Replace gke_container with k8s_container for stackdriver (census-instrumentation#528)

Replaces the gke_container monitored resource type with the new k8s_container
for stackdriver exporters.

Author: c24t

CHANGELOG.md

@@ -6,6 +6,9 @@
   Use `UnknownMetricFamily` for `SumData` instead of `UntypedMetricFamily`.
   Check if label keys and values match before exporting.
 - Remove min and max from Distribution.
+- Replace stackdriver `gke_container` resources, see the [GKE migration
+  notes](https://cloud.google.com/monitoring/kubernetes-engine/migration#incompatible)
+  for details
 
 ## 0.2.0
 Released 2019-01-18

opencensus/common/monitored_resource/gcp_metadata_config.py

@@ -13,63 +13,32 @@
 # limitations under the License.
 
 from opencensus.common.http_handler import get_request
-import os
 
 _GCP_METADATA_URI = 'http://metadata/computeMetadata/v1/'
 _GCP_METADATA_URI_HEADER = {'Metadata-Flavor': 'Google'}
 
-# GCE common attributes
-# See: https://cloud.google.com/appengine/docs/flexible/python/runtime#
-#      environment_variables
-_GCE_ATTRIBUTES = {
-    # ProjectID is the identifier of the GCP project associated with this
-    # resource, such as "my-project".
-    'project_id': 'project/project-id',
-
-    # instance_id is the numeric VM instance identifier assigned by
-    # Compute Engine.
-    'instance_id': 'instance/id',
-
-    # zone is the Compute Engine zone in which the VM is running.
-    'zone': 'instance/zone'
-}
+# ID of the GCP project associated with this resource, such as "my-project"
+PROJECT_ID_KEY = 'project_id'
 
-_GKE_ATTRIBUTES = {
-    # ProjectID is the identifier of the GCP project associated with this
-    # resource, such as "my-project".
-    'project_id': 'project/project-id',
-
-    # instance_id is the numeric VM instance identifier assigned by
-    # Compute Engine.
-    'instance_id': 'instance/id',
-
-    # zone is the Compute Engine zone in which the VM is running.
-    'zone': 'instance/zone',
-
-    # cluster_name is the name for the cluster the container is running in.
-    'cluster_name': 'instance/attributes/cluster-name'
-}
+# Numeric VM instance identifier assigned by GCE
+INSTANCE_ID_KEY = 'instance_id'
 
-# Following attributes are derived from environment variables. They are
-# configured via yaml file. For details refer to:
-# https://cloud.google.com/kubernetes-engine/docs/tutorials/
-# custom-metrics-autoscaling#exporting_metrics_from_the_application
-_GKE_ENV_ATTRIBUTES = {
-    # ContainerName is the name of the container.
-    'container_name': 'CONTAINER_NAME',
+# The GCE zone in which the VM is running
+ZONE_KEY = 'zone'
 
-    # namespace_id is the identifier for the cluster namespace the container
-    # is running in
-    'namespace_id': 'NAMESPACE',
+# GKE cluster name
+CLUSTER_NAME_KEY = 'instance/attributes/cluster-name'
 
-    # pod_id is the identifier for the pod the container is running in.
-    'pod_id': 'HOSTNAME'
+# GCE common attributes
+# See: https://cloud.google.com/appengine/docs/flexible/python/runtime#environment_variables  # noqa
+_GCE_ATTRIBUTES = {
+    PROJECT_ID_KEY: 'project/project-id',
+    INSTANCE_ID_KEY: 'instance/id',
+    ZONE_KEY: 'instance/zone'
 }
 
-# Kubenertes environment variables
-_KUBERNETES_SERVICE_HOST = 'KUBERNETES_SERVICE_HOST'
 
-gcp_metadata_map = {}
+_GCP_METADATA_MAP = {}
 
 
 class GcpMetadataConfig(object):
@@ -90,23 +59,19 @@ def _initialize_metadata_service(cls):
         if cls.inited:
             return
 
-        instance_id = cls._get_attribute('instance_id')
+        instance_id = cls.get_attribute('instance/id')
 
         if instance_id is not None:
             cls.is_running = True
 
-            gcp_metadata_map['instance_id'] = instance_id
-
-            attributes = _GCE_ATTRIBUTES
-            if _KUBERNETES_SERVICE_HOST in os.environ:
-                attributes = _GKE_ATTRIBUTES
+            _GCP_METADATA_MAP['instance_id'] = instance_id
 
             # fetch attributes from metadata request
-            for attribute_key, attribute_uri in attributes.items():
-                if attribute_key not in gcp_metadata_map:
-                    attribute_value = cls._get_attribute(attribute_key)
-                    if attribute_value is not None:
-                        gcp_metadata_map[attribute_key] = attribute_value
+            for attribute_key, attribute_uri in _GCE_ATTRIBUTES.items():
+                if attribute_key not in _GCP_METADATA_MAP:
+                    attribute_value = cls.get_attribute(attribute_uri)
+                    if attribute_value is not None:  # pragma: NO COVER
+                        _GCP_METADATA_MAP[attribute_key] = attribute_value
 
         cls.inited = True
 
@@ -118,35 +83,19 @@ def is_running_on_gcp(cls):
     def get_gce_metadata(self):
         """for GCP GCE instance"""
         if self.is_running_on_gcp():
-            return gcp_metadata_map
+            return _GCP_METADATA_MAP
 
         return dict()
 
