From 3dc37e489c4124d4f05b944924318e6048b75b4d Mon Sep 17 00:00:00 2001
From: Robert Laurin <robert.laurin@shopify.com>
Date: Wed, 13 May 2020 14:42:48 -0400
Subject: [PATCH] Add support for automated resource detection

This adds support for populating a resource with with Telemetry data
as well as Google Cloud Platform environment metata data.

For #230
---
 sdk/lib/opentelemetry/sdk/configurator.rb     |  12 +-
 sdk/lib/opentelemetry/sdk/resources.rb        |   2 +
 .../sdk/resources/auto_detector.rb            |  33 +++++
 .../opentelemetry/sdk/resources/constants.rb  | 122 ++++++++++++++++++
 .../detectors/google_cloud_platform.rb        |  52 ++++++++
 .../sdk/resources/detectors/telemetry.rb      |  25 ++++
 .../opentelemetry/sdk/resources/resource.rb   |   1 +
 sdk/lib/opentelemetry/sdk/trace/tracer.rb     |  12 +-
 .../sdk/trace/tracer_provider.rb              |   6 +-
 sdk/opentelemetry-sdk.gemspec                 |   1 +
 .../sdk/resources/auto_detector_test.rb       |  27 ++++
 .../detectors/google_cloud_platform_test.rb   |  64 +++++++++
 .../sdk/resources/detectors/telemetry_test.rb |  28 ++++
 .../sdk/trace/tracer_provider_test.rb         |   3 +-
 .../opentelemetry/sdk/trace/tracer_test.rb    |  12 +-
 sdk/test/test_helper.rb                       |   9 ++
 16 files changed, 385 insertions(+), 24 deletions(-)
 create mode 100644 sdk/lib/opentelemetry/sdk/resources/auto_detector.rb
 create mode 100644 sdk/lib/opentelemetry/sdk/resources/constants.rb
 create mode 100644 sdk/lib/opentelemetry/sdk/resources/detectors/google_cloud_platform.rb
 create mode 100644 sdk/lib/opentelemetry/sdk/resources/detectors/telemetry.rb
 create mode 100644 sdk/test/opentelemetry/sdk/resources/auto_detector_test.rb
 create mode 100644 sdk/test/opentelemetry/sdk/resources/detectors/google_cloud_platform_test.rb
 create mode 100644 sdk/test/opentelemetry/sdk/resources/detectors/telemetry_test.rb

diff --git a/sdk/lib/opentelemetry/sdk/configurator.rb b/sdk/lib/opentelemetry/sdk/configurator.rb
index 1713e8ae44..daaa9eeab5 100644
--- a/sdk/lib/opentelemetry/sdk/configurator.rb
+++ b/sdk/lib/opentelemetry/sdk/configurator.rb
@@ -16,7 +16,7 @@ class Configurator
       private_constant :USE_MODE_UNSPECIFIED, :USE_MODE_ONE, :USE_MODE_ALL
 
       attr_writer :logger, :http_extractors, :http_injectors, :text_extractors,
-                  :text_injectors
+                  :text_injectors, :resource
 
       def initialize
         @adapter_names = []
@@ -27,7 +27,7 @@ def initialize
         @text_injectors = nil
         @span_processors = []
         @use_mode = USE_MODE_UNSPECIFIED
-        @tracer_provider = Trace::TracerProvider.new
+        @resource = OpenTelemetry::SDK::Resources::Resource.create
       end
 
       def logger
@@ -83,12 +83,16 @@ def configure
         OpenTelemetry.correlations = CorrelationContext::Manager.new
         configure_propagation
         configure_span_processors
-        OpenTelemetry.tracer_provider = @tracer_provider
+        OpenTelemetry.tracer_provider = tracer_provider
         install_instrumentation
       end
 
       private
 
+      def tracer_provider
+        @tracer_provider ||= Trace::TracerProvider.new(@resource)
+      end
+
       def check_use_mode!(mode)
         @use_mode = mode if @use_mode == USE_MODE_UNSPECIFIED
         raise 'Use either `use_all` or `use`, but not both' unless @use_mode == mode
@@ -105,7 +109,7 @@ def install_instrumentation
 
       def configure_span_processors
         processors = @span_processors.empty? ? [default_span_processor] : @span_processors
-        processors.each { |p| @tracer_provider.add_span_processor(p) }
+        processors.each { |p| tracer_provider.add_span_processor(p) }
       end
 
