Add support for spot instances nodegroups

docs/08-spot-instances.yaml

@@ -0,0 +1,22 @@
+# A simple example of ClusterConfig object:
+---
+apiVersion: eksctl.io/v1alpha5
+kind: ClusterConfig
+
+metadata:
+    name: martina-test-spotinst-mixed-9
+    region: eu-central-1
+
+nodeGroups:
+    - name: ng-6
+      ssh:
+          publicKeyPath: ~/.ssh/id_rsa_tests.pub
+      minSize: 2
+      maxSize: 5
+      mixedInstances:
+        maxPrice: 0.017
+        instanceTypes: ["t3.small", "t3.medium", "t3.small"] # Required because we need more instance types
+        onDemandBaseCapacity: 0
+        percentageAboveBase: 100
+        spotInstancePools: 2
+

examples/01-simple-cluster.yaml

@@ -1,5 +1,5 @@
 # A simple example of ClusterConfig object:
---- 
+---
 apiVersion: eksctl.io/v1alpha5
 kind: ClusterConfig
 

pkg/apis/eksctl.io/v1alpha5/types.go

@@ -378,6 +378,8 @@ type NodeGroup struct {
 	AMIFamily string `json:"amiFamily,omitempty"`
 	// +optional
 	InstanceType string `json:"instanceType,omitempty"`
+	//+optional
+	InstancesDistribution *NodeGroupInstancesDistribution `json:"instancesDistribution,omitempty"`
 	// +optional
 	AvailabilityZones []string `json:"availabilityZones,omitempty"`
 	// +optional
@@ -489,4 +491,18 @@ type (
 		// +optional
 		PublicKeyName *string `json:"publicKeyName,omitempty"`
 	}
+
+	// NodeGroupInstancesDistribution holds the configuration for spot instances
+	NodeGroupInstancesDistribution struct {
+		//+required
+		InstanceTypes []string `json:"instanceTypes,omitEmpty"`
+		// +optional
+		MaxPrice *float64 `json:"maxPrice,omitempty"`
+		//+optional
+		OnDemandBaseCapacity *int `json:"onDemandBaseCapacity,omitEmpty"`
+		//+optional
+		PercentageAboveBase *int `json:"percentageAboveBase,omitEmpty"`
+		//+optional
+		SpotInstancePools *int `json:"spotInstancePools,omitEmpty"`
+	}
 )

pkg/apis/eksctl.io/v1alpha5/validation.go

@@ -146,6 +146,50 @@ func ValidateNodeGroup(i int, ng *NodeGroup) error {
 		}
 	}
 
+	if err := validateInstancesDistribution(ng); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+// TODO What happens with the other instance type. Should we use it as well, ignore it, or fail when both are specified?
+// TODO or should we change it to be an array?
+func validateInstancesDistribution(ng *NodeGroup) error {
+	if ng.InstancesDistribution == nil {
+		return nil
+	}
+
+	if ng.InstanceType != "" && ng.InstanceType != "mixed" {
+		return fmt.Errorf("instanceType should be \"mixed\" or unset when using the mixed instances feature")
+	}
+
+	distribution := ng.InstancesDistribution
+	if distribution.InstanceTypes == nil || len(distribution.InstanceTypes) == 0 {
+		return fmt.Errorf("at least two instance types have to be specified for mixed nodegroups")
+	}
+
+	allInstanceTypes := make(map[string]bool)
+	for _, instanceType := range distribution.InstanceTypes {
+		allInstanceTypes[instanceType] = true
+	}
+
+	if len(allInstanceTypes) < 2 || len(allInstanceTypes) > 20 {
+		return fmt.Errorf("mixed nodegroups should have between 2 and 20 different instance types")
+	}
+
+	if distribution.OnDemandBaseCapacity != nil && *distribution.OnDemandBaseCapacity < 0 {
+		return fmt.Errorf("onDemandBaseCapacity should be 0 or more")
+	}
+
+	if distribution.PercentageAboveBase != nil && (*distribution.PercentageAboveBase < 0 || *distribution.PercentageAboveBase > 100) {
+		return fmt.Errorf("percentageAboveBase should be between 0 and 100")
+	}
+
+	if distribution.SpotInstancePools != nil && (*distribution.SpotInstancePools < 1 || *distribution.SpotInstancePools > 20) {
+		return fmt.Errorf("spotInstancePools should be between 1 and 20")
+	}
+
 	return nil
 }
 

