add external log writer (#3201)

---------

Co-authored-by: Thomas Hunter II <tlhunter@datadog.com>

packages/dd-trace/src/config.js

@@ -204,6 +204,17 @@ class Config {
       false
     )
 
+    const DD_OPENAI_LOGS_ENABLED = coalesce(
+      options.openAiLogsEnabled,
+      process.env.DD_OPENAI_LOGS_ENABLED,
+      false
+    )
+
+    const DD_API_KEY = coalesce(
+      process.env.DATADOG_API_KEY,
+      process.env.DD_API_KEY
+    )
+
     const inAWSLambda = process.env.AWS_LAMBDA_FUNCTION_NAME !== undefined
 
     const isDeprecatedGCPFunction = process.env.FUNCTION_NAME !== undefined && process.env.GCP_PROJECT !== undefined
@@ -471,6 +482,8 @@ ken|consumer_?(?:id|key|secret)|sign(?:ed|ature)?|auth(?:entication|orization)?)
 
     this.tracing = !isFalse(DD_TRACING_ENABLED)
     this.dbmPropagationMode = DD_DBM_PROPAGATION_MODE
+    this.openAiLogsEnabled = DD_OPENAI_LOGS_ENABLED
+    this.apiKey = DD_API_KEY
     this.logInjection = isTrue(DD_LOGS_INJECTION)
     this.env = DD_ENV
     this.url = DD_CIVISIBILITY_AGENTLESS_URL ? new URL(DD_CIVISIBILITY_AGENTLESS_URL)

packages/dd-trace/src/external-logger/src/index.js

@@ -0,0 +1,126 @@
+const tracerLogger = require('../../log')// path to require tracer logger
+
+const https = require('https')
+
+class ExternalLogger {
+  // Note: these attribute names match the corresponding entry in the JSON payload.
+  constructor ({
+    ddsource, hostname, service, apiKey, site = 'datadoghq.com', interval = 10000, timeout = 2000, limit = 1000
+  }) {
+    this.ddsource = ddsource
+    this.hostname = hostname
+    this.service = service
+    this.interval = interval
+    this.timeout = timeout
+    this.queue = []
+    this.limit = limit
+    this.endpoint = '/api/v2/logs'
+    this.site = site
+    this.intake = `http-intake.logs.${this.site}`
+    this.headers = {
+      'DD-API-KEY': apiKey,
+      'Content-Type': 'application/json'
+    }
+    this.timer = setInterval(() => {
+      this.flush()
+    }, this.interval).unref()
+
+    tracerLogger.debug(`started log writer to https://${this.intake}${this.endpoint}`)
+  }
+
+  static tagString (tags) {
+    const tagArray = []
+    for (const key in tags) {
+      tagArray.push(key + ':' + tags[key])
+    }
+    return tagArray.join(',')
+  }
+
+  // Parses and enqueues a log
+  log (log, span, tags) {
+    const logTags = ExternalLogger.tagString(tags)
+
+    if (span) {
+      log['dd.trace_id'] = String(span.trace_id)
+      log['dd.span_id'] = String(span.span_id)
+    }
+
+    const payload = {
+      ...log,
+      'timestamp': Date.now(),
+      'hostname': log.hostname || this.hostname,
+      'ddsource': log.ddsource || this.ddsource,
+      'service': log.service || this.service,
+      'ddtags': logTags || undefined
+    }
+
+    this.enqueue(payload)
+  }
+
+  // Enqueues a raw, non-formatted log object
+  enqueue (log) {
+    if (this.queue.length >= this.limit) {
+      this.flush()
+    }
+    this.queue.push(log)
+  }
+
+  shutdown () {
+    clearInterval(this.timer)
+    this.flush()
+  }
+
+  // Flushes logs with optional callback for when the call is complete
+  flush (cb = () => {}) {
+    let logs
+    let numLogs
+    let encodedLogs
+
+    if (!this.queue.length) {
+      setImmediate(() => cb())
+      return
+    }
+
+    try {
+      logs = this.queue
+      this.queue = []
+
+      numLogs = logs.length
+      encodedLogs = JSON.stringify(logs)
+    } catch (error) {
+      tracerLogger.error(`failed to encode ${numLogs} logs`)
+      setImmediate(() => cb(error))
+      return
+    }
+
+    const options = {
+      hostname: this.intake,
+      port: 443,
+      path: this.endpoint,
+      method: 'POST',
+      headers: this.headers,
+      timeout: this.timeout
+    }
+
+    const req = https.request(options, (res) => {
+      tracerLogger.info(`statusCode: ${res.statusCode}`)
+    })
+    req.once('error', (e) => {
+      tracerLogger.error(`failed to send ${numLogs} log(s), with error ${e.message}`)
+      cb(e)
+    })
+    req.write(encodedLogs)
+    req.end()
+    req.once('response', (res) => {
+      if (res.statusCode >= 400) {
+        const error = new Error(`failed to send ${numLogs} logs, received response code ${res.statusCode}`)
+        tracerLogger.error(error.message)
+        cb(error)
+        return
+      }
+      cb()
+    })
+  }
+}
+
+module.exports = ExternalLogger

