Support Hand-Off Config (#5126)

Author: BaptisteFoy

package.json

@@ -82,7 +82,7 @@
     "node": ">=18"
   },
   "dependencies": {
-    "@datadog/libdatadog": "^0.4.0",
+    "@datadog/libdatadog": "^0.5.0",
     "@datadog/native-appsec": "8.4.0",
     "@datadog/native-iast-rewriter": "2.8.0",
     "@datadog/native-iast-taint-tracking": "3.3.0",

packages/dd-trace/src/config.js

@@ -11,7 +11,7 @@ const tagger = require('./tagger')
 const get = require('../../datadog-core/src/utils/src/get')
 const has = require('../../datadog-core/src/utils/src/has')
 const set = require('../../datadog-core/src/utils/src/set')
-const { isTrue, isFalse } = require('./util')
+const { isTrue, isFalse, normalizeProfilingEnabledValue } = require('./util')
 const { GIT_REPOSITORY_URL, GIT_COMMIT_SHA } = require('./plugins/util/tags')
 const { getGitMetadataFromGitProperties, removeUserSensitiveInfo } = require('./git_properties')
 const { updateConfig } = require('./telemetry')
@@ -236,6 +236,12 @@ function reformatSpanSamplingRules (rules) {
 
 class Config {
   constructor (options = {}) {
+    if (!isInServerlessEnvironment()) {
+      // Bail out early if we're in a serverless environment, stable config isn't supported
+      const StableConfig = require('./config_stable')
+      this.stableConfig = new StableConfig()
+    }
+
     options = {
       ...options,
       appsec: options.appsec != null ? options.appsec : options.experimental?.appsec,
@@ -244,13 +250,24 @@ class Config {
 
     // Configure the logger first so it can be used to warn about other configs
     const logConfig = log.getConfig()
-    this.debug = logConfig.enabled
+    this.debug = log.isEnabled(
+      this.stableConfig?.fleetEntries?.DD_TRACE_DEBUG,
+      this.stableConfig?.localEntries?.DD_TRACE_DEBUG
+    )
     this.logger = coalesce(options.logger, logConfig.logger)
-    this.logLevel = coalesce(options.logLevel, logConfig.logLevel)
-
+    this.logLevel = log.getLogLevel(
+      options.logLevel,
+      this.stableConfig?.fleetEntries?.DD_TRACE_LOG_LEVEL,
+      this.stableConfig?.localEntries?.DD_TRACE_LOG_LEVEL
+    )
     log.use(this.logger)
     log.toggle(this.debug, this.logLevel)
 
+    // Process stable config warnings, if any
+    for (const warning of this.stableConfig?.warnings ?? []) {
+      log.warn(warning)
+    }
+
     checkIfBothOtelAndDdEnvVarSet()
 
     const DD_API_KEY = coalesce(
@@ -337,7 +354,9 @@ class Config {
     }
 
     this._applyDefaults()
+    this._applyLocalStableConfig()
     this._applyEnvironment()
+    this._applyFleetStableConfig()
     this._applyOptions(options)
     this._applyCalculated()
     this._applyRemote({})
@@ -576,6 +595,45 @@ class Config {
     this._setValue(defaults, 'trace.dynamoDb.tablePrimaryKeys', undefined)
   }
 
