Add typed errors, add errors_total metric

cluster-autoscaler/core/autoscaler.go

@@ -22,6 +22,7 @@ import (
 	"github.com/golang/glog"
 	"k8s.io/autoscaler/cluster-autoscaler/config/dynamic"
 	"k8s.io/autoscaler/cluster-autoscaler/simulator"
+	"k8s.io/autoscaler/cluster-autoscaler/utils/errors"
 	kube_util "k8s.io/autoscaler/cluster-autoscaler/utils/kubernetes"
 	kube_record "k8s.io/client-go/tools/record"
 	kube_client "k8s.io/kubernetes/pkg/client/clientset_generated/clientset"
@@ -37,7 +38,7 @@ type AutoscalerOptions struct {
 // The configuration can be injected at the creation of an autoscaler
 type Autoscaler interface {
 	// RunOnce represents an iteration in the control-loop of CA
-	RunOnce(currentTime time.Time)
+	RunOnce(currentTime time.Time) *errors.AutoscalerError
 	// CleanUp represents a clean-up required before the first invocation of RunOnce
 	CleanUp()
 	// ExitCleanUp is a clean-up performed just before process termination.

cluster-autoscaler/core/dynamic_autoscaler.go

@@ -24,6 +24,7 @@ import (
 	"k8s.io/autoscaler/cluster-autoscaler/config/dynamic"
 	"k8s.io/autoscaler/cluster-autoscaler/metrics"
 	"k8s.io/autoscaler/cluster-autoscaler/simulator"
+	"k8s.io/autoscaler/cluster-autoscaler/utils/errors"
 	kube_util "k8s.io/autoscaler/cluster-autoscaler/utils/kubernetes"
 	kube_record "k8s.io/client-go/tools/record"
 	kube_client "k8s.io/kubernetes/pkg/client/clientset_generated/clientset"
@@ -56,14 +57,14 @@ func (a *DynamicAutoscaler) ExitCleanUp() {
 }
 
 // RunOnce represents a single iteration of a dynamic autoscaler inside the CA's control-loop
-func (a *DynamicAutoscaler) RunOnce(currentTime time.Time) {
+func (a *DynamicAutoscaler) RunOnce(currentTime time.Time) *errors.AutoscalerError {
 	reconfigureStart := time.Now()
 	metrics.UpdateLastTime("reconfigure", reconfigureStart)
 	if err := a.Reconfigure(); err != nil {
 		glog.Errorf("Failed to reconfigure : %v", err)
 	}
 	metrics.UpdateDuration("reconfigure", reconfigureStart)
-	a.autoscaler.RunOnce(currentTime)
+	return a.autoscaler.RunOnce(currentTime)
 }
 
 // Reconfigure this dynamic autoscaler if the configmap is updated

cluster-autoscaler/core/dynamic_autoscaler_test.go

@@ -19,6 +19,7 @@ package core
 import (
 	"github.com/stretchr/testify/mock"
 	"k8s.io/autoscaler/cluster-autoscaler/config/dynamic"
+	"k8s.io/autoscaler/cluster-autoscaler/utils/errors"
 	"testing"
 	"time"
 )
@@ -27,8 +28,9 @@ type AutoscalerMock struct {
 	mock.Mock
 }
 
-func (m *AutoscalerMock) RunOnce(currentTime time.Time) {
+func (m *AutoscalerMock) RunOnce(currentTime time.Time) *errors.AutoscalerError {
 	m.Called(currentTime)
+	return nil
 }
 
 func (m *AutoscalerMock) CleanUp() {

cluster-autoscaler/core/polling_autoscaler.go

@@ -21,6 +21,7 @@ import (
 
 	"github.com/golang/glog"
 	"k8s.io/autoscaler/cluster-autoscaler/metrics"
+	"k8s.io/autoscaler/cluster-autoscaler/utils/errors"
 )
 
 // PollingAutoscaler is a variant of autoscaler which polls the source-of-truth every time RunOnce is invoked
@@ -48,14 +49,14 @@ func (a *PollingAutoscaler) ExitCleanUp() {
 }
 
