Merge branch 'sh-fix-capybara-fd-leak' into 'master'

Fix file descriptor leak with Capybara

See merge request gitlab-org/gitlab!30422

ee/spec/features/clusters/cluster_health_dashboard_spec.rb

@@ -2,7 +2,7 @@
 
 require 'spec_helper'
 
-describe 'Cluster Health board', :js, :use_clean_rails_memory_store_caching, :sidekiq_inline do
+describe 'Cluster Health board', :js, :kubeclient, :use_clean_rails_memory_store_caching, :sidekiq_inline do
   include KubernetesHelpers
   include PrometheusHelpers
 

ee/spec/features/markdown/metrics_spec.rb

@@ -2,7 +2,7 @@
 
 require 'spec_helper'
 
-describe 'Metrics rendering', :js, :use_clean_rails_memory_store_caching, :sidekiq_inline do
+describe 'Metrics rendering', :js, :kubeclient, :use_clean_rails_memory_store_caching, :sidekiq_inline do
   include PrometheusHelpers
   include KubernetesHelpers
   include MetricsDashboardUrlHelpers

spec/features/projects/environments_pod_logs_spec.rb

@@ -2,7 +2,7 @@
 
 require 'spec_helper'
 
-describe 'Environment > Pod Logs', :js do
+describe 'Environment > Pod Logs', :js, :kubeclient do
   include KubernetesHelpers
 
   let(:pod_names) { %w(kube-pod) }

spec/features/projects/serverless/functions_spec.rb

@@ -40,7 +40,7 @@ describe 'Functions', :js do
     it_behaves_like "it's missing knative installation"
   end
 
-  context 'when the user has a cluster and knative installed and visits the serverless page' do
+  context 'when the user has a cluster and knative installed and visits the serverless page', :kubeclient do
     let(:cluster) { create(:cluster, :project, :provided_by_gcp, projects: [project]) }
     let(:service) { cluster.platform_kubernetes }
     let(:environment) { create(:environment, project: project) }

spec/support/capybara.rb

@@ -95,12 +95,23 @@ RSpec.configure do |config|
   config.include CapybaraHelpers, type: :feature
 
   config.before(:context, :js) do
+    # This prevents Selenium from creating thousands of connections while waiting for
+    # an element to appear
+    webmock_enable_with_http_connect_on_start!
+
     next if $capybara_server_already_started
 
     TestEnv.eager_load_driver_server
     $capybara_server_already_started = true
   end
 
+  config.after(:context, :js) do
+    # WebMock doesn't stub connections, so we need to restore the original behavior
+    # to prevent many specs from failing:
+    # https://github.com/bblimke/webmock/blob/master/README.md#connecting-on-nethttpstart
+    webmock_enable!
+  end
+
   config.before(:example, :js) do
     session = Capybara.current_session
 

spec/support/kubeclient.rb

+# frozen_string_literal: true
+
+RSpec.configure do |config|
+  # Feature specs call webmock_enable_with_http_connect_on_start!  by
+  # default. This is needed to prevent Kubeclient from connecting to a
+  # host before the request is stubbed.
+  config.before(:each, :kubeclient) do
+    webmock_enable!
+  end
+end

spec/support/webmock.rb

@@ -15,4 +15,20 @@ def webmock_allowed_hosts
   end.compact.uniq
 end
 
-WebMock.disable_net_connect!(allow_localhost: true, allow: webmock_allowed_hosts)
+# This prevents Selenium/WebMock from spawning thousands of connections
+# while waiting for an element to appear via Capybara's find:
+# https://github.com/teamcapybara/capybara/issues/2322#issuecomment-619321520
+def webmock_enable_with_http_connect_on_start!
+  webmock_enable!(net_http_connect_on_start: true)
+end
+
+def webmock_enable!(options = {})
+  WebMock.disable_net_connect!(
+    {
+      allow_localhost: true,
+      allow: webmock_allowed_hosts
+    }.merge(options)
+  )
+end
+
+webmock_enable!