Add test support for airgapped environments

Use airgapped network for runner

This will allow the runner to run in an airgapped network
that is shared with the main GitLab container

Add an Instance scenario for Airgapped

Add an airgap check of an initial wget to prove that DNS is
functioning, ping commands to show initial connectivity and
then airgap, and a netcat check of port 80

qa/qa.rb

@@ -137,6 +137,7 @@ module QA
       module Instance
         autoload :All, 'qa/scenario/test/instance/all'
         autoload :Smoke, 'qa/scenario/test/instance/smoke'
+        autoload :Airgapped, 'qa/scenario/test/instance/airgapped'
       end
 
       module Integration

qa/qa/scenario/test/instance/airgapped.rb

+# frozen_string_literal: true
+
+module QA
+  module Scenario
+    module Test
+      module Instance
+        class Airgapped < Template
+          include Bootable
+          include SharedAttributes
+          def perform(address, *rspec_options)
+            Runtime::Scenario.define(:runner_network, 'airgapped')
+
+            super
+          end
+        end
+      end
+    end
+  end
+end

qa/qa/service/docker_run/base.rb

@@ -8,6 +8,7 @@ module QA
 
         def initialize
           @network = Runtime::Scenario.attributes[:network] || 'test'
+          @runner_network = Runtime::Scenario.attributes[:runner_network] || @network
         end
 
         def network
@@ -18,6 +19,14 @@ module QA
           @network
         end
 
+        def runner_network
+          shell "docker network inspect #{@runner_network}"
+        rescue CommandError
+          network
+        else
+          @runner_network
+        end
+
         def pull
           shell "docker pull #{@image}"
         end

qa/qa/service/docker_run/gitlab_runner.rb

 # frozen_string_literal: true
 
+require 'resolv'
 require 'securerandom'
 
 module QA
@@ -38,11 +39,16 @@ module QA
         def register!
           shell <<~CMD.tr("\n", ' ')
             docker run -d --rm --entrypoint=/bin/sh
-            --network #{network} --name #{@name}
+            --network #{runner_network} --name #{@name}
             #{'-v /var/run/docker.sock:/var/run/docker.sock' if @executor == :docker}
             --privileged
             #{@image} -c "#{register_command}"
           CMD
+
+          # Prove airgappedness
+          if runner_network == 'airgapped'
+            shell("docker exec #{@name} sh -c '#{prove_airgap}'")
+          end
         end
 
         def tags=(tags)
@@ -85,6 +91,17 @@ module QA
             gitlab-runner run
           CMD
         end
+
+        # Ping CloudFlare DNS, should fail
+        # Ping Registry, should fail to resolve
+        def prove_airgap
+          gitlab_ip = Resolv.getaddress 'registry.gitlab.com'
+          <<~CMD
+            echo "Checking airgapped connectivity..."
+            nc -zv -w 10 #{gitlab_ip} 80 && (echo "Airgapped network faulty. Connectivity netcat check failed." && exit 1) || (echo "Connectivity netcat check passed." && exit 0)
+            wget --retry-connrefused --waitretry=1 --read-timeout=15 --timeout=10 -t 2 http://registry.gitlab.com > /dev/null 2>&1 && (echo "Airgapped network faulty. Connectivity wget check failed." && exit 1) || (echo "Airgapped network confirmed. Connectivity wget check passed." && exit 0)
+          CMD
+        end
       end
     end
   end

qa/qa/service/docker_run/jenkins.rb

@@ -16,7 +16,9 @@ module QA
         end
 
         def host_name
-          return 'localhost' unless QA::Runtime::Env.running_in_ci?
+          if !QA::Runtime::Env.running_in_ci? && !runner_network.equal?('airgapped')
+            'localhost'
+          end
 
           super
         end
@@ -33,7 +35,9 @@ module QA
             #{@image}
           CMD
 
-          command.gsub!("--network #{network} ", '') unless QA::Runtime::Env.running_in_ci?
+          if !QA::Runtime::Env.running_in_ci? && !runner_network.equal?('airgapped')
+            command.gsub!("--network #{network} ", '')
+          end
 
           shell command
         end

qa/spec/scenario/test/instance/airgapped_spec.rb

+# frozen_string_literal: true
+
+describe QA::Scenario::Test::Instance::Airgapped do
+  describe '#perform' do
+    it_behaves_like 'a QA scenario class' do
+    end
+  end
+end