 // RunOnce represents a single iteration of a polling autoscaler inside the CA's control-loop
-func (a *PollingAutoscaler) RunOnce(currentTime time.Time) {
+func (a *PollingAutoscaler) RunOnce(currentTime time.Time) *errors.AutoscalerError {
 	reconfigureStart := time.Now()
 	metrics.UpdateLastTime("poll", reconfigureStart)
 	if err := a.Poll(); err != nil {
 		glog.Errorf("Failed to poll : %v", err)
 	}
 	metrics.UpdateDuration("poll", reconfigureStart)
-	a.autoscaler.RunOnce(currentTime)
+	return a.autoscaler.RunOnce(currentTime)
 }
 
 // Poll latest data from cloud provider to recreate this autoscaler

cluster-autoscaler/core/scale_down.go

@@ -27,9 +27,10 @@ import (
 	"k8s.io/autoscaler/cluster-autoscaler/metrics"
 	"k8s.io/autoscaler/cluster-autoscaler/simulator"
 	"k8s.io/autoscaler/cluster-autoscaler/utils/deletetaint"
+	"k8s.io/autoscaler/cluster-autoscaler/utils/errors"
 	kube_util "k8s.io/autoscaler/cluster-autoscaler/utils/kubernetes"
 
-	"k8s.io/apimachinery/pkg/api/errors"
+	kube_errors "k8s.io/apimachinery/pkg/api/errors"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	kube_record "k8s.io/client-go/tools/record"
 	apiv1 "k8s.io/kubernetes/pkg/api/v1"
@@ -113,7 +114,7 @@ func (sd *ScaleDown) UpdateUnneededNodes(
 	nodes []*apiv1.Node,
 	pods []*apiv1.Pod,
 	timestamp time.Time,
-	pdbs []*policyv1.PodDisruptionBudget) error {
+	pdbs []*policyv1.PodDisruptionBudget) *errors.AutoscalerError {
 
 	currentlyUnneededNodes := make([]*apiv1.Node, 0)
 	nodeNameToNodeInfo := schedulercache.CreateNodeNameToInfoMap(pods, nodes)
@@ -152,18 +153,18 @@ func (sd *ScaleDown) UpdateUnneededNodes(
 	}
 
 	// Phase2 - check which nodes can be probably removed using fast drain.
-	nodesToRemove, newHints, err := simulator.FindNodesToRemove(currentlyUnneededNodes, nodes, pods,
+	nodesToRemove, newHints, simulatorErr := simulator.FindNodesToRemove(currentlyUnneededNodes, nodes, pods,
 		nil, sd.context.PredicateChecker,
 		len(currentlyUnneededNodes), true, sd.podLocationHints, sd.usageTracker, timestamp, pdbs)
-	if err != nil {
-		glog.Errorf("Error while simulating node drains: %v", err)
+	if simulatorErr != nil {
+		glog.Errorf("Error while simulating node drains: %v", simulatorErr)
 
 		sd.unneededNodesList = make([]*apiv1.Node, 0)
 		sd.unneededNodes = make(map[string]time.Time)
 		sd.nodeUtilizationMap = make(map[string]float64)
 		sd.context.ClusterStateRegistry.UpdateScaleDownCandidates(sd.unneededNodesList, timestamp)
 
-		return fmt.Errorf("error while simulating node drains: %v", err)
+		return simulatorErr.AddPrefix("error while simulating node drains: ")
 	}
 
 	// Update the timestamp map.
@@ -190,7 +191,7 @@ func (sd *ScaleDown) UpdateUnneededNodes(
 
 // TryToScaleDown tries to scale down the cluster. It returns ScaleDownResult indicating if any node was
 // removed and error if such occured.
-func (sd *ScaleDown) TryToScaleDown(nodes []*apiv1.Node, pods []*apiv1.Pod, pdbs []*policyv1.PodDisruptionBudget) (ScaleDownResult, error) {
+func (sd *ScaleDown) TryToScaleDown(nodes []*apiv1.Node, pods []*apiv1.Pod, pdbs []*policyv1.PodDisruptionBudget) (ScaleDownResult, *errors.AutoscalerError) {
 
