Cluster-autoscaler: cloud provider interface implementation for AWS

cluster-autoscaler/cloudprovider/aws/aws_cloud_provider.go

@@ -0,0 +1,234 @@
+/*
+Copyright 2016 The Kubernetes Authors All rights reserved.
+
+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.
+*/
+
+package aws
+
+import (
+	"fmt"
+	"regexp"
+	"strconv"
+	"strings"
+
+	"k8s.io/contrib/cluster-autoscaler/cloudprovider"
+	kube_api "k8s.io/kubernetes/pkg/api"
+)
+
+// AwsCloudProvider implements CloudProvider interface.
+type AwsCloudProvider struct {
+	awsManager *AwsManager
+	asgs       []*Asg
+}
+
+// BuildAwsCloudProvider builds CloudProvider implementation for AWS.
+func BuildAwsCloudProvider(awsManager *AwsManager, specs []string) (*AwsCloudProvider, error) {
+	aws := &AwsCloudProvider{
+		awsManager: awsManager,
+		asgs:       make([]*Asg, 0),
+	}
+	for _, spec := range specs {
+		if err := aws.addNodeGroup(spec); err != nil {
+			return nil, err
+		}
+	}
+	return aws, nil
+}
+
+// addNodeGroup adds node group defined in string spec. Format:
+// minNodes:maxNodes:asgName
+func (aws *AwsCloudProvider) addNodeGroup(spec string) error {
+	asg, err := buildAsg(spec, aws.awsManager)
+	if err != nil {
+		return err
+	}
+	aws.asgs = append(aws.asgs, asg)
+	aws.awsManager.RegisterAsg(asg)
+	return nil
+}
+
+// Name returns name of the cloud provider.
+func (aws *AwsCloudProvider) Name() string {
+	return "aws"
+}
+
+// NodeGroups returns all node groups configured for this cloud provider.
+func (aws *AwsCloudProvider) NodeGroups() []cloudprovider.NodeGroup {
+	result := make([]cloudprovider.NodeGroup, 0, len(aws.asgs))
+	for _, asg := range aws.asgs {
+		result = append(result, asg)
+	}
+	return result
+}
+
+// NodeGroupForNode returns the node group for the given node.
+func (aws *AwsCloudProvider) NodeGroupForNode(node *kube_api.Node) (cloudprovider.NodeGroup, error) {
+	ref, err := AwsRefFromProviderId(node.Spec.ProviderID)
+	if err != nil {
+		return nil, err
+	}
+	asg, err := aws.awsManager.GetAsgForInstance(ref)
+	return asg, err
+}
+
+// AwsRef contains a reference to some entity in AWS/GKE world.
+type AwsRef struct {
+	Name string
+}
+
+// AwsRefFromProviderId creates InstanceConfig object from provider id which
+// must be in format: aws:///zone/name
+func AwsRefFromProviderId(id string) (*AwsRef, error) {
+	validIdRegex := regexp.MustCompile(`^aws\:\/\/\/[-0-9a-z]*\/[-0-9a-z]*$`)
+	if validIdRegex.FindStringSubmatch(id) == nil {
+		return nil, fmt.Errorf("Wrong id: expected format aws:///<zone>/<name>, got %v", id)
+	}
+	splitted := strings.Split(id[7:], "/")
+	return &AwsRef{
+		Name: splitted[1],
+	}, nil
+}
+
+// Asg implements NodeGroup interfrace.
+type Asg struct {
+	AwsRef
+
+	awsManager *AwsManager
+
+	minSize int
+	maxSize int
+}
+
+// MaxSize returns maximum size of the node group.
+func (asg *Asg) MaxSize() int {
+	return asg.maxSize
+}
+
+// MinSize returns minimum size of the node group.
+func (asg *Asg) MinSize() int {
+	return asg.minSize
+}
+
+// TargetSize returns the current TARGET size of the node group. It is possible that the
+// number is different from the number of nodes registered in Kuberentes.
