feat: added supportability metrics to indicate how agent was loaded a…

…nd if --enable-source-maps was passed to Node.js runtime (#1657)

 * `Supportability/Features/CJS/Preload` - recorded if `-r newrelic` was used to load agent
 * `Supportability/Features/CJS/Require` - recorded if `require('newrelic')` was used to load agent
 * `Supportability/Features/EnableSourceMaps` - recorded if `node --enable-source-maps` was present to start application

index.js

@@ -15,6 +15,7 @@ require('./lib/util/unwrapped-core')
 const featureFlags = require('./lib/feature_flags').prerelease
 const psemver = require('./lib/util/process-version')
 let logger = require('./lib/logger') // Gets re-loaded after initialization.
+const NAMES = require('./lib/metrics/names')
 
 const pkgJSON = require('./package.json')
 logger.info(
@@ -173,10 +174,30 @@ function createAgent(config) {
 }
 
 function addStartupSupportabilities(agent) {
-  // TODO: As new versions come out, make sure to update Angler metrics.
+  recordLoaderMetric(agent)
+  recordNodeVersionMetric(agent)
+  recordFeatureFlagMetrics(agent)
+  recordSourceMapMetric(agent)
+}
+
+/**
+ * Records the major version of the Node.js runtime
+ * TODO: As new versions come out, make sure to update Angler metrics.
+ *
+ * @param {Agent} agent active NR agent
+ */
+function recordNodeVersionMetric(agent) {
   const nodeMajor = /^v?(\d+)/.exec(process.version)
-  agent.recordSupportability('Nodejs/Version/' + ((nodeMajor && nodeMajor[1]) || 'unknown'))
+  const version = (nodeMajor && nodeMajor[1]) || 'unknown'
+  agent.recordSupportability(`Nodejs/Version/${version}`)
+}
 
+/**
+ * Records all the feature flags configured and if they are enabled/disabled
+ *
+ * @param {Agent} agent active NR agent
+ */
+function recordFeatureFlagMetrics(agent) {
   const configFlags = Object.keys(agent.config.feature_flag)
   for (let i = 0; i < configFlags.length; ++i) {
     const flag = configFlags[i]
@@ -189,3 +210,42 @@ function addStartupSupportabilities(agent) {
     }
   }
 }
+
+/**
+ * Used to determine how the agent is getting loaded:
+ *  1. -r newrelic
+ *  2. --loader newrelic/esm-loader.mjs
+ *  3. require('newrelic')
+ *
+ *  Then a supportability metric is loaded to decide.
+ *  Note: We already take care of scenario #2 in newrelic/esm-loader.mjs
+ *
+ * @param {Agent} agent active NR agent
+ */
+function recordLoaderMetric(agent) {
+  const isESM = agent.metrics.getMetric(NAMES.FEATURES.ESM.LOADER)
+  let isDashR = false
+
+  process.execArgv.forEach((arg, index) => {
+    if (arg === '-r' && process.execArgv[index + 1] === 'newrelic') {
+      agent.metrics.getOrCreateMetric(NAMES.FEATURES.CJS.PRELOAD).incrementCallCount()
+      isDashR = true
+    }
+  })
+
+  if (!isESM && !isDashR) {
+    agent.metrics.getOrCreateMetric(NAMES.FEATURES.CJS.REQUIRE).incrementCallCount()
+  }
+}
+
+/**
+ * Checks to see if `--enable-source-maps` is being used and logs a supportability metric.
+ *
+ * @param {Agent} agent active NR agent
+ */
+function recordSourceMapMetric(agent) {
+  const isSourceMapsEnabled = process.execArgv.includes('--enable-source-maps')
+  if (isSourceMapsEnabled) {
+    agent.metrics.getOrCreateMetric(NAMES.FEATURES.SOURCE_MAPS).incrementCallCount()
+  }
+}

lib/metrics/names.js

@@ -275,6 +275,11 @@ const FEATURES = {
     UNSUPPORTED_LOADER: `${SUPPORTABILITY.FEATURES}/ESM/UnsupportedLoader`,
     CUSTOM_INSTRUMENTATION: `${SUPPORTABILITY.FEATURES}/ESM/CustomInstrumentation`
   },
+  CJS: {
+    PRELOAD: `${SUPPORTABILITY.FEATURES}/CJS/Preload`,
+    REQUIRE: `${SUPPORTABILITY.FEATURES}/CJS/Require`
+  },
+  SOURCE_MAPS: `${SUPPORTABILITY.FEATURES}/EnableSourceMaps`,
   CERTIFICATES: SUPPORTABILITY.FEATURES + '/Certificates',
   INSTRUMENTATION: {
     ON_RESOLVED: SUPPORTABILITY.FEATURES + '/Instrumentation/OnResolved',

