feat: add OTEL_LOG_LEVEL env var

User can now control the log level by means of env var.

Signed-off-by: Naseem <[email protected]>

packages/opentelemetry-core/src/common/ConsoleLogger.ts

@@ -15,10 +15,13 @@
  */
 
 import { Logger } from '@opentelemetry/api';
-import { LogLevel } from './types';
+import { LogLevel, LogLevelStrings } from './types';
 
 export class ConsoleLogger implements Logger {
-  constructor(level: LogLevel = LogLevel.INFO) {
+  constructor(
+    level: LogLevel = LogLevel[process.env.OTEL_LOG_LEVEL as LogLevelStrings] ||
+      LogLevel.INFO
+  ) {
     if (level >= LogLevel.DEBUG) {
       this.debug = (...args) => {
         console.debug(...args);

packages/opentelemetry-core/src/common/types.ts

@@ -22,6 +22,8 @@ export enum LogLevel {
   DEBUG,
 }
 
+export type LogLevelStrings = keyof typeof LogLevel;
+
 /**
  * This interface defines a fallback to read a timeOrigin when it is not available on performance.timeOrigin,
  * this happens for example on Safari Mac

packages/opentelemetry-core/test/common/ConsoleLogger.test.ts

@@ -54,6 +54,7 @@ describe('ConsoleLogger', () => {
     console.info = origInfo;
     console.warn = origWarn;
     console.error = origError;
+    delete process.env.OTEL_LOG_LEVEL;
   });
 
   describe('constructor', () => {
@@ -67,6 +68,19 @@ describe('ConsoleLogger', () => {
       assert.deepStrictEqual(infoCalledArgs, ['info called %s', 'param1']);
     });
 
+    it('should log with environmentally set level', () => {
+      process.env.OTEL_LOG_LEVEL = 'DEBUG';
+      const consoleLogger = new ConsoleLogger();
+      consoleLogger.error('error called');
+      assert.deepStrictEqual(errorCalledArgs, ['error called']);
+      consoleLogger.warn('warn called %s', 'param1');
+      assert.deepStrictEqual(warnCalledArgs, ['warn called %s', 'param1']);
+      consoleLogger.info('info called %s', 'param1');
+      assert.deepStrictEqual(infoCalledArgs, ['info called %s', 'param1']);
+      consoleLogger.debug('debug called %s', 'param1');
+      assert.deepStrictEqual(debugCalledArgs, ['debug called %s', 'param1']);
+    });
+
     it('should log with debug', () => {
       const consoleLogger = new ConsoleLogger(LogLevel.DEBUG);
       consoleLogger.error('error called');