value?: string) {
   throw new Error(`Invalid string representing boolean: ${value}`);
 }
 
-export function getEnvBoolean(key: string, defaultValue = true) {
-  const value = process.env[key];
+export function getEnvBoolean(key: EnvVarKey, defaultValue = true) {
+  const value = getNonEmptyEnvVar(key);
 
   if (value === undefined) {
     return defaultValue;
@@ -86,8 +104,8 @@ export function getEnvBoolean(key: string, defaultValue = true) {
   return true;
 }
 
-export function getEnvNumber(key: string, defaultValue: number): number {
-  const value = process.env[key];
+export function getEnvNumber(key: EnvVarKey, defaultValue: number): number {
+  const value = getNonEmptyEnvVar(key);
 
   if (value === undefined) {
     return defaultValue;
@@ -106,8 +124,8 @@ export function deduplicate(arr: string[]) {
   return [...new Set(arr)];
 }
 
-export function getEnvArray(key: string, defaultValue: string[]): string[] {
-  const value = process.env[key];
+export function getEnvArray(key: EnvVarKey, defaultValue: string[]): string[] {
+  const value = getNonEmptyEnvVar(key);
 
   if (value === undefined) {
     return defaultValue;
@@ -117,11 +135,11 @@ export function getEnvArray(key: string, defaultValue: string[]): string[] {
 }
 
 export function getEnvValueByPrecedence(
-  keys: string[],
+  keys: EnvVarKey[],
   defaultValue?: string
 ): string | undefined {
   for (const key of keys) {
-    const value = process.env[key];
+    const value = getNonEmptyEnvVar(key);
 
     if (value !== undefined) {
       return value;

test/examples/collector.config.yml

@@ -20,7 +20,7 @@ service:
   pipelines:
     traces:
       receivers: [otlp]
-      exporters: [httpsink]
+      exporters: [httpsink, logging/debug]
     logs/profiling:
       receivers: [otlp]
       exporters: [logging/debug]