-    def get_gke_metadata(self):
-        """for GCP GKE container."""
-        gke_metadata = {}
-
-        if self.is_running_on_gcp():
-            gke_metadata = gcp_metadata_map
-
-        # fetch attributes from Environment Variables
-        for attribute_key, attribute_env in _GKE_ENV_ATTRIBUTES.items():
-            attribute_value = os.environ.get(attribute_env)
-            if attribute_value is not None:
-                gke_metadata[attribute_key] = attribute_value
-
-        return gke_metadata
-
     @staticmethod
-    def _get_attribute(attribute_key):
+    def get_attribute(attribute_uri):
         """
         Fetch the requested instance metadata entry.
         :param attribute_uri: attribute_uri: attribute name relative to the
         computeMetadata/v1 prefix
         :return:  The value read from the metadata service or None
         """
-        attribute_value = get_request(_GCP_METADATA_URI +
-                                      _GKE_ATTRIBUTES[attribute_key],
+        attribute_value = get_request(_GCP_METADATA_URI + attribute_uri,
                                       _GCP_METADATA_URI_HEADER)
 
         if attribute_value is not None and isinstance(attribute_value, bytes):

opencensus/common/monitored_resource/k8s_utils.py

@@ -0,0 +1,64 @@
+# Copyright 2019, OpenCensus Authors
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import os
+
+from opencensus.common.monitored_resource import gcp_metadata_config
+
+# Env var that signals that we're in a kubernetes container
+_KUBERNETES_SERVICE_HOST = 'KUBERNETES_SERVICE_HOST'
+
+# Name of the cluster the container is running in
+CLUSTER_NAME_KEY = 'k8s.io/cluster/name'
+
+# ID of the instance the container is running on
+NAMESPACE_NAME_KEY = 'k8s.io/namespace/name'
+
+# Container pod ID
+POD_NAME_KEY = 'k8s.io/pod/name'
+
+# Container name
+CONTAINER_NAME_KEY = 'k8s.io/container/name'
+
+# Attributes set from environment variables
+_K8S_ENV_ATTRIBUTES = {
+    CONTAINER_NAME_KEY: 'CONTAINER_NAME',
+    NAMESPACE_NAME_KEY: 'NAMESPACE',
+    POD_NAME_KEY: 'HOSTNAME'
+}
+
+
+def is_k8s_environment():
+    """Whether the environment is a kubernetes container.
+
+    The KUBERNETES_SERVICE_HOST environment variable must be set.
+    """
+    return _KUBERNETES_SERVICE_HOST in os.environ
+
+
+def get_k8s_metadata():
+    """Get kubernetes container metadata, as on GCP GKE."""
+    k8s_metadata = {}
+
+    gcp_cluster = (gcp_metadata_config.GcpMetadataConfig
+                   .get_attribute(gcp_metadata_config.CLUSTER_NAME_KEY))
+    if gcp_cluster is not None:
+        k8s_metadata[CLUSTER_NAME_KEY] = gcp_cluster
+
+    for attribute_key, attribute_env in _K8S_ENV_ATTRIBUTES.items():
+        attribute_value = os.environ.get(attribute_env)
+        if attribute_value is not None:
+            k8s_metadata[attribute_key] = attribute_value
+
+    return k8s_metadata

opencensus/common/monitored_resource/monitored_resource.py

@@ -12,29 +12,17 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-import os
-
 from opencensus.common import resource
 from opencensus.common.monitored_resource import aws_identity_doc_utils
 from opencensus.common.monitored_resource import gcp_metadata_config
+from opencensus.common.monitored_resource import k8s_utils
 
 
 # Supported environments (resource types)
 _GCE_INSTANCE = "gce_instance"
-_GKE_CONTAINER = "gke_container"
+_K8S_CONTAINER = "k8s_container"
 _AWS_EC2_INSTANCE = "aws_ec2_instance"
 
-# Kubenertes environment variables
-_KUBERNETES_SERVICE_HOST = 'KUBERNETES_SERVICE_HOST'
-
-
-def is_gke_environment():
-    """Whether the environment is a GKE container instance.
-
-    The KUBERNETES_SERVICE_HOST environment variable must be set.
-    """
-    return _KUBERNETES_SERVICE_HOST in os.environ
-
 
 def is_gce_environment():
     """Whether the environment is a virtual machine on GCE."""
@@ -52,22 +40,11 @@ def get_instance():
     Returns a `Resource` configured for the current environment, or None if the
     environment is unknown or unsupported.
 
-    Supported environments include:
-
-    1. 'gke_container'
-    - https://cloud.google.com/monitoring/api/resources#tag_gke_container
-    2. 'gce_instance'
-    - https://cloud.google.com/monitoring/api/resources#tag_gce_instance
-    3. 'aws_ec2_instance'
-    - https://cloud.google.com/monitoring/api/resources#tag_aws_ec2_instance
-
     :rtype: :class:`opencensus.common.resource.Resource` or None
     :return: A `Resource` configured for the current environment.
     """
-    if is_gke_environment():
-        return resource.Resource(
-            _GKE_CONTAINER,
-            gcp_metadata_config.GcpMetadataConfig().get_gke_metadata())
+    if k8s_utils.is_k8s_environment():
+        return resource.Resource(_K8S_CONTAINER, k8s_utils.get_k8s_metadata())
     if is_gce_environment():
         return resource.Resource(
             _GCE_INSTANCE,