Error handling -> fail fast

source/lib/vagrant-openstack-provider/action/create_server.rb

@@ -19,6 +19,11 @@ def initialize(app, _env)
         def call(env)
           @logger.info 'Start create server action'
 
+          config = env[:machine].provider_config
+
+          fail Errors::MissingBootOption if config.image.nil? && config.volume_boot.nil?
+          fail Errors::ConflictBootOption unless config.image.nil? || config.volume_boot.nil?
+
           nova = env[:openstack_client].nova
 
           options = {
@@ -31,9 +36,6 @@ def call(env)
             availability_zone: env[:machine].provider_config.availability_zone
           }
 
-          fail Errors::MissingBootOption if options[:image].nil? && options[:volume_boot].nil?
-          fail Errors::ConflictBootOption unless options[:image].nil? || options[:volume_boot].nil?
-
           server_id = create_server(env, options)
 
           # Store the ID right away so we can track it

source/spec/vagrant-openstack-provider/action/create_server_spec.rb

@@ -100,6 +100,23 @@
     @action = CreateServer.new(nil, nil)
   end
 
+  describe 'call' do
+    context 'with both image and volume_boot specified' do
+      it 'should raise an error' do
+        config.stub(:image) { 'linux-image' }
+        config.stub(:volume_boot) { 'linux-volume' }
+        expect { @action.call(env) }.to raise_error Errors::ConflictBootOption
+      end
+    end
+    context 'with neither image nor volume_boot specified' do
+      it 'should raise an error' do
+        config.stub(:image) { nil }
+        config.stub(:volume_boot) { nil }
+        expect { @action.call(env) }.to raise_error Errors::MissingBootOption
+      end
+    end
+  end
+
   describe 'create_server' do
     context 'with all options specified' do
       it 'calls nova with all the options' do