feat: 🎸 add node name for k8s (#250)

Author: bestgopher

opentelemetry-resource-detectors/src/k8s.rs

@@ -34,6 +34,12 @@ impl ResourceDetector for K8sResourceDetector {
                             name,
                         )
                     }),
+                    env::var("NODE_NAME").ok().map(|name| {
+                        KeyValue::new(
+                            opentelemetry_semantic_conventions::attribute::K8S_NODE_NAME,
+                            name,
+                        )
+                    }),
                 ]
                 .into_iter()
                 .flatten(),
@@ -49,27 +55,45 @@ mod tests {
 
     #[test]
     fn test_k8s_resource_detector_with_env_vars() {
-        temp_env::with_vars([("HOSTNAME", Some("test-pod"))], || {
-            let resource = K8sResourceDetector.detect();
+        temp_env::with_vars(
+            [
+                ("HOSTNAME", Some("test-pod")),
+                ("NODE_NAME", Some("test-node")),
+            ],
+            || {
+                let resource = K8sResourceDetector.detect();
 
-            assert_eq!(resource.len(), 1);
+                assert_eq!(resource.len(), 2);
 
-            assert_eq!(
-                resource.get(&Key::from_static_str(
-                    opentelemetry_semantic_conventions::attribute::K8S_POD_NAME
-                )),
-                Some(Value::from("test-pod"))
-            )
-        });
+                assert_eq!(
+                    resource.get(&Key::from_static_str(
+                        opentelemetry_semantic_conventions::attribute::K8S_POD_NAME
+                    )),
+                    Some(Value::from("test-pod"))
+                );
+
+                assert_eq!(
+                    resource.get(&Key::from_static_str(
+                        opentelemetry_semantic_conventions::attribute::K8S_NODE_NAME
+                    )),
+                    Some(Value::from("test-node"))
+                )
+            },
+        );
     }
 
     #[test]
     fn test_k8s_resource_detector_with_missing_env_vars() {
         // make sure no env var is accidentally set
-        temp_env::with_vars_unset(["HOSTNAME"], || {
+        temp_env::with_vars_unset(["HOSTNAME", "NODE_NAME"], || {
             let resource = K8sResourceDetector.detect();
 
             assert_eq!(resource.len(), 0);
+            assert!(resource
+                .get(&Key::from_static_str(
+                    opentelemetry_semantic_conventions::attribute::K8S_NODE_NAME
+                ))
+                .is_none())
         });
     }
 }