       def default_span_processor
diff --git a/sdk/lib/opentelemetry/sdk/resources.rb b/sdk/lib/opentelemetry/sdk/resources.rb
index 7155df90c6..bea8fe9afc 100644
--- a/sdk/lib/opentelemetry/sdk/resources.rb
+++ b/sdk/lib/opentelemetry/sdk/resources.rb
@@ -13,3 +13,5 @@ module Resources
 end
 
 require 'opentelemetry/sdk/resources/resource'
+require 'opentelemetry/sdk/resources/constants'
+require 'opentelemetry/sdk/resources/auto_detector'
diff --git a/sdk/lib/opentelemetry/sdk/resources/auto_detector.rb b/sdk/lib/opentelemetry/sdk/resources/auto_detector.rb
new file mode 100644
index 0000000000..44838e8fe7
--- /dev/null
+++ b/sdk/lib/opentelemetry/sdk/resources/auto_detector.rb
@@ -0,0 +1,33 @@
+# frozen_string_literal: true
+
+# Copyright 2019 OpenTelemetry Authors
+#
+# SPDX-License-Identifier: Apache-2.0
+
+require 'opentelemetry/sdk/resources/detectors/google_cloud_platform'
+require 'opentelemetry/sdk/resources/detectors/telemetry'
+
+module OpenTelemetry
+  module SDK
+    module Resources
+      module AutoDetector
+        extend self
+
+        DETECTORS = [
+          OpenTelemetry::SDK::Resources::Detectors::GoogleCloudPlatform,
+          OpenTelemetry::SDK::Resources::Detectors::Telemetry,
+        ]
+
+        def detect
+          resources = DETECTORS.map do |detector|
+            detector.detect();
+          end
+
+          resources.reduce(OpenTelemetry::SDK::Resources::Resource.create) do |empty_resource, detected_resource|
+            empty_resource.merge(detected_resource)
+          end
+        end
+      end
+    end
+  end
+end
diff --git a/sdk/lib/opentelemetry/sdk/resources/constants.rb b/sdk/lib/opentelemetry/sdk/resources/constants.rb
new file mode 100644
index 0000000000..74531e900a
--- /dev/null
+++ b/sdk/lib/opentelemetry/sdk/resources/constants.rb
@@ -0,0 +1,122 @@
+# frozen_string_literal: true
+
+# Copyright 2019 OpenTelemetry Authors
+#
+# SPDX-License-Identifier: Apache-2.0
+
+module OpenTelemetry
+  module SDK
+    module Resources
+      # Attributes describing a service instance.
+      SERVICE_RESOURCE = {
+        # Logical name of the service.
+        name: 'service.name',
+
+        # A namespace for `service.name`.
+        namespace: 'service.namespace',
+
+        # The string ID of the service instance.
+        instance_id: 'service.instance.id',
+
+        # The version string of the service API or implementation.
+        version: 'service.version',
+      }
+
+      # Attributes describing the telemetry library.
+      TELEMETRY_SDK_RESOURCE = {
+        # The name of the telemetry library.
+        name: 'telemetry.sdk.name',
+
+        # The language of telemetry library and of the code instrumented with it.
+        language: 'telemetry.sdk.language',
+
+        # The version string of the telemetry library
+        version: 'telemetry.sdk.version',
+      }
+
+      # Attributes defining a compute unit (e.g. Container, Process, Lambda
+      # Function).
+      CONTAINER_RESOURCE = {
+        # The container name.
+        name: 'container.name',
+
+        # The name of the image the container was built on.
+        image_name: 'container.image.name',
+
+        # The container image tag.
+        image_tag: 'container.image.tag',
+      }
+
+      FAAS_RESOURCE = {
+        # The name of the function being executed.
+        name: 'faas.name',
+
+        # The unique name of the function being executed.
+        id: 'faas.id',
+
+        # The version string of the function being executed.
+        version: 'faas.version',
+
+        # The execution environment ID as a string.
+        instance: 'faas.instance',
+      }
+
+      # Attributes defining a deployment service (e.g. Kubernetes).
+      K8S_RESOURCE = {
+        # The name of the cluster that the pod is running in.
+        cluster_name: 'k8s.cluster.name',
+
+        # The name of the namespace that the pod is running in.
+        namespace_name: 'k8s.namespace.name',
+
+        # The name of the pod.
+        pod_name: 'k8s.pod.name',
+
+        # The name of the deployment.
+        deployment_name: 'k8s.deployment.name',
+      }
+
+      # Attributes defining a computing instance (e.g. host).
+      HOST_RESOURCE = {
+        # Hostname of the host. It contains what the hostname command returns on the
+        # host machine.
+        hostname: 'host.hostname',
+
+        # Unique host id. For Cloud this must be the instance_id assigned by the
+        # cloud provider
+        id: 'host.id',
+
+        # Name of the host. It may contain what hostname returns on Unix systems,
+        # the fully qualified, or a name specified by the user.
+        name: 'host.name',
+
+        # Type of host. For Cloud this must be the machine type.
+        type: 'host.type',