packages/dd-trace/src/external-logger/test/index.spec.js

@@ -0,0 +1,147 @@
+'use strict'
+
+require('../../../../dd-trace/test/setup/tap')
+const proxyquire = require('proxyquire')
+const { expect } = require('chai')
+const nock = require('nock')
+
+const tracerLogger = require('../../log')
+
+describe('External Logger', () => {
+  let externalLogger
+  let interceptor
+  let errorLog
+
+  beforeEach(() => {
+    errorLog = sinon.spy(tracerLogger, 'error')
+
+    const ExternalLogger = proxyquire('../src', {
+      '../../log': {
+        error: errorLog
+      }
+    })
+
+    externalLogger = new ExternalLogger({
+      ddsource: 'logging_from_space',
+      hostname: 'mac_desktop',
+      apiKey: 'API_KEY_PLACEHOLDER',
+      interval: 10000,
+      timeout: 5000,
+      limit: 10
+    })
+  })
+
+  afterEach(() => {
+    interceptor.done()
+    errorLog.restore()
+  })
+
+  it('should properly encode the log message', (done) => {
+    let request
+    const currentTime = Date.now()
+
+    interceptor = nock('https://http-intake.logs.datadoghq.com:443')
+      .post('/api/v2/logs')
+      .reply((_uri, req, cb) => {
+        request = req
+        cb(null, [202, '{}', { 'Content-Type': 'application/json' }])
+      })
+
+    const span = {
+      service: 'openAi',
+      trace_id: '000001000',
+      span_id: '9999991999'
+    }
+    const tags = {
+      env: 'external_logger',
+      version: '1.2.3',
+      service: 'external'
+    }
+    externalLogger.log({
+      message: 'oh no, something is up',
+      custom: 'field',
+      attribute: 'funky',
+      service: 'outer_space',
+      level: 'info'
+    }, span, tags)
+
+    externalLogger.flush((err) => {
+      try {
+        expect(request[0]).to.have.property('message', 'oh no, something is up')
+        expect(request[0]).to.have.property('custom', 'field')
+        expect(request[0]).to.have.property('attribute', 'funky')
+        expect(request[0]).to.have.property('service', 'outer_space')
+        expect(request[0]).to.have.property('level', 'info')
+        expect(request[0]).to.have.property('dd.trace_id', '000001000')
+        expect(request[0]).to.have.property('dd.span_id', '9999991999')
+        expect(request[0].timestamp).to.be.greaterThanOrEqual(currentTime)
+        expect(request[0]).to.have.property('ddsource', 'logging_from_space')
+        expect(request[0]).to.have.property('ddtags', 'env:external_logger,version:1.2.3,service:external')
+      } catch (e) {
+        done(e)
+        return
+      }
+
+      done(err)
+    })
+  })
+
+  it('should empty the log queue when calling flush', (done) => {
+    interceptor = nock('https://http-intake.logs.datadoghq.com:443')
+      .post('/api/v2/logs')
+      .reply(202, {})
+
+    externalLogger.enqueue({})
+    expect(externalLogger.queue.length).to.equal(1)
+
+    externalLogger.flush((err) => {
+      expect(externalLogger.queue.length).to.equal(0)
+      done(err)
+    })
+  })
+
+  it('tracer logger should handle error response codes from Logs API', (done) => {
+    interceptor = nock('https://http-intake.logs.datadoghq.com:443')
+      .post('/api/v2/logs')
+      .reply(400, {})
+
+    externalLogger.enqueue({})
+    externalLogger.flush((err) => {
+      expect(err).to.be.an.instanceOf(Error)
+      expect(errorLog.getCall(0).args[0]).to.be.equal(
+        'failed to send 1 logs, received response code 400'
+      )
+      done()
+    })
+  })
+
+  it('tracer logger should handle simulated network error', (done) => {
+    interceptor = nock('https://http-intake.logs.datadoghq.com:443')
+      .post('/api/v2/logs')
+      .replyWithError('missing API key')
+
+    externalLogger.enqueue({})
+    externalLogger.flush((err) => {
+      expect(err).to.be.an.instanceOf(Error)
+      expect(errorLog.getCall(0).args[0]).to.be.equal(
+        'failed to send 1 log(s), with error missing API key'
+      )
+      done()
+    })
+  })
+
+  it('causes a flush when exceeding log queue limit', (done) => {
+    const flusher = sinon.stub(externalLogger, 'flush')
+
+    for (let i = 0; i < 10; i++) {
+      externalLogger.enqueue({})
+    }
+    expect(flusher).to.not.have.been.called
+
+    externalLogger.enqueue({})
+    expect(flusher).to.have.been.called
+
+    flusher.restore()
+    done()
+  })
+})