+  _applyLocalStableConfig () {
+    const obj = setHiddenProperty(this, '_localStableConfig', {})
+    this._applyStableConfig(this.stableConfig?.localEntries ?? {}, obj)
+  }
+
+  _applyFleetStableConfig () {
+    const obj = setHiddenProperty(this, '_fleetStableConfig', {})
+    this._applyStableConfig(this.stableConfig?.fleetEntries ?? {}, obj)
+  }
+
+  _applyStableConfig (config, obj) {
+    const {
+      DD_APPSEC_ENABLED,
+      DD_APPSEC_SCA_ENABLED,
+      DD_DATA_STREAMS_ENABLED,
+      DD_DYNAMIC_INSTRUMENTATION_ENABLED,
+      DD_ENV,
+      DD_IAST_ENABLED,
+      DD_LOGS_INJECTION,
+      DD_PROFILING_ENABLED,
+      DD_RUNTIME_METRICS_ENABLED,
+      DD_SERVICE,
+      DD_VERSION
+    } = config
+
+    this._setBoolean(obj, 'appsec.enabled', DD_APPSEC_ENABLED)
+    this._setBoolean(obj, 'appsec.sca.enabled', DD_APPSEC_SCA_ENABLED)
+    this._setBoolean(obj, 'dsmEnabled', DD_DATA_STREAMS_ENABLED)
+    this._setBoolean(obj, 'dynamicInstrumentation.enabled', DD_DYNAMIC_INSTRUMENTATION_ENABLED)
+    this._setString(obj, 'env', DD_ENV)
+    this._setBoolean(obj, 'iast.enabled', DD_IAST_ENABLED)
+    this._setBoolean(obj, 'logInjection', DD_LOGS_INJECTION)
+    const profilingEnabled = normalizeProfilingEnabledValue(DD_PROFILING_ENABLED)
+    this._setString(obj, 'profiling.enabled', profilingEnabled)
+    this._setBoolean(obj, 'runtimeMetrics', DD_RUNTIME_METRICS_ENABLED)
+    this._setString(obj, 'service', DD_SERVICE)
+    this._setString(obj, 'version', DD_VERSION)
+  }
+
   _applyEnvironment () {
     const {
       AWS_LAMBDA_FUNCTION_NAME,
@@ -831,16 +889,13 @@ class Config {
       this._envUnprocessed.peerServiceMapping = DD_TRACE_PEER_SERVICE_MAPPING
     }
     this._setString(env, 'port', DD_TRACE_AGENT_PORT)
-    const profilingEnabledEnv = coalesce(
-      DD_EXPERIMENTAL_PROFILING_ENABLED,
-      DD_PROFILING_ENABLED,
-      this._isInServerlessEnvironment() ? 'false' : undefined
+    const profilingEnabled = normalizeProfilingEnabledValue(
+      coalesce(
+        DD_EXPERIMENTAL_PROFILING_ENABLED,
+        DD_PROFILING_ENABLED,
+        this._isInServerlessEnvironment() ? 'false' : undefined
+      )
     )
-    const profilingEnabled = isTrue(profilingEnabledEnv)
-      ? 'true'
-      : isFalse(profilingEnabledEnv)
-        ? 'false'
-        : profilingEnabledEnv === 'auto' ? 'auto' : undefined
     this._setString(env, 'profiling.enabled', profilingEnabled)
     this._setString(env, 'profiling.exporters', DD_PROFILING_EXPORTERS)
     this._setBoolean(env, 'profiling.sourceMap', DD_PROFILING_SOURCE_MAP && !isFalse(DD_PROFILING_SOURCE_MAP))
@@ -1347,9 +1402,33 @@ class Config {
   // eslint-disable-next-line @stylistic/js/max-len
   // https://github.com/DataDog/dd-go/blob/prod/trace/apps/tracer-telemetry-intake/telemetry-payload/static/config_norm_rules.json
   _merge () {
-    const containers = [this._remote, this._options, this._env, this._calculated, this._defaults]
-    const origins = ['remote_config', 'code', 'env_var', 'calculated', 'default']
-    const unprocessedValues = [this._remoteUnprocessed, this._optsUnprocessed, this._envUnprocessed, {}, {}]
+    const containers = [
+      this._remote,
+      this._options,
+      this._fleetStableConfig,
+      this._env,
+      this._localStableConfig,
+      this._calculated,
+      this._defaults
+    ]
+    const origins = [
+      'remote_config',
+      'code',
+      'fleet_stable_config',
+      'env_var',
+      'local_stable_config',
+      'calculated',
+      'default'
+    ]
+    const unprocessedValues = [
+      this._remoteUnprocessed,
+      this._optsUnprocessed,
+      {},
+      this._envUnprocessed,
+      {},
+      {},
+      {}
+    ]
     const changes = []
 
