From 33c57cc84a8b87ad3a58dde2014738deab1c375b Mon Sep 17 00:00:00 2001
From: Matthew Wear <matthew.wear@gmail.com>
Date: Wed, 8 Feb 2023 00:33:46 -0800
Subject: [PATCH] feat(detector-gcp): collect hostname resource attribute from
 GCP Metadata API (#1364)

* feat: collect hostname resource attribute from GCP Metadata API

* chore: remove unneeded changelog entry

---------

Co-authored-by: Amir Blum <amirgiraffe@gmail.com>
---
 .../src/detectors/GcpDetector.ts              | 24 ++++++++++++++-----
 .../test/detectors/GcpDetector.test.ts        | 18 ++++++++++----
 2 files changed, 32 insertions(+), 10 deletions(-)

diff --git a/detectors/node/opentelemetry-resource-detector-gcp/src/detectors/GcpDetector.ts b/detectors/node/opentelemetry-resource-detector-gcp/src/detectors/GcpDetector.ts
index 1d4139d70..080bbc02e 100644
--- a/detectors/node/opentelemetry-resource-detector-gcp/src/detectors/GcpDetector.ts
+++ b/detectors/node/opentelemetry-resource-detector-gcp/src/detectors/GcpDetector.ts
@@ -52,16 +52,19 @@ class GcpDetector implements Detector {
       return Resource.empty();
     }
 
-    const [projectId, instanceId, zoneId, clusterName] = await Promise.all([
-      this._getProjectId(),
-      this._getInstanceId(),
-      this._getZone(),
-      this._getClusterName(),
-    ]);
+    const [projectId, instanceId, zoneId, clusterName, hostname] =
+      await Promise.all([
+        this._getProjectId(),
+        this._getInstanceId(),
+        this._getZone(),
+        this._getClusterName(),
+        this._getHostname(),
+      ]);
 
     const attributes: ResourceAttributes = {};
     attributes[SemanticResourceAttributes.CLOUD_ACCOUNT_ID] = projectId;
     attributes[SemanticResourceAttributes.HOST_ID] = instanceId;
+    attributes[SemanticResourceAttributes.HOST_NAME] = hostname;
     attributes[SemanticResourceAttributes.CLOUD_AVAILABILITY_ZONE] = zoneId;
     attributes[SemanticResourceAttributes.CLOUD_PROVIDER] =
       CloudProviderValues.GCP;
@@ -125,6 +128,15 @@ class GcpDetector implements Detector {
       return '';
     }
   }
+
+  /** Gets hostname from GCP instance metadata. */
+  private async _getHostname(): Promise<string> {
+    try {
+      return await gcpMetadata.instance('hostname');
+    } catch {
+      return '';
+    }
+  }
 }
 
 export const gcpDetector = new GcpDetector();
diff --git a/detectors/node/opentelemetry-resource-detector-gcp/test/detectors/GcpDetector.test.ts b/detectors/node/opentelemetry-resource-detector-gcp/test/detectors/GcpDetector.test.ts
index ee1b59b4e..b101f76b6 100644
--- a/detectors/node/opentelemetry-resource-detector-gcp/test/detectors/GcpDetector.test.ts
+++ b/detectors/node/opentelemetry-resource-detector-gcp/test/detectors/GcpDetector.test.ts
@@ -42,6 +42,7 @@ const INSTANCE_ID_PATH = BASE_PATH + '/instance/id';
 const PROJECT_ID_PATH = BASE_PATH + '/project/project-id';
 const ZONE_PATH = BASE_PATH + '/instance/zone';
 const CLUSTER_NAME_PATH = BASE_PATH + '/instance/attributes/cluster-name';
+const HOSTNAME_PATH = BASE_PATH + '/instance/hostname';
 
 (semver.satisfies(process.version, '>=10') ? describe : describe.skip)(
   'gcpDetector',
@@ -81,7 +82,9 @@ const CLUSTER_NAME_PATH = BASE_PATH + '/instance/attributes/cluster-name';
           .get(ZONE_PATH)
           .reply(200, () => 'project/zone/my-zone', HEADERS)
           .get(CLUSTER_NAME_PATH)
-          .reply(404);
+          .reply(404)
+          .get(HOSTNAME_PATH)
+          .reply(200, () => 'dev.my-project.local', HEADERS);
         const secondaryScope = nock(SECONDARY_HOST_ADDRESS)
           .get(INSTANCE_PATH)
           .reply(200, {}, HEADERS);
@@ -94,7 +97,10 @@ const CLUSTER_NAME_PATH = BASE_PATH + '/instance/attributes/cluster-name';
           accountId: 'my-project-id',
           zone: 'my-zone',
         });
-        assertHostResource(resource, { id: '4520031799277581759' });
+        assertHostResource(resource, {
+          id: '4520031799277581759',
+          name: 'dev.my-project.local',
+        });
       });
 
       it('should populate K8s attributes when KUBERNETES_SERVICE_HOST is set', async () => {
@@ -112,7 +118,9 @@ const CLUSTER_NAME_PATH = BASE_PATH + '/instance/attributes/cluster-name';
           .get(PROJECT_ID_PATH)
           .reply(200, () => 'my-project-id', HEADERS)
           .get(ZONE_PATH)
-          .reply(200, () => 'project/zone/my-zone', HEADERS);
+          .reply(200, () => 'project/zone/my-zone', HEADERS)
+          .get(HOSTNAME_PATH)
+          .reply(200, () => 'dev.my-project.local', HEADERS);
         const secondaryScope = nock(SECONDARY_HOST_ADDRESS)
           .get(INSTANCE_PATH)
           .reply(200, {}, HEADERS);
@@ -144,7 +152,9 @@ const CLUSTER_NAME_PATH = BASE_PATH + '/instance/attributes/cluster-name';
           .get(INSTANCE_ID_PATH)
           .reply(400, undefined, HEADERS)
           .get(CLUSTER_NAME_PATH)
-          .reply(413);
+          .reply(413)
+          .get(HOSTNAME_PATH)
+          .reply(400, undefined, HEADERS);
         const secondaryScope = nock(SECONDARY_HOST_ADDRESS)
           .get(INSTANCE_PATH)
           .reply(200, {}, HEADERS);