pkg/apis/eksctl.io/v1alpha5/validation_test.go

@@ -46,9 +46,98 @@ var _ = Describe("ConfigFile ssh flags validation", func() {
 		err := validateNodeGroupSSH(nil)
 		Expect(err).ToNot(HaveOccurred())
 	})
+
+	Context("Instances distribution", func() {
+
+		var ng *NodeGroup
+		BeforeEach(func() {
+			ng = &NodeGroup{
+				InstancesDistribution: &NodeGroupInstancesDistribution{
+					InstanceTypes: []string{"t3.medium", "t3.large"},
+				},
+			}
+		})
+
+		It("It doesn't panic when instance distribution is not enabled", func() {
+			ng.InstancesDistribution = nil
+			err := validateInstancesDistribution(ng)
+			Expect(err).ToNot(HaveOccurred())
+		})
+
+		It("It fails when instance distribution is enabled and instanceType is not empty or \"mixed\"", func() {
+			err := validateInstancesDistribution(ng)
+			Expect(err).ToNot(HaveOccurred())
+
+			ng.InstanceType = "t3.small"
+
+			err = validateInstancesDistribution(ng)
+			Expect(err).To(HaveOccurred())
+		})
+
+		It("It fails when the instance distribution doesn't have at least 2 different instance types", func() {
+			ng.InstanceType = "mixed"
+			ng.InstancesDistribution.InstanceTypes = []string{"t3.medium", "t3.medium"}
+
+			err := validateInstancesDistribution(ng)
+			Expect(err).To(HaveOccurred())
+
+			ng.InstanceType = "mixed"
+			ng.InstancesDistribution.InstanceTypes = []string{"t3.medium", "t3.small"}
+
+			err = validateInstancesDistribution(ng)
+			Expect(err).ToNot(HaveOccurred())
+		})
+
+		It("It fails when the onDemandBaseCapacity is not above 0", func() {
+			ng.InstancesDistribution.OnDemandBaseCapacity = newInt(-1)
+
+			err := validateInstancesDistribution(ng)
+			Expect(err).To(HaveOccurred())
+
+			ng.InstancesDistribution.OnDemandBaseCapacity = newInt(1)
+
+			err = validateInstancesDistribution(ng)
+			Expect(err).ToNot(HaveOccurred())
+		})
+
+		It("It fails when the spotInstancePools is not between 1 and 20", func() {
+			ng.InstancesDistribution.SpotInstancePools = newInt(0)
+
+			err := validateInstancesDistribution(ng)
+			Expect(err).To(HaveOccurred())
+
+			ng.InstancesDistribution.SpotInstancePools = newInt(21)
+			err = validateInstancesDistribution(ng)
+			Expect(err).To(HaveOccurred())
+
+			ng.InstancesDistribution.SpotInstancePools = newInt(2)
+			err = validateInstancesDistribution(ng)
+			Expect(err).ToNot(HaveOccurred())
+		})
+
+		It("It fails when the percentageAboveBase is not between 0 and 100", func() {
+			ng.InstancesDistribution.PercentageAboveBase = newInt(-1)
+
+			err := validateInstancesDistribution(ng)
+			Expect(err).To(HaveOccurred())
+
+			ng.InstancesDistribution.PercentageAboveBase = newInt(101)
+			err = validateInstancesDistribution(ng)
+			Expect(err).To(HaveOccurred())
+
+			ng.InstancesDistribution.PercentageAboveBase = newInt(50)
+			err = validateInstancesDistribution(ng)
+			Expect(err).ToNot(HaveOccurred())
+		})
+	})
 })
 
 func checkItDetectsError(SSHConfig *NodeGroupSSH) {
 	err := validateNodeGroupSSH(SSHConfig)
 	Expect(err).To(HaveOccurred())
 }
+
+func newInt(value int) *int {
+	v := value
+	return &v
+}

pkg/apis/eksctl.io/v1alpha5/vpc.go

@@ -155,7 +155,7 @@ func (c *ClusterConfig) HasSufficientPublicSubnets() bool {
 }
 
 var errInsufficientSubnets = fmt.Errorf(
-	"inssuficient number of subnets, at least %dx public and/or %dx private subnets are required",
+	"insufficient number of subnets, at least %dx public and/or %dx private subnets are required",
 	MinRequiredSubnets, MinRequiredSubnets)
 
 // HasSufficientSubnets validates if there is a sufficient number