Update no container name behaviour (#186)

* detect resources even if `container_name` is not set

* update tests

* update detection of whether running on GKE

* update tests

* fix lint

Author: munagekar

opentelemetry-resourcedetector-gcp/src/opentelemetry/resourcedetector/gcp_resource_detector/__init__.py

@@ -61,15 +61,19 @@ def get_gce_resources():
 
 def get_gke_resources():
     """Resource finder for GKE attributes"""
-    # The user must specify the container name via the Downward API
-    container_name = os.getenv("CONTAINER_NAME")
-    if container_name is None:
+
+    if os.getenv("KUBERNETES_SERVICE_HOST") is None:
         return {}
+
     (
         common_attributes,
         all_metadata,
     ) = _get_google_metadata_and_common_attributes()
 
+    container_name = os.getenv("CONTAINER_NAME")
+    if container_name is not None:
+        common_attributes["container.name"] = container_name
+
     # Fallback to reading namespace from a file is the env var is not set
     pod_namespace = os.getenv("NAMESPACE")
     if pod_namespace is None:
@@ -89,7 +93,6 @@ def get_gke_resources():
             "k8s.namespace.name": pod_namespace,
             "k8s.pod.name": os.getenv("POD_NAME", os.getenv("HOSTNAME", "")),
             "host.id": all_metadata["instance"]["id"],
-            "container.name": container_name,
             "gcp.resource_type": "gke_container",
         }
     )

opentelemetry-resourcedetector-gcp/tests/test_gcp_resource_detector.py

@@ -29,6 +29,7 @@
 CONTAINER_NAME = "CONTAINER_NAME"
 HOSTNAME = "HOSTNAME"
 POD_NAME = "POD_NAME"
+KUBERNETES_SERVICE_HOST = "KUBERNETES_SERVICE_HOST"
 
 GCE_RESOURCES_JSON_STRING = {
     "instance": {"id": "instance_id", "zone": "projects/123/zones/zone"},
@@ -85,13 +86,34 @@ class TestGKEResourceFinder(unittest.TestCase):
     def tearDown(self) -> None:
         clear_gke_env_vars()
 
+    # pylint: disable=unused-argument
+    def test_not_running_on_gke(self, getter):
+        pop_environ_key(KUBERNETES_SERVICE_HOST)
+        found_resources = get_gke_resources()
+        self.assertEqual(found_resources, {})
+
     # pylint: disable=unused-argument
     def test_missing_container_name(self, getter):
+        os.environ[KUBERNETES_SERVICE_HOST] = "10.0.0.1"
         pop_environ_key(CONTAINER_NAME)
-        self.assertEqual(get_gke_resources(), {})
+        found_resources = get_gke_resources()
+        self.assertEqual(
+            found_resources,
+            {
+                "cloud.account.id": "project_id",
+                "k8s.cluster.name": "cluster_name",
+                "k8s.namespace.name": "",
+                "host.id": "instance_id",
+                "k8s.pod.name": "",
+                "cloud.zone": "zone",
+                "cloud.provider": "gcp",
+                "gcp.resource_type": "gke_container",
+            },
+        )
 
     # pylint: disable=unused-argument
     def test_environment_empty_strings(self, getter):
+        os.environ[KUBERNETES_SERVICE_HOST] = "10.0.0.1"
         os.environ[CONTAINER_NAME] = ""
         os.environ[NAMESPACE] = ""
         found_resources = get_gke_resources()
@@ -111,6 +133,7 @@ def test_environment_empty_strings(self, getter):
         )
 
     def test_missing_namespace_file(self, getter):
+        os.environ[KUBERNETES_SERVICE_HOST] = "10.0.0.1"
         os.environ[CONTAINER_NAME] = "container_name"
         found_resources = get_gke_resources()
         self.assertEqual(
@@ -129,6 +152,7 @@ def test_missing_namespace_file(self, getter):
         )
 
     def test_finding_gke_resources(self, getter):
+        os.environ[KUBERNETES_SERVICE_HOST] = "10.0.0.1"
         os.environ[NAMESPACE] = "namespace"
         os.environ[CONTAINER_NAME] = "container_name"
         os.environ[HOSTNAME] = "host_name"
@@ -150,6 +174,7 @@ def test_finding_gke_resources(self, getter):
         )
 
     def test_finding_gke_resources_with_pod_name(self, getter):
+        os.environ[KUBERNETES_SERVICE_HOST] = "10.0.0.1"
         os.environ[NAMESPACE] = "namespace"
         os.environ[CONTAINER_NAME] = "container_name"
         os.environ[HOSTNAME] = "host_name"
@@ -182,6 +207,7 @@ def tearDown(self) -> None:
     def test_finding_gce_resources(self, getter):
         # The necessary env variables were not set for GKE resource detection
         # to succeed. We should be falling back to detecting GCE resources
+        pop_environ_key(KUBERNETES_SERVICE_HOST)
         resource_finder = GoogleCloudResourceDetector()
         getter.return_value.json.return_value = GCE_RESOURCES_JSON_STRING
         found_resources = resource_finder.detect()
@@ -219,7 +245,7 @@ def test_finding_gce_resources(self, getter):
     def test_finding_gke_resources(self, getter):
         # The necessary env variables were set for GKE resource detection
         # to succeed. No GCE resource info should be extracted
-
+        os.environ[KUBERNETES_SERVICE_HOST] = "10.0.0.1"
         os.environ[NAMESPACE] = "namespace"
         os.environ[CONTAINER_NAME] = "container_name"
         os.environ[HOSTNAME] = "host_name"