+
+        # Name of the VM image or OS install the host was instantiated from.
+        image_name: 'host.image.name',
+
+        # VM image id. For Cloud, this value is from the provider.
+        image_id: 'host.image.id',
+
+        # The version string of the VM image.
+        image_version: 'host.image.version',
+      }
+
+      # Attributes defining a running environment (e.g. Cloud, Data Center).
+      CLOUD_RESOURCE = {
+        # Name of the cloud provider. Example values are aws, azure, gcp.
+        provider: 'cloud.provider',
+
+        # The cloud account id used to identify different entities.
+        account_id: 'cloud.account.id',
+
+        # A specific geographical location where different entities can run.
+        region: 'cloud.region',
+
+        # Zones are a sub set of the region connected through low-latency links.
+        zone: 'cloud.zone',
+      }
+    end
+  end
+end
diff --git a/sdk/lib/opentelemetry/sdk/resources/detectors/google_cloud_platform.rb b/sdk/lib/opentelemetry/sdk/resources/detectors/google_cloud_platform.rb
new file mode 100644
index 0000000000..51c206768c
--- /dev/null
+++ b/sdk/lib/opentelemetry/sdk/resources/detectors/google_cloud_platform.rb
@@ -0,0 +1,52 @@
+# frozen_string_literal: true
+
+# Copyright 2019 OpenTelemetry Authors
+#
+# SPDX-License-Identifier: Apache-2.0
+
+require 'google-cloud-env'
+
+module OpenTelemetry
+  module SDK
+    module Resources
+      module Detectors
+        module GoogleCloudPlatform
+          extend self
+
+          def detect
+            gcp_env = Google::Cloud::Env.new
+            return Resource.create unless gcp_env.compute_engine?
+
+            resource_labels = {}
+            resource_labels[CLOUD_RESOURCE[:provider]] = 'gcp'
+            resource_labels[CLOUD_RESOURCE[:account_id]] = gcp_env.project_id || ''
+            resource_labels[CLOUD_RESOURCE[:region]] = gcp_env.instance_attribute('cluster-location') || ''
+            resource_labels[CLOUD_RESOURCE[:zone]] = gcp_env.instance_zone || ''
+
+            resource_labels[HOST_RESOURCE[:hostname]] = hostname
+            resource_labels[HOST_RESOURCE[:id]] = gcp_env.lookup_metadata('instance', 'id') || ''
+            resource_labels[HOST_RESOURCE[:name]] = gcp_env.lookup_metadata('instance', 'hostname') || ''
+
+            if gcp_env.kubernetes_engine?
+              resource_labels[K8S_RESOURCE[:cluster_name]] = gcp_env.instance_attribute('cluster-name') || ''
+              resource_labels[K8S_RESOURCE[:namespace_name]] = gcp_env.kubernetes_engine_namespace_id || ''
+              resource_labels[K8S_RESOURCE[:pod_name]] = hostname
+
+              resource_labels[CONTAINER_RESOURCE[:name]] = ENV['CONTAINER_NAME'] || ''
+            end
+
+            Resource.create(resource_labels)
+          end
+
+          private
+
+          def hostname
+            ENV['HOSTNAME'] || `hostname`&.strip
+          rescue
+            ''
+          end
+        end
+      end
+    end
+  end
+end
diff --git a/sdk/lib/opentelemetry/sdk/resources/detectors/telemetry.rb b/sdk/lib/opentelemetry/sdk/resources/detectors/telemetry.rb
new file mode 100644
index 0000000000..8ba8f05c3a
--- /dev/null
+++ b/sdk/lib/opentelemetry/sdk/resources/detectors/telemetry.rb
@@ -0,0 +1,25 @@
+# frozen_string_literal: true
+
+# Copyright 2019 OpenTelemetry Authors
+#
+# SPDX-License-Identifier: Apache-2.0
+
+module OpenTelemetry
+  module SDK
+    module Resources
+      module Detectors
+        module Telemetry
+          extend self
+
+          def detect
+            resource_labels = {}
+            resource_labels[TELEMETRY_SDK_RESOURCE[:name]] = 'OpenTelemetry'
+            resource_labels[TELEMETRY_SDK_RESOURCE[:language]] = 'ruby'
+            resource_labels[TELEMETRY_SDK_RESOURCE[:version]] = "semver:#{OpenTelemetry::SDK::VERSION}"
+            Resource.create(resource_labels)
+          end
+        end
+      end
+    end
+  end
+end
diff --git a/sdk/lib/opentelemetry/sdk/resources/resource.rb b/sdk/lib/opentelemetry/sdk/resources/resource.rb
index ebaf32e376..0da7e8fb08 100644
--- a/sdk/lib/opentelemetry/sdk/resources/resource.rb
+++ b/sdk/lib/opentelemetry/sdk/resources/resource.rb
@@ -74,3 +74,4 @@ def merge(other)
     end
   end
 end
+
diff --git a/sdk/lib/opentelemetry/sdk/trace/tracer.rb b/sdk/lib/opentelemetry/sdk/trace/tracer.rb
index 2ec2e34688..99f058f6c0 100644
--- a/sdk/lib/opentelemetry/sdk/trace/tracer.rb
+++ b/sdk/lib/opentelemetry/sdk/trace/tracer.rb
@@ -9,21 +9,17 @@ module SDK
     module Trace
       # {Tracer} is the SDK implementation of {OpenTelemetry::Trace::Tracer}.
       class Tracer < OpenTelemetry::Trace::Tracer
-        attr_reader :name
-        attr_reader :version
+        attr_reader :resource
 
