Use interfaces

pkg/actions.go

@@ -1,22 +1,16 @@
 package actions
 
 import (
+	"crypto/md5"
 	"github.com/zalando-incubator/postgres-operator/pkg/cluster/types"
 	"github.com/zalando-incubator/postgres-operator/pkg/spec"
 	"k8s.io/client-go/pkg/api/v1"
 )
 
-type ActionType int
-
-const (
-	UpdateService ActionType = iota
-	RecreateService
-	CreateService
-	DeleteService
-)
-
 var NoActions []Action = []Action{}
 
+type ActionHash = [16]byte
+
 type SyncSecretsData struct {
 	secrets map[string]*v1.Secret
 }
@@ -31,8 +25,79 @@ type SyncVolumesData struct {
 	volumeSpec spec.Volume
 }
 
-type Action struct {
-	actionType actionType
+type ActionData struct {
 	namespace NamespacedName
-	data       interface{}
+}
+
+type CreateService struct {
+	common  ActionData
+	service ServiceData
+}
+
+type UpdateService struct {
+	common  ActionData
+	service ServiceData
+}
+
+type RecreateService struct {
+	common  ActionData
+	service ServiceData
+}
+
+type DeleteService struct {
+	common  ActionData
+	service ServiceData
+}
+
+type Action interface {
+	process() (bool, error)
+	name() string
+	hash() ActionHash
+}
+
+func (action UpdateService) process() (bool, error) {
+
+}
+
+func (action RecreateService) process() (bool, error) {
+}
+
+func (action CreateService) process() (bool, error) {
+
+}
+
+func (action DeleteService) process() (bool, error) {
+
+}
+
+func (action UpdateService) hash() ActionHash {
+	return md5.Sum([]byte("update" + action.data.name))
+}
+
+func (action RecreateService) hash() ActionHash {
+	return md5.Sum([]byte("recreate" + action.data.name))
+}
+
+func (action CreateService) hash() ActionHash {
+	return md5.Sum([]byte("create" + action.data.name))
+}
+
+func (action DeleteService) hash() ActionHash {
+	return md5.Sum([]byte("delete" + action.data.name))
+}
+
+func (action UpdateService) name() string {
+	return fmt.Sprintf("Update service %s", action.service.name)
+}
+
+func (action RecreateService) name() string {
+	return fmt.Sprintf("Recreate service %s", action.service.name)
+}
+
+func (action CreateService) name() string {
+	return fmt.Sprintf("Create a new service")
+}
+
+func (action DeleteService) name() string {
+	return fmt.Sprintf("Delete service %s", action.service.name)
 }

pkg/cluster/resources.go

@@ -339,14 +339,13 @@ func (c *Cluster) createService(role PostgresRole) ([]Action, error) {
 	c.setProcessName("creating %v service", role)
 
 	serviceSpec := c.generateService(role, &c.Spec)
-	return []Action{
-		Action{
-			CreateService,
-			serviceName.Namespace,
+	return []CreateService{
+		ActionData{
+			namespace: serviceName.Namespace,
+		},
 		ServiceData{
 			spec: serviceSpec,
 		},
-		},
 	}, nil
 }
 
@@ -362,15 +361,15 @@ func (c *Cluster) updateService(role PostgresRole, newService *v1.Service) ([]Ac
 	if newService.Spec.Type != c.Services[role].Spec.Type {
 		// service type has changed, need to replace the service completely.
 		// we cannot use just pach the current service, since it may contain attributes incompatible with the new type.
-		return []Action{
-			Action{
-				RecreateService,
+		return []RecreateService{
+			ActionData{
+				namespace: serviceName.Namespace,
+			},
 			ServiceData{
 				name: serviceName.Name,
 				role: role,
 				spec: newService,
 			},
-			},
 		}, nil
 	}
 
@@ -380,29 +379,27 @@ func (c *Cluster) updateService(role PostgresRole, newService *v1.Service) ([]Ac
 		return NoActions, fmt.Errorf("could not form patch for the service %q: %v", serviceName, err)
 	}
 
-	return []Action{
-		Action{
-			CreateService,
-			serviceName.Namespace,
+	return []CreateService{
+		ActionData{
+			namespace: serviceName.Namespace,
+		},
 		ServiceData{
 			name: serviceName.Name,
 			spec: newService,
 		},
-		},
 	}, nil
 }
 
 func (c *Cluster) deleteService(role PostgresRole) error {
 	service := c.Services[role]
 
-	return []Action{
-		Action{
-			DeleteService,
-			serviceName.Namespace,
+	return []DeleteService{
+		ActionData{
+			namespace: serviceName.Namespace,
+		},
 		ServiceData{
 			name: service.Name,
 		},
-		},
 	}, nil
 }
 

pkg/cluster/sync.go

@@ -14,50 +14,9 @@ import (
 	"github.com/zalando-incubator/postgres-operator/pkg/util/volumes"
 )
 
