Fix flaky prometheus_updater_spec by cleaning up PROCESS_TYPE env var (#4868)

Author: joyvuu-dave

spec/unit/lib/cloud_controller/runner_spec.rb

@@ -11,6 +11,22 @@ module VCAP::CloudController
 
     let(:argv) { [] }
 
+    # Runner#initialize calls set_process_type_env which sets
+    # ENV['PROCESS_TYPE'] to 'main'. Normally PROCESS_TYPE is unset in the
+    # test environment. This leak is harmless today ('main' maps to
+    # API_PUMA_MAIN, the same default), but it is still pollution that should
+    # be cleaned up.
+    around do |example|
+      original_process_type = ENV.fetch('PROCESS_TYPE', nil)
+      example.run
+    ensure
+      if original_process_type.nil?
+        ENV.delete('PROCESS_TYPE')
+      else
+        ENV['PROCESS_TYPE'] = original_process_type
+      end
+    end
+
     before do
       allow(Steno).to receive(:init)
       allow(CloudController::DependencyLocator.instance).to receive(:routing_api_client).and_return(routing_api_client)

spec/unit/lib/cloud_controller/runners/puma_runner_spec.rb

@@ -33,6 +33,23 @@ module VCAP::CloudController
       PumaRunner.new(test_config, app, logger, periodic_updater, request_logs)
     end
 
+    # The before_worker_boot callback calls set_process_type_env which sets
+    # ENV['PROCESS_TYPE'] to 'puma_worker'. Normally PROCESS_TYPE is unset in
+    # the test environment, allowing ExecutionContext.from_process_type_env to
+    # fall back to API_PUMA_MAIN via the CC_TEST=true check. This leak is
+    # harmless today (API_PUMA_WORKER registers all metrics just like
+    # API_PUMA_MAIN), but it is still pollution that should be cleaned up.
+    around do |example|
+      original_process_type = ENV.fetch('PROCESS_TYPE', nil)
+      example.run
+    ensure
+      if original_process_type.nil?
+        ENV.delete('PROCESS_TYPE')
+      else
+        ENV['PROCESS_TYPE'] = original_process_type
+      end
+    end
+
     before do
       allow(logger).to receive(:info)
       allow(CloudController::DependencyLocator).to receive(:instance).and_return(dependency_locator)

spec/unit/lib/sequel/extensions/connection_metrics_spec.rb

@@ -10,6 +10,26 @@
   let(:prometheus_updater) { spy(VCAP::CloudController::Metrics::PrometheusUpdater) }
   let(:thread) { double('Thread') }
 
+  # Tests in this file call set_process_type_env which sets ENV['PROCESS_TYPE']
+  # to 'cc-worker' or 'puma_worker'. Normally PROCESS_TYPE is unset in the
+  # test environment, allowing ExecutionContext.from_process_type_env to fall
+  # back to API_PUMA_MAIN via the CC_TEST=true check. The 'cc-worker' value
+  # is the actual cause of flaky prometheus_updater_spec failures: it maps to
+  # CC_WORKER, which only registers a subset of metrics, so registry.get()
+  # returns nil for unregistered metrics. The 'puma_worker' value happens to
+  # be harmless today (API_PUMA_WORKER registers all metrics), but it is
+  # still pollution that should be cleaned up.
+  around do |example|
+    original_process_type = ENV.fetch('PROCESS_TYPE', nil)
+    example.run
+  ensure
+    if original_process_type.nil?
+      ENV.delete('PROCESS_TYPE')
+    else
+      ENV['PROCESS_TYPE'] = original_process_type
+    end
+  end
+
   after do
     db.disconnect
   end