def get_instance():
"""Get a resource based on the application environment.
Returns a `Resource` configured for the current environment, or None if the
environment is unknown or unsupported.
:rtype: :class:`opencensus.common.resource.Resource` or None
:return: A `Resource` configured for the current environment.
"""
resources = []
env_resource = resource.get_from_env()
if env_resource is not None:
resources.append(env_resource)
if k8s_utils.is_k8s_environment():
resources.append(resource.Resource(
_K8S_CONTAINER, k8s_utils.get_k8s_metadata()))
if is_gce_environment():
resources.append(resource.Resource(
_GCE_INSTANCE,
gcp_metadata_config.GcpMetadataConfig().get_gce_metadata()))
elif is_aws_environment():
resources.append(resource.Resource(
_AWS_EC2_INSTANCE,
(aws_identity_doc_utils.AwsIdentityDocumentUtils()
.get_aws_metadata())))
if not resources:
return None
return resource.merge_resources(resources)
def test_merge_resource(self):
with self.assertRaises(ValueError):
resource_module.merge_resources(None)
with self.assertRaises(ValueError):
resource_module.merge_resources([])
r1 = Resource(None, {'lk1': 'lv11'})
r2 = Resource('t2', {'lk1': 'lv12', 'lk2': 'lv22'})
r3 = Resource('t3', {'lk2': 'lv23', 'lk3': 'lv33'})
merged = resource_module.merge_resources([r1, r2, r3])
self.assertEqual(merged.type, 't2')
self.assertDictEqual(merged.labels, {
'lk1': 'lv11',
'lk2': 'lv22',
'lk3': 'lv33'
})
def test_merge_resource_no_type(self):
r1 = Resource(None)
r2 = Resource(None)
merged = resource_module.merge_resources([r1, r2])
self.assertEqual(merged.type, None)