-var syncChannel chan Action
-
-func (c *Cluster) SyncActions(newSpec *spec.Postgresql) (err error) {
-	syncSecrets = Action{
-		SyncSecrets,
-		SyncSecretsData{
-			c.generateUserSecrets(),
-		},
-	}
-
-	syncServiceMaster = Action{
-		SyncService,
-		SyncServiceData{
-			Master,
-		},
-	}
-
-	syncServiceReplica = Action{
-		SyncService,
-		SyncServiceData{
-			Replica,
-		},
-	}
-
-	syncVolumes = Action{
-		SyncVolumes,
-		SyncVolumesData{
-			c.Spec.Volume,
-		},
-	}
-
-	return []Action{
-		syncSecrets,
-		syncServiceMaster,
-		syncServiceReplica,
-		syncVolumes,
-	}
-}
-
 // Sync syncs the cluster, making sure the actual Kubernetes objects correspond to what is defined in the manifest.
 // Unlike the update, sync does not error out if some objects do not exist and takes care of creating them.
 func (c *Cluster) Sync(newSpec *spec.Postgresql) (err error) {
-	syncChannel = make(chan Action)
-
 	c.mu.Lock()
 	defer c.mu.Unlock()
 
@@ -86,8 +45,13 @@ func (c *Cluster) Sync(newSpec *spec.Postgresql) (err error) {
 	}
 
 	c.logger.Debugf("syncing services")
-	if err = c.syncServices(); err != nil {
-		err = fmt.Errorf("could not sync services: %v", err)
+	if actions, err = c.syncServices(); err != nil {
+		err = fmt.Errorf("could not resolve actions to sync services: %v", err)
+		return
+	}
+
+	if err = c.applyActions(actions); err != nil {
+		err = fmt.Errorf("could not apply actions to sync services: %v", err)
 		return
 	}
 
@@ -150,6 +114,23 @@ func (c *Cluster) syncServices() error {
 	return nil
 }
 
+func (c *Cluster) applyActions(actions []Action) (err error) {
+	uniqueActions = []Actions{}
+	hashMap = map[ActionHash]bool{}
+	for idx, action := range actions {
+		if _, present := uniqueActions[action.hash()]; !present {
+			uniqueActions[action.hash()] = true
+			append(uniqueActions, action)
+		}
+	}
+
+	for action := range uniqueActions {
+		if dontStop, err := action.process(); err != nil && !dontStop {
+			c.logger.Errorf("Can't apply action %s: %v", action.name(), err)
+		}
+	}
+}
+
 func (c *Cluster) syncService(role PostgresRole) ([]Action, error) {
 	c.setProcessName("syncing %s service", role)
 
@@ -170,28 +151,16 @@ func (c *Cluster) syncService(role PostgresRole) ([]Action, error) {
 	} else if !k8sutil.ResourceNotFound(err) {
 		return NoActions, fmt.Errorf("could not get %s service: %v", role, err)
 	}
-	c.Services[role] = nil
-
 	c.logger.Infof("could not find the cluster's %s service", role)
 
-	if svc, err := c.createService(role); err != nil {
-		if k8sutil.ResourceAlreadyExists(err) {
-			c.logger.Infof("%s service %q already exists", role, util.NameFromMeta(svc.ObjectMeta))
-			svc, err := c.KubeClient.Services(c.Namespace).Get(c.serviceName(role), metav1.GetOptions{})
-			if err == nil {
-				c.Services[role] = svc
-			} else {
-				c.logger.Infof("could not fetch existing %s service: %v", role, err)
-			}
-		} else {
-			return fmt.Errorf("could not create missing %s service: %v", role, err)
-		}
-	} else {
-		c.logger.Infof("created missing %s service %q", role, util.NameFromMeta(svc.ObjectMeta))
-		c.Services[role] = svc
-	}
-
-	return nil
+	return []CreateService{
+		ActionData{
+			namespace: serviceName.Namespace,
+		},
+		ServiceData{
+			role: role,
+		},
+	}, nil
 }
 
 func (c *Cluster) syncEndpoint(role PostgresRole) error {

pkg/controller/postgresql.go

@@ -264,12 +264,6 @@ func (c *Controller) processEvent(event spec.ClusterEvent) {
 		}
 
 		c.curWorkerCluster.Store(event.WorkerID, cl)
-		actions := cl.SyncActions(event.NewSpec)
-
-		for i, processor := range c.changeProcessors {
-			processor(changes)
-		}
-
 		if err := cl.Sync(event.NewSpec); err != nil {
 			cl.Error = fmt.Errorf("could not sync cluster: %v", err)
 			lg.Error(cl.Error)