+func (asg *Asg) TargetSize() (int, error) {
+	size, err := asg.awsManager.GetAsgSize(asg)
+	return int(size), err
+}
+
+// IncreaseSize increases Asg size
+func (asg *Asg) IncreaseSize(delta int) error {
+	if delta <= 0 {
+		return fmt.Errorf("size increase must be positive")
+	}
+	size, err := asg.awsManager.GetAsgSize(asg)
+	if err != nil {
+		return err
+	}
+	if int(size)+delta > asg.MaxSize() {
+		return fmt.Errorf("size increase too large - desired:%d max:%d", int(size)+delta, asg.MaxSize())
+	}
+	return asg.awsManager.SetAsgSize(asg, size+int64(delta))
+}
+
+// Belongs returns true if the given node belongs to the NodeGroup.
+func (asg *Asg) Belongs(node *kube_api.Node) (bool, error) {
+	ref, err := AwsRefFromProviderId(node.Spec.ProviderID)
+	if err != nil {
+		return false, err
+	}
+	targetAsg, err := asg.awsManager.GetAsgForInstance(ref)
+	if err != nil {
+		return false, err
+	}
+	if targetAsg == nil {
+		return false, fmt.Errorf("%s doesn't belong to a known asg", node.Name)
+	}
+	if targetAsg.Id() != asg.Id() {
+		return false, nil
+	}
+	return true, nil
+}
+
+// DeleteNodes deletes the nodes from the group.
+func (asg *Asg) DeleteNodes(nodes []*kube_api.Node) error {
+	size, err := asg.awsManager.GetAsgSize(asg)
+	if err != nil {
+		return err
+	}
+	if int(size) <= asg.MinSize() {
+		return fmt.Errorf("min size reached, nodes will not be deleted")
+	}
+	refs := make([]*AwsRef, 0, len(nodes))
+	for _, node := range nodes {
+		belongs, err := asg.Belongs(node)
+		if err != nil {
+			return err
+		}
+		if belongs != true {
+			return fmt.Errorf("%s belongs to a different asg than %s", node.Name, asg.Id())
+		}
+		awsref, err := AwsRefFromProviderId(node.Spec.ProviderID)
+		if err != nil {
+			return err
+		}
+		refs = append(refs, awsref)
+	}
+	return asg.awsManager.DeleteInstances(refs)
+}
+
+// Id returns asg id.
+func (asg *Asg) Id() string {
+	return asg.Name
+}
+
+// Debug returns a debug string for the Asg.
+func (asg *Asg) Debug() string {
+	return fmt.Sprintf("%s (%d:%d)", asg.Id(), asg.MinSize(), asg.MaxSize())
+}
+
+func buildAsg(value string, awsManager *AwsManager) (*Asg, error) {
+	tokens := strings.SplitN(value, ":", 3)
+	if len(tokens) != 3 {
+		return nil, fmt.Errorf("wrong nodes configuration: %s", value)
+	}
+
+	asg := Asg{
+		awsManager: awsManager,
+	}
+	if size, err := strconv.Atoi(tokens[0]); err == nil {
+		if size <= 0 {
+			return nil, fmt.Errorf("min size must be >= 1")
+		}
+		asg.minSize = size
+	} else {
+		return nil, fmt.Errorf("failed to set min size: %s, expected integer", tokens[0])
+	}
+
+	if size, err := strconv.Atoi(tokens[1]); err == nil {
+		if size < asg.minSize {
+			return nil, fmt.Errorf("max size must be greater or equal to min size")
+		}
+		asg.maxSize = size
+	} else {
+		return nil, fmt.Errorf("failed to set max size: %s, expected integer", tokens[1])
+	}
+
+	if tokens[2] == "" {
+		return nil, fmt.Errorf("asg name must not be blank: %s got error: %v", tokens[2])
+	}
+
+	asg.Name = tokens[2]
+	return &asg, nil
+}