     for (const name in this._defaults) {

packages/dd-trace/src/config_stable.js

@@ -0,0 +1,100 @@
+const os = require('os')
+const fs = require('fs')
+
+class StableConfig {
+  constructor () {
+    this.warnings = [] // Logger hasn't been initialized yet, so we can't use log.warn
+    this.localEntries = {}
+    this.fleetEntries = {}
+    this.wasm_loaded = false
+
+    const { localConfigPath, fleetConfigPath } = this._getStableConfigPaths()
+    if (!fs.existsSync(localConfigPath) && !fs.existsSync(fleetConfigPath)) {
+      // Bail out early if files don't exist to avoid unnecessary library loading
+      return
+    }
+
+    const localConfig = this._readConfigFromPath(localConfigPath)
+    const fleetConfig = this._readConfigFromPath(fleetConfigPath)
+    if (!localConfig && !fleetConfig) {
+      // Bail out early if files are empty or we can't read them to avoid unnecessary library loading
+      return
+    }
+
+    // Note: we don't enforce loading because there may be cases where the library is not available and we
+    // want to avoid breaking the application. In those cases, we will not have the file-based configuration.
+    let libdatadog
+    try {
+      libdatadog = require('@datadog/libdatadog')
+      this.wasm_loaded = true
+    } catch (e) {
+      this.warnings.push('Can\'t load libdatadog library')
+      return
+    }
+
+    const libconfig = libdatadog.maybeLoad('library_config')
+    if (libconfig === undefined) {
+      this.warnings.push('Can\'t load library_config library')
+      return
+    }
+
+    try {
+      const configurator = new libconfig.JsConfigurator()
+      configurator.set_envp(Object.entries(process.env).map(([key, value]) => `${key}=${value}`))
+      configurator.set_args(process.argv)
+      configurator.get_configuration(localConfig.toString(), fleetConfig.toString()).forEach((entry) => {
+        if (entry.source === 'local_stable_config') {
+          this.localEntries[entry.name] = entry.value
+        } else if (entry.source === 'fleet_stable_config') {
+          this.fleetEntries[entry.name] = entry.value
+        }
+      })
+    } catch (e) {
+      this.warnings.push(`Error parsing configuration from file: ${e.message}`)
+    }
+  }
+
+  _readConfigFromPath (path) {
+    try {
+      return fs.readFileSync(path, 'utf8')
+    } catch (err) {
+      if (err.code !== 'ENOENT') {
+        this.warnings.push(`Error reading config file at ${path}. ${err.code}: ${err.message}`)
+      }
+      return '' // Always return a string to avoid undefined.toString() errors
+    }
+  }
+
+  _getStableConfigPaths () {
+    let localConfigPath = ''
+    let fleetConfigPath = ''
+    switch (os.type().toLowerCase()) {
+      case 'linux':
+        localConfigPath = '/etc/datadog-agent/application_monitoring.yaml'
+        fleetConfigPath = '/etc/datadog-agent/managed/datadog-agent/stable/application_monitoring.yaml'
+        break
+      case 'darwin':
+        localConfigPath = '/opt/datadog-agent/etc/application_monitoring.yaml'
+        fleetConfigPath = '/opt/datadog-agent/etc/managed/datadog-agent/stable/application_monitoring.yaml'
+        break
+      case 'win32':
+        localConfigPath = 'C:\\ProgramData\\Datadog\\application_monitoring.yaml'
+        fleetConfigPath = 'C:\\ProgramData\\Datadog\\managed\\datadog-agent\\stable\\application_monitoring.yaml'
+        break
+      default:
+        break
+    }
+
+    // Allow overriding the paths for testing
+    if (process.env.DD_TEST_LOCAL_CONFIG_PATH !== undefined) {
+      localConfigPath = process.env.DD_TEST_LOCAL_CONFIG_PATH
+    }
+    if (process.env.DD_TEST_FLEET_CONFIG_PATH !== undefined) {
+      fleetConfigPath = process.env.DD_TEST_FLEET_CONFIG_PATH
+    }
+
+    return { localConfigPath, fleetConfigPath }
+  }
+}
+
+module.exports = StableConfig

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

@@ -105,23 +105,36 @@ const log = {
 
   deprecate (code, message) {
     return this._deprecate(code, message)
+  },
+
+  isEnabled (fleetStableConfigValue = undefined, localStableConfigValue = undefined) {
+    return isTrue(coalesce(
+      fleetStableConfigValue,
+      process.env?.DD_TRACE_DEBUG,
+      process.env?.OTEL_LOG_LEVEL === 'debug' || undefined,
+      localStableConfigValue,
+      config.enabled
+    ))
+  },
+
+  getLogLevel (
+    optionsValue = undefined,
+    fleetStableConfigValue = undefined,
+    localStableConfigValue = undefined
+  ) {
+    return coalesce(
+      optionsValue,
+      fleetStableConfigValue,
+      process.env?.DD_TRACE_LOG_LEVEL,
+      process.env?.OTEL_LOG_LEVEL,
+      localStableConfigValue,
+      config.logLevel
+    )
   }
 }
 
 log.reset()
 
-const enabled = isTrue(coalesce(
-  process.env.DD_TRACE_DEBUG,
-  process.env.OTEL_LOG_LEVEL === 'debug',
-  config.enabled
-))
-
-const logLevel = coalesce(
-  process.env.DD_TRACE_LOG_LEVEL,
-  process.env.OTEL_LOG_LEVEL,
-  config.logLevel
-)
-
-log.toggle(enabled, logLevel)
+log.toggle(log.isEnabled(), log.getLogLevel())
 
 module.exports = log

packages/dd-trace/src/util.js

@@ -79,11 +79,20 @@ function hasOwn (object, prop) {
   return Object.prototype.hasOwnProperty.call(object, prop)
 }
 
+function normalizeProfilingEnabledValue (configValue) {
+  return isTrue(configValue)
+    ? 'true'
+    : isFalse(configValue)
+      ? 'false'
+      : configValue === 'auto' ? 'auto' : undefined
+}
+
 module.exports = {
   isTrue,
   isFalse,
   isError,
   globMatch,
   calculateDDBasePath,
-  hasOwn
+  hasOwn,
+  normalizeProfilingEnabledValue
 }