         # @api private
         #
         # Returns a new {Tracer} instance.
         #
-        # @param [String] name Instrumentation package name
-        # @param [String] version Instrumentation package version
+        # @param [Resource] resource Containing name and version arguments supplied to the TracerProvider
         #
         # @return [Tracer]
-        def initialize(name, version)
-          @name = name
-          @version = version
-          @resource = Resources::Resource.create('name' => name, 'version' => version)
+        def initialize(resource)
+          @resource = resource
         end
 
         def start_root_span(name, attributes: nil, links: nil, start_timestamp: nil, kind: nil)
diff --git a/sdk/lib/opentelemetry/sdk/trace/tracer_provider.rb b/sdk/lib/opentelemetry/sdk/trace/tracer_provider.rb
index d7da2f1b9e..05b435d054 100644
--- a/sdk/lib/opentelemetry/sdk/trace/tracer_provider.rb
+++ b/sdk/lib/opentelemetry/sdk/trace/tracer_provider.rb
@@ -20,13 +20,14 @@ class TracerProvider < OpenTelemetry::Trace::TracerProvider
         # Returns a new {TracerProvider} instance.
         #
         # @return [TracerProvider]
-        def initialize
+        def initialize(resource = OpenTelemetry::SDK::Resources::Resource.create)
           @mutex = Mutex.new
           @registry = {}
           @active_span_processor = NoopSpanProcessor.instance
           @active_trace_config = Config::TraceConfig::DEFAULT
           @registered_span_processors = []
           @stopped = false
+          @resource = resource
         end
 
         # Returns a {Tracer} instance.
@@ -38,7 +39,8 @@ def initialize
         def tracer(name = nil, version = nil)
           name ||= ''
           version ||= ''
-          @mutex.synchronize { @registry[Key.new(name, version)] ||= Tracer.new(name, version) }
+          resource = @resource.merge(OpenTelemetry::SDK::Resources::Resource.create({ 'name' => name, 'version' => version }))
+          @mutex.synchronize { @registry[Key.new(name, version)] ||= Tracer.new(resource) }
         end
 