 	now := time.Now()
 	candidates := make([]*apiv1.Node, 0)
@@ -248,7 +249,7 @@ func (sd *ScaleDown) TryToScaleDown(nodes []*apiv1.Node, pods []*apiv1.Pod, pdbs
 	// to recreate on other nodes.
 	emptyNodes := getEmptyNodes(candidates, pods, sd.context.MaxEmptyBulkDelete, sd.context.CloudProvider)
 	if len(emptyNodes) > 0 {
-		confirmation := make(chan error, len(emptyNodes))
+		confirmation := make(chan *errors.AutoscalerError, len(emptyNodes))
 		for _, node := range emptyNodes {
 			glog.V(0).Infof("Scale-down: removing empty node %s", node.Name)
 			sd.context.LogRecorder.Eventf(apiv1.EventTypeNormal, "ScaleDownEmpty", "Scale-down: removing empty node %s", node.Name)
@@ -267,14 +268,14 @@ func (sd *ScaleDown) TryToScaleDown(nodes []*apiv1.Node, pods []*apiv1.Pod, pdbs
 				confirmation <- deleteErr
 			}(node)
 		}
-		var finalError error
+		var finalError *errors.AutoscalerError
 
 		startTime := time.Now()
 		for range emptyNodes {
 			timeElapsed := time.Now().Sub(startTime)
 			timeLeft := MaxCloudProviderNodeDeletionTime - timeElapsed
 			if timeLeft < 0 {
-				finalError = fmt.Errorf("Failed to delete nodes in time")
+				finalError = errors.NewAutoscalerError(errors.TransientError, "Failed to delete nodes in time")
 				break
 			}
 			select {
@@ -284,13 +285,13 @@ func (sd *ScaleDown) TryToScaleDown(nodes []*apiv1.Node, pods []*apiv1.Pod, pdbs
 					finalError = err
 				}
 			case <-time.After(timeLeft):
-				finalError = fmt.Errorf("Failed to delete nodes in time")
+				finalError = errors.NewAutoscalerError(errors.TransientError, "Failed to delete nodes in time")
 			}
 		}
 		if finalError == nil {
 			return ScaleDownNodeDeleted, nil
 		}
-		return ScaleDownError, fmt.Errorf("failed to delete at least one empty node: %v", finalError)
+		return ScaleDownError, finalError.AddPrefix("failed to delete at least one empty node: ")
 	}
 
 	// We look for only 1 node so new hints may be incomplete.
@@ -299,7 +300,7 @@ func (sd *ScaleDown) TryToScaleDown(nodes []*apiv1.Node, pods []*apiv1.Pod, pdbs
 		sd.podLocationHints, sd.usageTracker, time.Now(), pdbs)
 
 	if err != nil {
-		return ScaleDownError, fmt.Errorf("Find node to remove failed: %v", err)
+		return ScaleDownError, err.AddPrefix("Find node to remove failed: ")
 	}
 	if len(nodesToRemove) == 0 {
 		glog.V(1).Infof("No node to remove")
@@ -320,7 +321,7 @@ func (sd *ScaleDown) TryToScaleDown(nodes []*apiv1.Node, pods []*apiv1.Pod, pdbs
 	simulator.RemoveNodeFromTracker(sd.usageTracker, toRemove.Node.Name, sd.unneededNodes)
 	err = deleteNode(sd.context, toRemove.Node, toRemove.PodsToReschedule)
 	if err != nil {
-		return ScaleDownError, fmt.Errorf("Failed to delete %s: %v", toRemove.Node.Name, err)
+		return ScaleDownError, err.AddPrefix("Failed to delete %s: ", toRemove.Node.Name)
 	}
 	if readinessMap[toRemove.Node.Name] {
 		metrics.RegisterScaleDown(1, metrics.Underutilized)
@@ -373,7 +374,7 @@ func getEmptyNodes(candidates []*apiv1.Node, pods []*apiv1.Pod, maxEmptyBulkDele
 	return result[:limit]
 }
 
-func deleteNode(context *AutoscalingContext, node *apiv1.Node, pods []*apiv1.Pod) error {
+func deleteNode(context *AutoscalingContext, node *apiv1.Node, pods []*apiv1.Pod) *errors.AutoscalerError {
 	if err := drainNode(node, pods, context.ClientSet, context.Recorder, context.MaxGratefulTerminationSec,
 		MaxPodEvictionTime, EvictionRetryTime); err != nil {
 		return err
@@ -410,13 +411,13 @@ func evictPod(podToEvict *apiv1.Pod, client kube_client.Interface, recorder kube
 // Performs drain logic on the node. Marks the node as unschedulable and later removes all pods, giving
 // them up to MaxGracefulTerminationTime to finish.
 func drainNode(node *apiv1.Node, pods []*apiv1.Pod, client kube_client.Interface, recorder kube_record.EventRecorder,
-	maxGratefulTerminationSec int, maxPodEvictionTime time.Duration, waitBetweenRetries time.Duration) error {
+	maxGratefulTerminationSec int, maxPodEvictionTime time.Duration, waitBetweenRetries time.Duration) *errors.AutoscalerError {
 
 	drainSuccessful := false
 	toEvict := len(pods)
 	if err := deletetaint.MarkToBeDeleted(node, client); err != nil {
 		recorder.Eventf(node, apiv1.EventTypeWarning, "ScaleDownFailed", "failed to mark the node as toBeDeleted/unschedulable: %v", err)
-		return err
+		return errors.ToAutoscalerError(errors.ApiCallError, err)
 	}
 
