feat: metadata.system.{configured_hostname,detected_hostname}, prefer FQDN for host.name ECS field (#3437)

Author: trentm

CHANGELOG.asciidoc

@@ -64,6 +64,11 @@ recent versions of node v12-v18. ESM support will remain experimental while the
 https://nodejs.org/api/esm.html#loaders[Node.js Loaders API] is experimental.
 See <<esm>> for full details.
 
+* Send `configured_hostname` and `detected_hostname` metadata separately,
+  rather than the old deprecated single `hostname` metadatum. As well, the
+  detected hostname now attempts to collect a FQDN to be used in the
+  `host.name` field in the Elasticsearch document. ({issues}3310[#3310])
+
 [float]
 ===== Bug fixes
 

lib/apm-client/http-apm-client.js

@@ -38,7 +38,7 @@ function getHttpClientConfig (conf, agent) {
     frameworkName: conf.frameworkName,
     frameworkVersion: conf.frameworkVersion,
     globalLabels: maybePairsToObject(conf.globalLabels),
-    hostname: conf.hostname,
+    configuredHostname: conf.hostname,
     environment: conf.environment,
 
     // Sanitize conf

lib/instrumentation/modules/http2.js

@@ -65,7 +65,7 @@ module.exports = function (http2, agent, { enabled }) {
         const tracestate = headers.tracestate
         const trans = agent.startTransaction(null, 'request', {
           childOf: traceparent,
-          tracestate: tracestate
+          tracestate
         })
         // `trans.req` and `trans.res` are fake representations of Node.js's
         // core `http.IncomingMessage` and `http.ServerResponse` objects,

package-lock.json

@@ -95,7 +95,7 @@
     "basic-auth": "^2.0.1",
     "cookie": "^0.5.0",
     "core-util-is": "^1.0.2",
-    "elastic-apm-http-client": "11.4.0",
+    "elastic-apm-http-client": "12.0.0",
     "end-of-stream": "^1.4.4",
     "error-callsites": "^2.0.4",
     "error-stack-parser": "^2.0.6",

package.json

@@ -65,8 +65,8 @@ function assertMetadata (t, payload) {
     'metadata: service.agent')
 
   const system = Object.assign({}, payload.system)
-  t.strictEqual(system.hostname, os.hostname(), 'metadata: system.hostname')
-  delete system.hostname
+  t.ok(system.detected_hostname.startsWith(os.hostname()), 'metadata: system.detected_hostname')
+  delete system.detected_hostname
   t.strictEqual(system.architecture, process.arch, 'metadata: system.architecture')
   delete system.architecture
   t.strictEqual(system.platform, process.platform, 'metadata: system.platform')