         # Attempts to stop all the activity for this {Tracer}. Calls
diff --git a/sdk/opentelemetry-sdk.gemspec b/sdk/opentelemetry-sdk.gemspec
index 4e2e4a40d3..a84b9981a9 100644
--- a/sdk/opentelemetry-sdk.gemspec
+++ b/sdk/opentelemetry-sdk.gemspec
@@ -26,6 +26,7 @@ Gem::Specification.new do |spec|
   spec.required_ruby_version = '>= 2.5.0'
 
   spec.add_dependency 'opentelemetry-api', '~> 0.4.0'
+  spec.add_dependency 'google-cloud-env'
 
   spec.add_development_dependency 'bundler', '>= 1.17'
   spec.add_development_dependency 'faraday', '~> 0.13'
diff --git a/sdk/test/opentelemetry/sdk/resources/auto_detector_test.rb b/sdk/test/opentelemetry/sdk/resources/auto_detector_test.rb
new file mode 100644
index 0000000000..931df89ff2
--- /dev/null
+++ b/sdk/test/opentelemetry/sdk/resources/auto_detector_test.rb
@@ -0,0 +1,27 @@
+# frozen_string_literal: true
+
+# Copyright 2019 OpenTelemetry Authors
+#
+# SPDX-License-Identifier: Apache-2.0
+
+require 'test_helper'
+
+describe OpenTelemetry::SDK::Resources::AutoDetector do
+  let(:auto_detector) { OpenTelemetry::SDK::Resources::AutoDetector }
+  let(:detected_resource) { auto_detector.detect }
+  let(:detected_resource_labels) { detected_resource.label_enumerator.to_h }
+  let(:expected_resource_labels) do
+    {
+      "telemetry.sdk.name" => "OpenTelemetry",
+      "telemetry.sdk.language" => "ruby",
+      "telemetry.sdk.version" => "semver:0.4.0"
+    }
+  end
+
+  describe '.detect' do
+    it 'returns detected resources' do
+      _(detected_resource).must_be_instance_of(OpenTelemetry::SDK::Resources::Resource)
+      _(detected_resource_labels).must_equal(expected_resource_labels)
+    end
+  end
+end
diff --git a/sdk/test/opentelemetry/sdk/resources/detectors/google_cloud_platform_test.rb b/sdk/test/opentelemetry/sdk/resources/detectors/google_cloud_platform_test.rb
new file mode 100644
index 0000000000..de221046f1
--- /dev/null
+++ b/sdk/test/opentelemetry/sdk/resources/detectors/google_cloud_platform_test.rb
@@ -0,0 +1,64 @@
+# frozen_string_literal: true
+
+# Copyright 2019 OpenTelemetry Authors
+#
+# SPDX-License-Identifier: Apache-2.0
+
+require 'test_helper'
+
+describe OpenTelemetry::SDK::Resources::Detectors::GoogleCloudPlatform do
+  let(:detector) { OpenTelemetry::SDK::Resources::Detectors::GoogleCloudPlatform }
+
+  describe '.detect' do
+    let(:detected_resource) { detector.detect }
+    let(:detected_resource_labels) { detected_resource.label_enumerator.to_h }
+    let(:expected_resource_labels) { {} }
+
+    it 'returns an empty resource' do
+      _(detected_resource).must_be_instance_of(OpenTelemetry::SDK::Resources::Resource)
+      _(detected_resource_labels).must_equal(expected_resource_labels)
+    end
+
+    describe 'when in a gcp environment' do
+      before do
+        mock = MiniTest::Mock.new
+        mock.expect(:compute_engine?, true)
+        mock.expect(:project_id, 'opentelemetry')
+        mock.expect(:instance_attribute, 'us-central1', ['cluster-location'])
+        mock.expect(:instance_zone, 'us-central1-a')
+        mock.expect(:lookup_metadata, 'opentelemetry-test', ['instance', 'id'])
+        mock.expect(:lookup_metadata, 'opentelemetry-test', ['instance', 'hostname'])
+        mock.expect(:instance_attribute, 'opentelemetry-cluster', ['cluster-name'])
+        mock.expect(:kubernetes_engine?, true)
+        mock.expect(:kubernetes_engine_namespace_id, 'default')
+
+        with_env({ 'HOSTNAME' => 'opentelemetry-test' }) do
+          Google::Cloud::Env.stub(:new, mock) { detected_resource }
+        end
+      end
+
+      let(:expected_resource_labels) do
+        {
+          'cloud.provider' => 'gcp',
+          'cloud.account.id' => 'opentelemetry',
+          'cloud.region' => 'us-central1',
+          'cloud.zone' => 'us-central1-a',
+          'host.hostname' => 'opentelemetry-test',
+          'host.id' => 'opentelemetry-test',
+          'host.name' => 'opentelemetry-test',
+          'k8s.cluster.name' => 'opentelemetry-cluster',
+          'k8s.namespace.name' => 'default',
+          'k8s.pod.name' => 'opentelemetry-test',
+          'container.name' => ''
+        }
+      end
+
+      it 'returns a resource with gcp attributes' do
+        _(detected_resource).must_be_instance_of(OpenTelemetry::SDK::Resources::Resource)
+        _(detected_resource_labels).must_equal(expected_resource_labels)
+      end
+    end
+  end
+end
+
+
diff --git a/sdk/test/opentelemetry/sdk/resources/detectors/telemetry_test.rb b/sdk/test/opentelemetry/sdk/resources/detectors/telemetry_test.rb
new file mode 100644
index 0000000000..3a54f8c3ad
--- /dev/null
+++ b/sdk/test/opentelemetry/sdk/resources/detectors/telemetry_test.rb
@@ -0,0 +1,28 @@
+# frozen_string_literal: true
+
+# Copyright 2019 OpenTelemetry Authors
+#
+# SPDX-License-Identifier: Apache-2.0
+
+require 'test_helper'
+
+describe OpenTelemetry::SDK::Resources::Detectors::Telemetry do
+  let(:detector) { OpenTelemetry::SDK::Resources::Detectors::Telemetry }
+
+  describe '.detect' do
+    let(:detected_resource) { detector.detect }
+    let(:detected_resource_labels) { detected_resource.label_enumerator.to_h }
+    let(:expected_resource_labels) do
+      {
+        "telemetry.sdk.name" => "OpenTelemetry",
+        "telemetry.sdk.language" => "ruby",
+        "telemetry.sdk.version" => "semver:0.4.0"
+      }
+    end
+
+    it 'returns a resource with telemetry attributes' do
+      _(detected_resource).must_be_instance_of(OpenTelemetry::SDK::Resources::Resource)
+      _(detected_resource_labels).must_equal(expected_resource_labels)
+    end
+  end
+end
diff --git a/sdk/test/opentelemetry/sdk/trace/tracer_provider_test.rb b/sdk/test/opentelemetry/sdk/trace/tracer_provider_test.rb
index bc5ad920fe..7435c446d3 100644
--- a/sdk/test/opentelemetry/sdk/trace/tracer_provider_test.rb
+++ b/sdk/test/opentelemetry/sdk/trace/tracer_provider_test.rb
@@ -86,8 +86,7 @@
 