 	// If we fail to evict all the pods from the node we want to remove delete taint
@@ -448,11 +449,13 @@ func drainNode(node *apiv1.Node, pods []*apiv1.Pod, client kube_client.Interface
 				metrics.RegisterEvictions(1)
 			}
 		case <-time.After(retryUntil.Sub(time.Now()) + 5*time.Second):
-			return fmt.Errorf("Failed to drain node %s/%s: timeout when waiting for creating evictions", node.Namespace, node.Name)
+			return errors.NewAutoscalerError(
+				errors.ApiCallError, "Failed to drain node %s/%s: timeout when waiting for creating evictions", node.Namespace, node.Name)
 		}
 	}
 	if len(evictionErrs) != 0 {
-		return fmt.Errorf("Failed to drain node %s/%s, due to following errors: %v", node.Namespace, node.Name, evictionErrs)
+		return errors.NewAutoscalerError(
+			errors.ApiCallError, "Failed to drain node %s/%s, due to following errors: %v", node.Namespace, node.Name, evictionErrs)
 	}
 
 	// Evictions created successfully, wait maxGratefulTerminationSec + PodEvictionHeadroom to see if pods really disappeared.
@@ -466,7 +469,7 @@ func drainNode(node *apiv1.Node, pods []*apiv1.Pod, client kube_client.Interface
 				allGone = false
 				break
 			}
-			if !errors.IsNotFound(err) {
+			if !kube_errors.IsNotFound(err) {
 				glog.Errorf("Failed to check pod %s/%s: %v", pod.Namespace, pod.Name, err)
 				allGone = false
 			}
@@ -478,7 +481,8 @@ func drainNode(node *apiv1.Node, pods []*apiv1.Pod, client kube_client.Interface
 			return nil
 		}
 	}
-	return fmt.Errorf("Failed to drain node %s/%s: pods remaining after timeout", node.Namespace, node.Name)
+	return errors.NewAutoscalerError(
+		errors.TransientError, "Failed to drain node %s/%s: pods remaining after timeout", node.Namespace, node.Name)
 }
 
 // cleanToBeDeleted cleans ToBeDeleted taints.
@@ -499,16 +503,17 @@ func cleanToBeDeleted(nodes []*apiv1.Node, client kube_client.Interface, recorde
 // Removes the given node from cloud provider. No extra pre-deletion actions are executed on
 // the Kubernetes side.
 func deleteNodeFromCloudProvider(node *apiv1.Node, cloudProvider cloudprovider.CloudProvider,
-	recorder kube_record.EventRecorder, registry *clusterstate.ClusterStateRegistry) error {
+	recorder kube_record.EventRecorder, registry *clusterstate.ClusterStateRegistry) *errors.AutoscalerError {
 	nodeGroup, err := cloudProvider.NodeGroupForNode(node)
 	if err != nil {
-		return fmt.Errorf("failed to node group for %s: %v", node.Name, err)
+		return errors.NewAutoscalerError(
+			errors.CloudProviderError, "failed to find node group for %s: %v", node.Name, err)
 	}
 	if nodeGroup == nil || reflect.ValueOf(nodeGroup).IsNil() {
-		return fmt.Errorf("picked node that doesn't belong to a node group: %s", node.Name)
+		return errors.NewAutoscalerError(errors.InternalError, "picked node that doesn't belong to a node group: %s", node.Name)
 	}
 	if err = nodeGroup.DeleteNodes([]*apiv1.Node{node}); err != nil {
-		return fmt.Errorf("failed to delete %s: %v", node.Name, err)
+		return errors.NewAutoscalerError(errors.CloudProviderError, "failed to delete %s: %v", node.Name, err)
 	}
 	recorder.Eventf(node, apiv1.EventTypeNormal, "ScaleDown", "node removed by cluster autoscaler")
 	registry.RegisterScaleDown(&clusterstate.ScaleDownRequest{

cluster-autoscaler/core/scale_up.go

@@ -17,13 +17,13 @@ limitations under the License.
 package core
 
 import (
-	"fmt"
 	"time"
 
