implement configuration support

lib/config/default.js

@@ -147,6 +147,47 @@ defaultConfig.definition = () => ({
     formatter: boolean,
     default: true
   },
+
+  /**
+   * Collects configuration related to New Relic Agent Control, i.e. centralized
+   * agent management in container based environments.
+   */
+  agent_control: {
+    /**
+     * If set, must be a GUID string. Indicates that the agent is being managed
+     * by Agent Control. Must be set to enable health monitoring.
+     */
+    fleet_id: {
+      env: 'NEW_RELIC_AGENT_CONTROL_FLEET_ID',
+      default: null
+    },
+
+    /**
+     * Settings specific to the health monitoring aspect of Agent Control.
+     */
+    health: {
+      /**
+       * A string file path to a directory that the agent is expected to write
+       * health status files to. Must be set for health monitoring to be
+       * enabled.
+       */
+      delivery_location: {
+        env: 'NEW_RELIC_AGENT_CONTROL_HEALTH_DELIVERY_LOCATION',
+        default: null
+      },
+
+      /**
+       * The time, in seconds, that the agent should wait between writing
+       * updates to its health status. The default interval is 5 seconds.
+       */
+      frequency: {
+        env: 'NEW_RELIC_AGENT_CONTROL_HEALTH_FREQUENCY',
+        formatter: int,
+        default: 5
+      }
+    }
+  },
+
   /**
    * The default Apdex tolerating / threshold value for applications, in
    * seconds. The default for Node is apdexT to 100 milliseconds, which is

lib/health-reporter.js

@@ -70,10 +70,14 @@ class HealthReporter {
   // STATUS_INTERNAL errors are the Node.js Agent specific error codes.
   static STATUS_INTERNAL_UNEXPECTED_ERROR = 'NR-APM-300'
 
-  constructor({ logger = defaultLogger, setInterval = global.setInterval } = {}) {
-    const fleetId = process.env.NEW_RELIC_SUPERAGENT_FLEET_ID
-    const outDir = process.env.NEW_RELIC_SUPERAGENT_HEALTH_DELIVERY_LOCATION
-    let checkInterval = process.env.NEW_RELIC_SUPERAGENT_HEALTH_FREQUENCY
+  constructor({
+    agentConfig = { agent_control: { health: {} } },
+    logger = defaultLogger,
+    setInterval = global.setInterval
+  } = {}) {
+    const fleetId = agentConfig.agent_control?.fleet_id
+    const outDir = agentConfig.agent_control?.health?.delivery_location
+    let checkInterval = agentConfig.agent_control?.health?.frequency
 
     this.#logger = logger
 
@@ -168,7 +172,8 @@ class HealthReporter {
    */
   stop(done) {
     if (this.#enabled === false) {
-      return done()
+      done && done()
+      return
     }
 
     clearInterval(this.#interval)

package.json

@@ -195,7 +195,8 @@
     "newrelic-naming-rules": "./bin/test-naming-rules.js"
   },
   "imports": {
-    "#agentlib/*.js": "./lib/*.js"
+    "#agentlib/*.js": "./lib/*.js",
+    "#test/assert": "./test/lib/custom-assertions/index.js"
   },
   "dependencies": {
     "@grpc/grpc-js": "^1.12.2",

test/unit/config/config.test.js

@@ -85,6 +85,55 @@ test('when loading options via constructor', async (t) => {
   })
 })
 
