v0.13.x: fixes for rendering plugin systemd units (#1674)

* Changed Machine.SystemdUnits to inline rather than needing contents->content.
Fixed issue rendering systemd unit templates.
Fixed issue when RemoteFileSpec contains Template and not content.
Refactored extras.go to clean up repeative code.

* Add tests to prove that systemd units are now rendered.

pkg/api/plugin.go

@@ -227,7 +227,7 @@ type SystemdUnits []SystemdUnit
 type SystemdUnit struct {
 	Name string `yaml:"name,omitempty"`
 	// Contents must be a valid go text template producing a valid systemd unit definition
-	Contents `yaml:"contents,omitempty"`
+	Contents `yaml:",inline"`
 }
 
 // Kubelet represents a set of customizations to kubelets running on the nodes

pkg/model/stack_new.go

@@ -204,7 +204,7 @@ func NewEtcdStack(conf *Config, opts api.StackTemplateOptions, extras clusterext
 			stack.ExtraCfnResources = extraStack.Resources
 			stack.ExtraCfnOutputs = extraStack.Outputs
 
-			extraEtcd, err := extras.Etcd()
+			extraEtcd, err := extras.Etcd(conf)
 			if err != nil {
 				return fmt.Errorf("failed to load etcd node extras from plugins: %v", err)
 			}