✨ Add Spot instances support

api/v1alpha2/awsmachine_conversion.go

@@ -59,6 +59,10 @@ func restoreAWSMachineSpec(restored, dst *infrav1alpha3.AWSMachineSpec) {
 
 	// manual conversion for UncompressedUserData
 	dst.UncompressedUserData = restored.UncompressedUserData
+
+	if restored.SpotMarketOptions != nil {
+		dst.SpotMarketOptions = restored.SpotMarketOptions.DeepCopy()
+	}
 }
 
 // ConvertFrom converts from the Hub version (v1alpha3) to this version.

api/v1alpha3/awsmachine_types.go

@@ -119,6 +119,10 @@ type AWSMachineSpec struct {
 	// CloudInit is used.
 	// +optional
 	CloudInit CloudInit `json:"cloudInit,omitempty"`
+
+	// SpotMarketOptions allows users to configure instances to be run using AWS Spot instances.
+	// +optional
+	SpotMarketOptions *SpotMarketOptions `json:"spotMarketOptions,omitempty"`
 }
 
 // CloudInit defines options related to the bootstrapping systems where

api/v1alpha3/types.go

@@ -626,6 +626,9 @@ type Instance struct {
 
 	// Availability zone of instance
 	AvailabilityZone string `json:"availabilityZone,omitempty"`
+
+	// SpotMarketOptions option for configuring instances to be run using AWS Spot instances.
+	SpotMarketOptions *SpotMarketOptions `json:"spotMarketOptions,omitempty"`
 }
 
 // RootVolume encapsulates the configuration options for the root volume
@@ -653,3 +656,13 @@ type RootVolume struct {
 	// +optional
 	EncryptionKey string `json:"encryptionKey,omitempty"`
 }
+
+// SpotMarketOptions defines the options available to a user when configuring
+// Machines to run on Spot instances.
+// Most users should provide an empty struct.
+type SpotMarketOptions struct {
+	// MaxPrice defines the maximum price the user is willing to pay for Spot VM instances
+	// +optional
+	// +kubebuilder:validation:Type=number
+	MaxPrice *string `json:"maxPrice,omitempty"`
+}

config/crd/bases/infrastructure.cluster.x-k8s.io_awsclusters.yaml

@@ -631,6 +631,13 @@ spec:
                     items:
                       type: string
                     type: array
+                  spotMarketOptions:
+                    description: SpotMarketOptions option for configuring instances to be run using AWS Spot instances.
+                    properties:
+                      maxPrice:
+                        description: MaxPrice defines the maximum price the user is willing to pay for Spot VM instances
+                        type: number
+                    type: object
                   sshKeyName:
                     description: The name of the SSH key pair.
                     type: string

config/crd/bases/infrastructure.cluster.x-k8s.io_awsmachines.yaml

@@ -378,6 +378,13 @@ spec:
                 required:
                 - size
                 type: object
+              spotMarketOptions:
+                description: SpotMarketOptions allows users to configure instances to be run using AWS Spot instances.
+                properties:
+                  maxPrice:
+                    description: MaxPrice defines the maximum price the user is willing to pay for Spot VM instances
+                    type: number
+                type: object
               sshKeyName:
                 description: SSHKeyName is the name of the ssh key to attach to the instance. Valid values are empty string (do not use SSH keys), a valid SSH key name, or omitted (use the default SSH key name)
                 type: string

config/crd/bases/infrastructure.cluster.x-k8s.io_awsmachinetemplates.yaml

@@ -341,6 +341,13 @@ spec:
                         required:
                         - size
                         type: object
+                      spotMarketOptions:
+                        description: SpotMarketOptions allows users to configure instances to be run using AWS Spot instances.
+                        properties:
+                          maxPrice:
+                            description: MaxPrice defines the maximum price the user is willing to pay for Spot VM instances
+                            type: number
+                        type: object
                       sshKeyName:
                         description: SSHKeyName is the name of the ssh key to attach to the instance. Valid values are empty string (do not use SSH keys), a valid SSH key name, or omitted (use the default SSH key name)
                         type: string

pkg/cloud/services/ec2/instances.go

@@ -197,6 +197,8 @@ func (s *Service) CreateInstance(scope *scope.MachineScope, userData []byte) (*i
 		}
 	}
 
+	input.SpotMarketOptions = scope.AWSMachine.Spec.SpotMarketOptions
+
 	s.scope.V(2).Info("Running instance", "machine-role", scope.Role())
 	out, err := s.runInstance(scope.Role(), input)
 	if err != nil {
@@ -449,6 +451,8 @@ func (s *Service) runInstance(role string, i *infrav1.Instance) (*infrav1.Instan
 		input.TagSpecifications = append(input.TagSpecifications, spec)
 	}
 
