feat(startup-log): report OTLP export status (#9517)

Add three boolean fields to the DATADOG TRACER CONFIGURATION startup log
indicating whether the tracer exports each telemetry signal over OTLP:

- otlp_traces_export_enabled  (OTEL_TRACES_EXPORTER === 'otlp', excluding
  Test Optimization mode, which keeps test spans on the citestcycle endpoint)
- otlp_metrics_export_enabled (DD_METRICS_OTEL_ENABLED)
- otlp_logs_export_enabled    (DD_LOGS_OTEL_ENABLED)

The snake_case keys are chosen for cross-language startup-log consistency.

Author: bm1549

packages/dd-trace/src/startup-log.js

@@ -108,6 +108,9 @@ function configInfo () {
     profiling_enabled: profilingEnabled === 'true' || profilingEnabled === 'auto',
     appsec_enabled: config.appsec.enabled,
     data_streams_enabled: !!config.dsmEnabled,
+    otlp_traces_export_enabled: config.OTEL_TRACES_EXPORTER === 'otlp' && !config.isCiVisibility,
+    otlp_metrics_export_enabled: !!config.DD_METRICS_OTEL_ENABLED,
+    otlp_logs_export_enabled: !!config.DD_LOGS_OTEL_ENABLED,
   }
 }
 

packages/dd-trace/test/startup-log.spec.js

@@ -3,7 +3,7 @@
 const assert = require('node:assert')
 const os = require('node:os')
 
-const { describe, it, before, afterEach } = require('mocha')
+const { describe, it, before, beforeEach, afterEach } = require('mocha')
 const sinon = require('sinon')
 
 require('./setup/core')
@@ -80,6 +80,9 @@ describe('startup logging', () => {
     assert.strictEqual(logObj.debug, true)
     assert.strictEqual(logObj.appsec_enabled, true)
     assert.strictEqual(logObj.data_streams_enabled, true)
+    assert.strictEqual('otlp_traces_export_enabled' in logObj, true)
+    assert.strictEqual('otlp_metrics_export_enabled' in logObj, true)
+    assert.strictEqual('otlp_logs_export_enabled' in logObj, true)
   })
 
   it('logIntegrations should output loaded integrations', () => {
@@ -121,6 +124,9 @@ describe('startup logging', () => {
       integrations_loaded: ['http', 'fs', 'semver'],
       appsec_enabled: true,
       data_streams_enabled: true,
+      otlp_traces_export_enabled: false,
+      otlp_metrics_export_enabled: false,
+      otlp_logs_export_enabled: false,
     })
   })
 })
@@ -314,3 +320,70 @@ describe('profiling_enabled', () => {
     })
   })
 })
+
+describe('otlp export flags', () => {
+  function clearOtlpEnv () {
+    delete process.env.OTEL_TRACES_EXPORTER
+    delete process.env.OTEL_METRICS_EXPORTER
+    delete process.env.OTEL_LOGS_EXPORTER
+    delete process.env.DD_METRICS_OTEL_ENABLED
+    delete process.env.DD_LOGS_OTEL_ENABLED
+  }
+
+  // Datadog-instrumented dev shells export the OTEL_*_EXPORTER selectors: a leaked
+  // OTEL_TRACES_EXPORTER=otlp corrupts the default-state assertion, and OTEL_METRICS_EXPORTER=none
+  // makes config force DD_METRICS_OTEL_ENABLED back to false, breaking the metrics positive case.
+  beforeEach(clearOtlpEnv)
+  afterEach(clearOtlpEnv)
+
+  function startupLogObj (configOptions) {
+    sinon.stub(console, 'warn')
+    delete require.cache[require.resolve('../src/startup-log')]
+    const {
+      setStartupLogConfig,
+      startupLog,
+    } = require('../src/startup-log')
+    process.env.DD_TRACE_STARTUP_LOGS = 'true'
+    setStartupLogConfig(getConfigFresh(configOptions))
+    startupLog()
+    /* eslint-disable-next-line no-console */
+    const warnStub = /** @type {sinon.SinonStub} */ (console.warn)
+    const logObj = JSON.parse(warnStub.firstCall.args[0].replace('DATADOG TRACER CONFIGURATION - ', ''))
+    warnStub.restore()
+    return logObj
+  }
+
+  it('should default to false when no OTLP env vars are set', () => {
+    const logObj = startupLogObj()
+    assert.strictEqual(logObj.otlp_traces_export_enabled, false)
+    assert.strictEqual(logObj.otlp_metrics_export_enabled, false)
+    assert.strictEqual(logObj.otlp_logs_export_enabled, false)
+  })
+
+  it('otlp_traces_export_enabled should be true when OTEL_TRACES_EXPORTER is otlp', () => {
+    process.env.OTEL_TRACES_EXPORTER = 'otlp'
+    assert.strictEqual(startupLogObj().otlp_traces_export_enabled, true)
+  })
+
+  it('otlp_traces_export_enabled should be false when OTEL_TRACES_EXPORTER is none', () => {
+    process.env.OTEL_TRACES_EXPORTER = 'none'
+    assert.strictEqual(startupLogObj().otlp_traces_export_enabled, false)
+  })
+
+  it('otlp_traces_export_enabled should be false in Test Optimization mode even when exporter is otlp', () => {
+    // Test Optimization keeps test spans on the citestcycle endpoint, so the OTLP
+    // trace exporter is not used regardless of OTEL_TRACES_EXPORTER (see opentracing/tracer.js).
+    process.env.OTEL_TRACES_EXPORTER = 'otlp'
+    assert.strictEqual(startupLogObj({ isCiVisibility: true }).otlp_traces_export_enabled, false)
+  })
+
+  it('otlp_metrics_export_enabled should be true when DD_METRICS_OTEL_ENABLED is true', () => {
+    process.env.DD_METRICS_OTEL_ENABLED = 'true'
+    assert.strictEqual(startupLogObj().otlp_metrics_export_enabled, true)
+  })
+
+  it('otlp_logs_export_enabled should be true when DD_LOGS_OTEL_ENABLED is true', () => {
+    process.env.DD_LOGS_OTEL_ENABLED = 'true'
+    assert.strictEqual(startupLogObj().otlp_logs_export_enabled, true)
+  })
+})