Add Support For Mapping OTEL_LOG_LEVEL='debug' (#4363)

* An OTEL_LOG_LEVEL of debug should also be mapped to  DD_TRACE_DEBUG=true

Author: khanayan123

packages/dd-trace/src/config.js

@@ -170,6 +170,7 @@ class Config {
     // Configure the logger first so it can be used to warn about other configs
     this.debug = isTrue(coalesce(
       process.env.DD_TRACE_DEBUG,
+      process.env.OTEL_LOG_LEVEL && process.env.OTEL_LOG_LEVEL === 'debug',
       false
     ))
     this.logger = options.logger

packages/dd-trace/test/config.spec.js

@@ -77,6 +77,7 @@ describe('Config', () => {
     process.env.DD_SERVICE = 'service'
     process.env.OTEL_SERVICE_NAME = 'otel_service'
     process.env.DD_TRACE_LOG_LEVEL = 'error'
+    process.env.DD_TRACE_DEBUG = 'false'
     process.env.OTEL_LOG_LEVEL = 'debug'
     process.env.DD_TRACE_SAMPLE_RATE = '0.5'
     process.env.OTEL_TRACES_SAMPLER = 'traceidratio'
@@ -93,6 +94,7 @@ describe('Config', () => {
 
     const config = new Config()
 
+    expect(config).to.have.property('debug', false)
     expect(config).to.have.property('service', 'service')
     expect(config).to.have.property('logLevel', 'error')
     expect(config).to.have.property('sampleRate', 0.5)
@@ -109,7 +111,7 @@ describe('Config', () => {
 
   it('should initialize with OTEL environment variables when DD env vars are not set', () => {
     process.env.OTEL_SERVICE_NAME = 'otel_service'
-    process.env.OTEL_LOG_LEVEL = 'warn'
+    process.env.OTEL_LOG_LEVEL = 'debug'
     process.env.OTEL_TRACES_SAMPLER = 'traceidratio'
     process.env.OTEL_TRACES_SAMPLER_ARG = '0.1'
     process.env.OTEL_TRACES_EXPORTER = 'none'
@@ -119,8 +121,9 @@ describe('Config', () => {
 
     const config = new Config()
 
+    expect(config).to.have.property('debug', true)
     expect(config).to.have.property('service', 'otel_service')
-    expect(config).to.have.property('logLevel', 'warn')
+    expect(config).to.have.property('logLevel', 'debug')
     expect(config).to.have.property('sampleRate', 0.1)
     expect(config).to.have.property('runtimeMetrics', false)
     expect(config.tags).to.include({ foo: 'bar1', baz: 'qux1' })