test/unit/index.test.js

@@ -0,0 +1,127 @@
+/*
+ * Copyright 2023 New Relic Corporation. All rights reserved.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+'use strict'
+
+const tap = require('tap')
+const proxyquire = require('proxyquire')
+const sinon = require('sinon')
+
+tap.test('loader metrics', (t) => {
+  t.autoend()
+  let metricsMock
+  let MockAgent
+  let shimmerMock
+  let ApiMock
+  let sandbox
+
+  t.beforeEach(() => {
+    sandbox = sinon.createSandbox()
+    metricsMock = require('./mocks/metrics')(sandbox)
+    MockAgent = require('./mocks/agent')(sandbox, metricsMock)
+    shimmerMock = require('./mocks/shimmer')(sandbox)
+
+    ApiMock = function (agent) {
+      this.agent = agent
+    }
+  })
+
+  t.afterEach(() => {
+    process.execArgv = []
+    sandbox.restore()
+    delete require.cache.__NR_cache
+  })
+
+  t.test('should load preload metric when agent is loaded via -r', (t) => {
+    process.execArgv = ['-r', 'newrelic']
+    const agent = proxyquire('../../index', {
+      './lib/agent': MockAgent,
+      './lib/shimmer': shimmerMock,
+      './api': ApiMock
+    })
+
+    const metricCall = agent.agent.metrics.getOrCreateMetric
+
+    t.equal(metricCall.args.length, 1)
+    t.equal(metricCall.args[0][0], 'Supportability/Features/CJS/Preload')
+    t.end()
+  })
+
+  t.test('should not load preload metric if -r is present but is not newrelic', (t) => {
+    process.execArgv = ['-r', 'some-cool-lib']
+    const agent = proxyquire('../../index', {
+      './lib/agent': MockAgent,
+      './lib/shimmer': shimmerMock,
+      './api': ApiMock
+    })
+
+    const metricCall = agent.agent.metrics.getOrCreateMetric
+
+    t.equal(metricCall.args.length, 1)
+    t.equal(metricCall.args[0][0], 'Supportability/Features/CJS/Require')
+    t.end()
+  })
+
+  t.test(
+    'should detect preload metric if newrelic is one of the -r calls but not the first',
+    (t) => {
+      process.execArgv = ['-r', 'some-cool-lib', '--inspect', '-r', 'newrelic']
+      const agent = proxyquire('../../index', {
+        './lib/agent': MockAgent,
+        './lib/shimmer': shimmerMock,
+        './api': ApiMock
+      })
+
+      const metricCall = agent.agent.metrics.getOrCreateMetric
+
+      t.equal(metricCall.args.length, 1)
+      t.equal(metricCall.args[0][0], 'Supportability/Features/CJS/Preload')
+      t.end()
+    }
+  )
+
+  t.test('should not load preload nor require metric is esm loader loads agent', (t) => {
+    metricsMock.getMetric.withArgs('Supportability/Features/ESM/Loader').returns(true)
+    const agent = proxyquire('../../index', {
+      './lib/agent': MockAgent,
+      './lib/shimmer': shimmerMock,
+      './api': ApiMock
+    })
+
+    const metricCall = agent.agent.metrics.getOrCreateMetric
+
+    t.equal(metricCall.args.length, 0)
+    t.end()
+  })
+
+  t.test('should load require metric when agent is required', (t) => {
+    const agent = proxyquire('../../index', {
+      './lib/agent': MockAgent,
+      './lib/shimmer': shimmerMock,
+      './api': ApiMock
+    })
+
+    const metricCall = agent.agent.metrics.getOrCreateMetric
+
+    t.equal(metricCall.args.length, 1)
+    t.equal(metricCall.args[0][0], 'Supportability/Features/CJS/Require')
+    t.end()
+  })
+
+  t.test('should load enable source map metric when --enable-source-maps is present', (t) => {
+    process.execArgv = ['--enable-source-maps']
+    const agent = proxyquire('../../index', {
+      './lib/agent': MockAgent,
+      './lib/shimmer': shimmerMock,
+      './api': ApiMock
+    })
+
+    const metricCall = agent.agent.metrics.getOrCreateMetric
+
+    t.equal(metricCall.args.length, 2)
+    t.equal(metricCall.args[1][0], 'Supportability/Features/EnableSourceMaps')
+    t.end()
+  })
+})

test/unit/mocks/agent.js

@@ -0,0 +1,18 @@
+/*
+ * Copyright 2023 New Relic Corporation. All rights reserved.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+'use strict'
+const sinon = require('sinon')
+module.exports = (sandbox = sinon, metricsMock) => {
+  function MockAgent(config) {
+    this.config = config
+    this.config.app_name = 'Unit Test App'
+    this.metrics = metricsMock
+  }
+  MockAgent.prototype.start = sandbox.stub()
+  MockAgent.prototype.recordSupportability = sandbox.stub()
+  MockAgent.prototype.once = sandbox.stub()
+  return MockAgent
+}

test/unit/mocks/metrics.js

@@ -0,0 +1,13 @@
+/*
+ * Copyright 2023 New Relic Corporation. All rights reserved.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+'use strict'
+const sinon = require('sinon')
+module.exports = (sandbox = sinon) => {
+  return {
+    getMetric: sandbox.stub(),
+    getOrCreateMetric: sandbox.stub().returns({ incrementCallCount: sandbox.stub() })
+  }
+}

test/unit/mocks/shimmer.js

@@ -0,0 +1,14 @@
+/*
+ * Copyright 2023 New Relic Corporation. All rights reserved.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+'use strict'
+const sinon = require('sinon')
+module.exports = (sandbox = sinon) => {
+  return {
+    patchModule: sandbox.stub(),
+    bootstrapInstrumentation: sandbox.stub(),
+    registeredInstrumentations: {}
+  }
+}