     it 'returns a default name-less version-less tracer' do
       tracer = tracer_provider.tracer
-      _(tracer.name).must_equal('')
-      _(tracer.version).must_equal('')
+      _(tracer.resource.label_enumerator.to_h).must_equal({ 'name' => '', 'version' => '' })
     end
 
     it 'returns different tracers for different names' do
diff --git a/sdk/test/opentelemetry/sdk/trace/tracer_test.rb b/sdk/test/opentelemetry/sdk/trace/tracer_test.rb
index a9fc55d502..7e97a6feff 100644
--- a/sdk/test/opentelemetry/sdk/trace/tracer_test.rb
+++ b/sdk/test/opentelemetry/sdk/trace/tracer_test.rb
@@ -18,15 +18,11 @@
     ->(trace_id:, span_id:, parent_context:, links:, name:, kind:, attributes:) { Result.new(decision: Decision::RECORD) } # rubocop:disable Lint/UnusedBlockArgument
   end
 
-  describe '#name' do
-    it 'reflects the name passed in' do
-      _(Tracer.new('component', 'semver:1.0').name).must_equal('component')
-    end
-  end
+  describe '#resource' do
+    let(:resource) { OpenTelemetry::SDK::Resources::Resource.create('a' => 'b') }
 
-  describe '#version' do
-    it 'reflects the version passed in' do
-      _(Tracer.new('component', 'semver:1.0').version).must_equal('semver:1.0')
+    it 'reflects the resource passed in' do
+      _(Tracer.new(resource).resource).must_equal(resource)
     end
   end
 
diff --git a/sdk/test/test_helper.rb b/sdk/test/test_helper.rb
index 7f8aa09ad5..0d1fe14a89 100644
--- a/sdk/test/test_helper.rb
+++ b/sdk/test/test_helper.rb
@@ -12,3 +12,12 @@
 require 'minitest/autorun'
 
 OpenTelemetry.logger = Logger.new('/dev/null')
+
+def with_env(new_env)
+  env_to_reset = ENV.select { |k, _| new_env.key?(k) }
+  keys_to_delete = new_env.keys - ENV.keys
+  new_env.each_pair { |k, v| ENV[k] = v }
+  yield
+  env_to_reset.each_pair { |k, v| ENV[k] = v }
+  keys_to_delete.each { |k| ENV.delete(k) }
+end