 	"k8s.io/autoscaler/cluster-autoscaler/clusterstate"
 	"k8s.io/autoscaler/cluster-autoscaler/estimator"
 	"k8s.io/autoscaler/cluster-autoscaler/expander"
 	"k8s.io/autoscaler/cluster-autoscaler/metrics"
+	"k8s.io/autoscaler/cluster-autoscaler/utils/errors"
 	apiv1 "k8s.io/kubernetes/pkg/api/v1"
 	extensionsv1 "k8s.io/kubernetes/pkg/apis/extensions/v1beta1"
 	"k8s.io/kubernetes/plugin/pkg/scheduler/schedulercache"
@@ -35,7 +35,7 @@ import (
 // false if it didn't and error if an error occured. Assumes that all nodes in the cluster are
 // ready and in sync with instance groups.
 func ScaleUp(context *AutoscalingContext, unschedulablePods []*apiv1.Pod, nodes []*apiv1.Node,
-	daemonSets []*extensionsv1.DaemonSet) (bool, error) {
+	daemonSets []*extensionsv1.DaemonSet) (bool, *errors.AutoscalerError) {
 	// From now on we only care about unschedulable pods that were marked after the newest
 	// node became available for the scheduler.
 	if len(unschedulablePods) == 0 {
@@ -49,14 +49,17 @@ func ScaleUp(context *AutoscalingContext, unschedulablePods []*apiv1.Pod, nodes
 	nodeInfos, err := GetNodeInfosForGroups(nodes, context.CloudProvider, context.ClientSet,
 		daemonSets, context.PredicateChecker)
 	if err != nil {
-		return false, fmt.Errorf("failed to build node infos for node groups: %v", err)
+		return false, err.AddPrefix("failed to build node infos for node groups: ")
 	}
 
 	upcomingNodes := make([]*schedulercache.NodeInfo, 0)
 	for nodeGroup, numberOfNodes := range context.ClusterStateRegistry.GetUpcomingNodes() {
 		nodeTemplate, found := nodeInfos[nodeGroup]
 		if !found {
-			return false, fmt.Errorf("failed to find template node for node group %s", nodeGroup)
+			return false, errors.NewAutoscalerError(
+				errors.InternalError,
+				"failed to find template node for node group %s",
+				nodeGroup)
 		}
 		for i := 0; i < numberOfNodes; i++ {
 			upcomingNodes = append(upcomingNodes, nodeTemplate)
@@ -153,7 +156,9 @@ func ScaleUp(context *AutoscalingContext, unschedulablePods []*apiv1.Pod, nodes
 
 		currentSize, err := bestOption.NodeGroup.TargetSize()
 		if err != nil {
-			return false, fmt.Errorf("failed to get node group size: %v", err)
+			return false, errors.NewAutoscalerError(
+				errors.CloudProviderError,
+				"failed to get node group size: %v", err)
 		}
 		newSize := currentSize + bestOption.NodeCount
 		if newSize >= bestOption.NodeGroup.MaxSize() {
@@ -165,14 +170,17 @@ func ScaleUp(context *AutoscalingContext, unschedulablePods []*apiv1.Pod, nodes
 			glog.V(1).Infof("Capping size to max cluster total size (%d)", context.MaxNodesTotal)
 			newSize = context.MaxNodesTotal - len(nodes) + currentSize
 			if newSize < currentSize {
-				return false, fmt.Errorf("max node total count already reached")
+				return false, errors.NewAutoscalerError(
+					errors.TransientError,
+					"max node total count already reached")
 			}
 		}
 
 		glog.V(0).Infof("Scale-up: setting group %s size to %d", bestOption.NodeGroup.Id(), newSize)
 		increase := newSize - currentSize
 		if err := bestOption.NodeGroup.IncreaseSize(increase); err != nil {
-			return false, fmt.Errorf("failed to increase node group size: %v", err)
+			return false, errors.NewAutoscalerError(
+				errors.CloudProviderError, "failed to increase node group size: %v", err)
 		}
 		context.ClusterStateRegistry.RegisterScaleUp(
 			&clusterstate.ScaleUpRequest{