opentelemetry-sdk-extension-aws: make eks detector less chatty

Don't print warnings if we are not running inside an eks instance so we can load the
resource detector more generally and avoid warnings in stderr.

Author: xrmx

sdk-extension/opentelemetry-sdk-extension-aws/src/opentelemetry/sdk/extension/aws/resource/eks.py

@@ -14,6 +14,7 @@
 
 import json
 import logging
+import os
 import ssl
 from urllib.request import Request, urlopen
 
@@ -29,6 +30,9 @@
 _CONTAINER_ID_LENGTH = 64
 _GET_METHOD = "GET"
 
+_TOKEN_PATH = "/var/run/secrets/kubernetes.io/serviceaccount/token"
+_CERT_PATH = "/var/run/secrets/kubernetes.io/serviceaccount/ca.crt"
+
 
 def _aws_http_request(method, path, cred_value):
     with urlopen(
@@ -39,18 +43,15 @@ def _aws_http_request(method, path, cred_value):
         ),
         timeout=5,
         context=ssl.create_default_context(
-            cafile="/var/run/secrets/kubernetes.io/serviceaccount/ca.crt"
+            cafile=_CERT_PATH,
         ),
     ) as response:
         return response.read().decode("utf-8")
 
 
 def _get_k8s_cred_value():
     try:
-        with open(
-            "/var/run/secrets/kubernetes.io/serviceaccount/token",
-            encoding="utf8",
-        ) as token_file:
+        with open(_TOKEN_PATH, encoding="utf8") as token_file:
             return "Bearer " + token_file.read()
     # pylint: disable=broad-except
     except Exception as exception:
@@ -97,6 +98,10 @@ def _get_container_id():
     return container_id
 
 
+def _is_k8s() -> bool:
+    return os.path.exists(_TOKEN_PATH) and os.path.exists(_CERT_PATH)
+
+
 class AwsEksResourceDetector(ResourceDetector):
     """Detects attribute values only available when the app is running on AWS
     Elastic Kubernetes Service (EKS) and returns them in a Resource.
@@ -106,6 +111,10 @@ class AwsEksResourceDetector(ResourceDetector):
 
     def detect(self) -> "Resource":
         try:
+            # if we are not running on eks exit early without warnings
+            if not _is_k8s():
+                return Resource.get_empty()
+
             cred_value = _get_k8s_cred_value()
 
             if not _is_eks(cred_value):

sdk-extension/opentelemetry-sdk-extension-aws/tests/resource/test_eks.py

@@ -42,6 +42,10 @@ class AwsEksResourceDetectorTest(unittest.TestCase):
         "opentelemetry.sdk.extension.aws.resource.eks._is_eks",
         return_value=True,
     )
+    @patch(
+        "opentelemetry.sdk.extension.aws.resource.eks._is_k8s",
+        return_value=True,
+    )
     @patch(
         "opentelemetry.sdk.extension.aws.resource.eks._get_cluster_info",
         return_value=f"""{{
@@ -88,6 +92,7 @@ def test_simple_create(
         self,
         mock_open_function,
         mock_get_cluster_info,
+        mock_is_k8s,
         mock_is_eks,
         mock_get_k8_cred_value,
     ):
@@ -104,8 +109,32 @@ def test_simple_create(
         "opentelemetry.sdk.extension.aws.resource.eks._is_eks",
         return_value=False,
     )
+    @patch(
+        "opentelemetry.sdk.extension.aws.resource.eks._is_k8s",
+        return_value=True,
+    )
     def test_if_no_eks_env_var_and_should_raise(
-        self, mock_is_eks, mock_get_k8_cred_value
+        self, mock_is_k8s, mock_is_eks, mock_get_k8_cred_value
     ):
         with self.assertRaises(RuntimeError):
             AwsEksResourceDetector(raise_on_error=True).detect()
+
+    @patch(
+        "opentelemetry.sdk.extension.aws.resource.eks._get_k8s_cred_value",
+        return_value="MOCK_TOKEN",
+    )
+    @patch(
+        "opentelemetry.sdk.extension.aws.resource.eks._is_eks",
+        return_value=False,
+    )
+    @patch(
+        "opentelemetry.sdk.extension.aws.resource.eks._is_k8s",
+        return_value=False,
+    )
+    def test_if_no_eks_paths_should_not_raise(
+        self, mock_is_k8s, mock_is_eks, mock_get_k8_cred_value
+    ):
+        try:
+            AwsEksResourceDetector(raise_on_error=True).detect()
+        except RuntimeError:
+            self.fail("Should not raise")