+	input.InstanceMarketOptions = getInstanceMarketOptionsRequest(i.SpotMarketOptions)
+
 	out, err := s.EC2Client.RunInstances(input)
 	if err != nil {
 		return nil, errors.Wrap(err, "failed to run instance")
@@ -790,3 +794,33 @@ func containsGroup(list []string, strToSearch string) bool {
 	}
 	return false
 }
+
+func getInstanceMarketOptionsRequest(spotMarketOptions *infrav1.SpotMarketOptions) *ec2.InstanceMarketOptionsRequest {
+	if spotMarketOptions == nil {
+		// Instance is not a Spot instance
+		return nil
+	}
+
+	// Set required values for Spot instances
+	spotOptions := &ec2.SpotMarketOptions{}
+
+	// The following two options ensure that:
+	// - If an instance is interrupted, it is terminated rather than hibernating or stopping
+	// - No replacement instance will be created if the instance is interrupted
+	// - If the spot request cannot immediately be fulfilled, it will not be created
+	// This behaviour should satisfy the 1:1 mapping of Machines to Instances as
+	// assumed by the Cluster API.
+	spotOptions.SetInstanceInterruptionBehavior(ec2.InstanceInterruptionBehaviorTerminate)
+	spotOptions.SetSpotInstanceType(ec2.SpotInstanceTypeOneTime)
+
+	maxPrice := spotMarketOptions.MaxPrice
+	if maxPrice != nil && *maxPrice != "" {
+		spotOptions.SetMaxPrice(*maxPrice)
+	}
+
+	instanceMarketOptionsRequest := &ec2.InstanceMarketOptionsRequest{}
+	instanceMarketOptionsRequest.SetMarketType(ec2.MarketTypeSpot)
+	instanceMarketOptionsRequest.SetSpotOptions(spotOptions)
+
+	return instanceMarketOptionsRequest
+}

pkg/cloud/services/ec2/instances_test.go

@@ -17,6 +17,7 @@ limitations under the License.
 package ec2
 
 import (
+	"reflect"
 	"testing"
 
 	"github.com/aws/aws-sdk-go/aws"
@@ -1078,6 +1079,67 @@ func TestCreateInstance(t *testing.T) {
 	}
 }
 
+func TestGetInstanceMarketOptionsRequest(t *testing.T) {
+	testCases := []struct {
+		name              string
+		spotMarketOptions *infrav1.SpotMarketOptions
+		expectedRequest   *ec2.InstanceMarketOptionsRequest
+	}{
+		{
+			name:              "with no Spot options specified",
+			spotMarketOptions: nil,
+			expectedRequest:   nil,
+		},
+		{
+			name:              "with an empty Spot options specified",
+			spotMarketOptions: &infrav1.SpotMarketOptions{},
+			expectedRequest: &ec2.InstanceMarketOptionsRequest{
+				MarketType: aws.String(ec2.MarketTypeSpot),
+				SpotOptions: &ec2.SpotMarketOptions{
+					InstanceInterruptionBehavior: aws.String(ec2.InstanceInterruptionBehaviorTerminate),
+					SpotInstanceType:             aws.String(ec2.SpotInstanceTypeOneTime),
+				},
+			},
+		},
+		{
+			name: "with an empty MaxPrice specified",
+			spotMarketOptions: &infrav1.SpotMarketOptions{
+				MaxPrice: aws.String(""),
+			},
+			expectedRequest: &ec2.InstanceMarketOptionsRequest{
+				MarketType: aws.String(ec2.MarketTypeSpot),
+				SpotOptions: &ec2.SpotMarketOptions{
+					InstanceInterruptionBehavior: aws.String(ec2.InstanceInterruptionBehaviorTerminate),
+					SpotInstanceType:             aws.String(ec2.SpotInstanceTypeOneTime),
+				},
+			},
+		},
+		{
+			name: "with a valid MaxPrice specified",
+			spotMarketOptions: &infrav1.SpotMarketOptions{
+				MaxPrice: aws.String("0.01"),
+			},
+			expectedRequest: &ec2.InstanceMarketOptionsRequest{
+				MarketType: aws.String(ec2.MarketTypeSpot),
+				SpotOptions: &ec2.SpotMarketOptions{
+					InstanceInterruptionBehavior: aws.String(ec2.InstanceInterruptionBehaviorTerminate),
+					SpotInstanceType:             aws.String(ec2.SpotInstanceTypeOneTime),
+					MaxPrice:                     aws.String("0.01"),
+				},
+			},
+		},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			request := getInstanceMarketOptionsRequest(tc.spotMarketOptions)
+			if !reflect.DeepEqual(request, tc.expectedRequest) {
+				t.Errorf("Case: %s. Got: %v, expected: %v", tc.name, request, tc.expectedRequest)
+			}
+		})
+	}
+}
+
 func setupScheme() (*runtime.Scheme, error) {
 	scheme := runtime.NewScheme()
 	if err := clusterv1.AddToScheme(scheme); err != nil {