+test('agent control', async t => {
+  await t.test('loads defaults', () => {
+    const config = Config.initialize({})
+    assert.deepStrictEqual(config.agent_control, {
+      fleet_id: null,
+      health: {
+        delivery_location: null,
+        frequency: 5
+      }
+    })
+  })
+
+  await t.test('loads from env', () => {
+    process.env.NEW_RELIC_AGENT_CONTROL_FLEET_ID = 42
+    process.env.NEW_RELIC_AGENT_CONTROL_HEALTH_DELIVERY_LOCATION = 'file://find/me'
+    process.env.NEW_RELIC_AGENT_CONTROL_HEALTH_FREQUENCY = 1
+    const config = Config.initialize({})
+    delete process.env.NEW_RELIC_AGENT_CONTROL_FLEET_ID
+    delete process.env.NEW_RELIC_AGENT_CONTROL_HEALTH_DELIVERY_LOCATION
+    delete process.env.NEW_RELIC_AGENT_CONTROL_HEALTH_FREQUENCY
+    assert.deepStrictEqual(config.agent_control, {
+      fleet_id: '42',
+      health: {
+        delivery_location: 'file://find/me',
+        frequency: 1
+      }
+    })
+  })
+
+  await t.test('loads from provided config', () => {
+    const config = Config.initialize({
+      agent_control: {
+        fleet_id: 'from-config',
+        health: {
+          delivery_location: 'file://find/me',
+          frequency: 10
+        }
+      }
+    })
+    assert.deepStrictEqual(config.agent_control, {
+      fleet_id: 'from-config',
+      health: {
+        delivery_location: 'file://find/me',
+        frequency: 10
+      }
+    })
+  })
+})
+
 test('#publicSettings', async (t) => {
   let configuration
 

test/unit/lib/health-reporter.test.js

@@ -11,7 +11,8 @@ const os = require('node:os')
 const fs = require('node:fs')
 const tspl = require('@matteo.collina/tspl')
 
-const match = require('../../lib/custom-assertions/match')
+const { match } = require('#test/assert')
+const Config = require('#agentlib/config/index.js')
 const HealthReporter = require('#agentlib/health-reporter.js')
 
 function simpleInterval(method) {
@@ -54,21 +55,24 @@ test.beforeEach((ctx) => {
     }
   }
 
-  process.env.NEW_RELIC_SUPERAGENT_FLEET_ID = 42
-  process.env.NEW_RELIC_SUPERAGENT_HEALTH_DELIVERY_LOCATION = os.tmpdir()
-  process.env.NEW_RELIC_SUPERAGENT_HEALTH_FREQUENCY = 1
+  ctx.nr.agentConfig = Config.initialize({
+    agent_control: {
+      fleet_id: 42,
+      health: {
+        delivery_location: os.tmpdir(),
+        frequency: 1
+      }
+    }
+  })
 })
 
 test.afterEach((ctx) => {
   fs.writeFile = ctx.nr.writeFileOrig
   process.hrtime.bigint = ctx.nr.bigintOrig
-  delete process.env.NEW_RELIC_SUPERAGENT_FLEET_ID
-  delete process.env.NEW_RELIC_SUPERAGENT_HEALTH_DELIVERY_LOCATION
-  delete process.env.NEW_RELIC_SUPERAGENT_HEALTH_FREQUENCY
 })
 
 test('requires fleet id to be set', (t) => {
-  delete process.env.NEW_RELIC_SUPERAGENT_FLEET_ID
+  delete t.nr.agentConfig.agent_control.fleet_id
 
   const reporter = new HealthReporter(t.nr)
   assert.ok(reporter)
@@ -80,7 +84,7 @@ test('requires fleet id to be set', (t) => {
 })
 
 test('requires output directory to be set', (t) => {
-  delete process.env.NEW_RELIC_SUPERAGENT_HEALTH_DELIVERY_LOCATION
+  delete t.nr.agentConfig.agent_control.health.delivery_location
 
   const reporter = new HealthReporter(t.nr)
   assert.ok(reporter)
@@ -95,7 +99,7 @@ test('requires output directory to be set', (t) => {
 })
 
 test('sets default interval', (t) => {
-  delete process.env.NEW_RELIC_SUPERAGENT_HEALTH_FREQUENCY
+  delete t.nr.agentConfig.agent_control.health.frequency
 
   const reporter = new HealthReporter(t.nr)
   assert.ok(reporter)
@@ -170,7 +174,7 @@ test('logs error if writing failed', async (t) => {
 })
 
 test('setStatus and stop do nothing if reporter disabled', (t, end) => {
-  delete process.env.NEW_RELIC_SUPERAGENT_FLEET_ID
+  delete t.nr.agentConfig.agent_control.fleet_id
   fs.writeFile = () => {
     assert.fail('should not be invoked')
   }