Integrate with scaling UI

pkg/deployment/cluster_informer.go

@@ -0,0 +1,104 @@
+//
+// DISCLAIMER
+//
+// Copyright 2018 ArangoDB GmbH, Cologne, Germany
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+// Copyright holder is ArangoDB GmbH, Cologne, Germany
+//
+// Author Ewout Prangsma
+//
+
+package deployment
+
+import (
+	"context"
+	"time"
+
+	"github.com/arangodb/kube-arangodb/pkg/util/arangod"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+)
+
+// listenForClusterEvents keep listening for changes entered in the UI of the cluster.
+func (d *Deployment) listenForClusterEvents(stopCh <-chan struct{}) {
+	for {
+		delay := time.Second * 2
+
+		// Inspect once
+		ctx := context.Background()
+		if err := d.inspectCluster(ctx); err != nil {
+			d.deps.Log.Debug().Err(err).Msg("Cluster inspection failed")
+		}
+
+		select {
+		case <-time.After(delay):
+			// Continue
+		case <-stopCh:
+			// We're done
+			return
+		}
+	}
+}
+
+// Perform a single inspection of the cluster
+func (d *Deployment) inspectCluster(ctx context.Context) error {
+	log := d.deps.Log
+	c, err := d.clientCache.GetDatabase(ctx)
+	if err != nil {
+		return maskAny(err)
+	}
+	req, err := arangod.GetNumberOfServers(ctx, c.Connection())
+	if err != nil {
+		log.Debug().Err(err).Msg("Failed to get number of servers")
+		return maskAny(err)
+	}
+	if req.Coordinators == nil && req.DBServers == nil {
+		// Nothing to check
+		return nil
+	}
+	coordinatorsChanged := false
+	dbserversChanged := false
+	d.lastNumberOfServers.mutex.Lock()
+	defer d.lastNumberOfServers.mutex.Unlock()
+	desired := d.lastNumberOfServers.NumberOfServers
+	if req.Coordinators != nil && desired.Coordinators != nil && req.GetCoordinators() != desired.GetCoordinators() {
+		// #Coordinator has changed
+		coordinatorsChanged = true
+	}
+	if req.DBServers != nil && desired.DBServers != nil && req.GetDBServers() != desired.GetDBServers() {
+		// #DBServers has changed
+		dbserversChanged = true
+	}
+	if !coordinatorsChanged && !dbserversChanged {
+		// Nothing has changed
+		return nil
+	}
+	// Let's update the spec
+	current, err := d.deps.DatabaseCRCli.DatabaseV1alpha().ArangoDeployments(d.apiObject.Namespace).Get(d.apiObject.Name, metav1.GetOptions{})
+	if err != nil {
+		log.Debug().Err(err).Msg("Failed to get current deployment")
+		return maskAny(err)
+	}
+	if coordinatorsChanged {
+		current.Spec.Coordinators.Count = req.GetCoordinators()
+	}
+	if dbserversChanged {
+		current.Spec.DBServers.Count = req.GetDBServers()
+	}
+	if err := d.updateCRSpec(current.Spec); err != nil {
+		log.Warn().Err(err).Msg("Failed to update current deployment")
+		return maskAny(err)
+	}
+	return nil
+}

