exit application if domain setting is used

spec/fixtures/vmpooler_domain.yaml

@@ -0,0 +1,45 @@
+---
+:providers:
+  :dummy:
+
+:redis:
+  server: 'localhost'
+
+:auth:
+   provider: dummy
+
+:tagfilter:
+  url: '(.*)\/'
+
+:config:
+  site_name: 'vmpooler'
+  # Need to change this on Windows
+  logfile: '/var/log/vmpooler.log'
+  task_limit: 10
+  timeout: 15
+  vm_checktime: 1
+  vm_lifetime: 12
+  vm_lifetime_auth: 24
+  allowed_tags:
+    - 'created_by'
+    - 'project'
+  domain: 'example.com'
+  prefix: 'poolvm-'
+
+# Uncomment the lines below to suppress metrics to STDOUT
+# :statsd:
+#   server: 'localhost'
+#   prefix: 'vmpooler'
+#   port: 8125
+
+:pools:
+  - name: 'pool01'
+    size: 5
+    provider: dummy
+    dns_plugin: 'example'
+    ready_ttl: 5
+  - name: 'pool02'
+    size: 5
+    provider: dummy
+    dns_plugin: 'example'
+    ready_ttl: 5

spec/unit/vmpooler_spec.rb

@@ -70,5 +70,30 @@ describe 'Vmpooler' do
         expect(Vmpooler.config[:config]).not_to be_nil #merge does not deleted existing keys
       end
     end
+
+    context 'when domain' do
+      context 'is set as a variable' do
+        before(:each) do
+          ENV['VMPOOLER_CONFIG_FILE'] = config_file
+          ENV['DOMAIN'] = 'example.com'
+        end
+
+        it 'should exit' do
+          expect { Vmpooler.config }.to raise_error(SystemExit)
+        end
+      end
+
+      context 'is set in a config file' do
+        let(:config_file) { File.join(fixtures_dir, 'vmpooler_domain.yaml') }
+
+        before(:each) do
+          ENV['VMPOOLER_CONFIG_FILE'] = config_file
+        end
+
+        it 'should exit' do
+          expect { Vmpooler.config }.to raise_error(SystemExit)
+        end
+      end
+    end
   end
 end