pkg/deployment/cluster_updater.go

@@ -0,0 +1,50 @@
+//
+// DISCLAIMER
+//
+// Copyright 2018 ArangoDB GmbH, Cologne, Germany
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+// Copyright holder is ArangoDB GmbH, Cologne, Germany
+//
+// Author Ewout Prangsma
+//
+
+package deployment
+
+import (
+	"context"
+
+	"github.com/arangodb/kube-arangodb/pkg/util/arangod"
+)
+
+// updateClusterServerCount updates the intended number of servers of the cluster.
+func (d *Deployment) updateClusterServerCount(ctx context.Context) error {
+	log := d.deps.Log
+	c, err := d.clientCache.GetDatabase(ctx)
+	if err != nil {
+		return maskAny(err)
+	}
+	spec := d.apiObject.Spec
+	coordinatorCount := spec.Coordinators.Count
+	dbserverCount := spec.DBServers.Count
+	if err := arangod.SetNumberOfServers(ctx, c.Connection(), coordinatorCount, dbserverCount); err != nil {
+		log.Debug().Err(err).Msg("Failed to set number of servers")
+		return maskAny(err)
+	}
+	d.lastNumberOfServers.mutex.Lock()
+	defer d.lastNumberOfServers.mutex.Unlock()
+	d.lastNumberOfServers.Coordinators = &coordinatorCount
+	d.lastNumberOfServers.DBServers = &dbserverCount
+	return nil
+}

pkg/deployment/deployment.go

@@ -26,6 +26,7 @@ import (
 	"context"
 	"fmt"
 	"reflect"
+	"sync"
 	"time"
 
 	"github.com/rs/zerolog"
@@ -37,6 +38,7 @@ import (
 
 	api "github.com/arangodb/kube-arangodb/pkg/apis/deployment/v1alpha"
 	"github.com/arangodb/kube-arangodb/pkg/generated/clientset/versioned"
+	"github.com/arangodb/kube-arangodb/pkg/util/arangod"
 	"github.com/arangodb/kube-arangodb/pkg/util/k8sutil"
 	"github.com/arangodb/kube-arangodb/pkg/util/retry"
 	"github.com/arangodb/kube-arangodb/pkg/util/trigger"
@@ -89,8 +91,12 @@ type Deployment struct {
 
 	eventsCli corev1.EventInterface
 
-	inspectTrigger trigger.Trigger
-	clientCache    *clientCache
+	inspectTrigger      trigger.Trigger
+	clientCache         *clientCache
+	lastNumberOfServers struct {
+		arangod.NumberOfServers
+		mutex sync.Mutex
+	}
 }
 
 // New creates a new Deployment from the given API object.
@@ -111,6 +117,9 @@ func New(config Config, deps Dependencies, apiObject *api.ArangoDeployment) (*De
 
 	go d.run()
 	go d.listenForPodEvents()
+	if apiObject.Spec.Mode == api.DeploymentModeCluster {
+		go d.listenForClusterEvents(d.stopCh)
+	}
 
 	return d, nil
 }
@@ -312,6 +321,14 @@ func (d *Deployment) handleArangoDeploymentUpdatedEvent(event *deploymentEvent)
 		return maskAny(fmt.Errorf("failed to update ArangoDeployment spec: %v", err))
 	}
 
+	// Notify cluster of desired server count
+	if d.apiObject.Spec.Mode == api.DeploymentModeCluster {
+		ctx := context.Background()
+		if err := d.updateClusterServerCount(ctx); err != nil {
+			log.Error().Err(err).Msg("Failed to update desired server count in cluster")
+		}
+	}
+
 	// Trigger inspect
 	d.inspectTrigger.Trigger()
 

pkg/util/arangod/cluster.go

@@ -34,6 +34,22 @@ type NumberOfServers struct {
 	DBServers    *int `json:"numberOfDBServers,omitempty"`
 }
 
+// GetCoordinators returns Coordinators if not nil, otherwise 0.
+func (n NumberOfServers) GetCoordinators() int {
+	if n.Coordinators != nil {
+		return *n.Coordinators
+	}
+	return 0
+}
+
+// GetDBServers returns DBServers if not nil, otherwise 0.
+func (n NumberOfServers) GetDBServers() int {
+	if n.DBServers != nil {
+		return *n.DBServers
+	}
+	return 0
+}
+
 // GetNumberOfServers fetches the number of servers the cluster wants to have.
 func GetNumberOfServers(ctx context.Context, conn driver.Connection) (NumberOfServers, error) {
 	req, err := conn.NewRequest("GET", "_admin/cluster/numberOfServers")