Allow addings zones for AWS infra

controllers/provider-aws/pkg/apis/aws/validation/infrastructure.go

@@ -133,7 +133,27 @@ func ValidateInfrastructureConfig(infra *apisaws.InfrastructureConfig, nodesCIDR
 func ValidateInfrastructureConfigUpdate(oldConfig, newConfig *apisaws.InfrastructureConfig, nodesCIDR, podsCIDR, servicesCIDR *string) field.ErrorList {
 	allErrs := field.ErrorList{}
 
-	allErrs = append(allErrs, apivalidation.ValidateImmutableField(newConfig.Networks, oldConfig.Networks, field.NewPath("networks"))...)
+	allErrs = append(allErrs, apivalidation.ValidateImmutableField(newConfig.Networks.VPC, oldConfig.Networks.VPC, field.NewPath("networks.vpc"))...)
+
+	var (
+		oldZones     = oldConfig.Networks.Zones
+		newZones     = newConfig.Networks.Zones
+		missingZones = sets.NewString()
+	)
+
+	for i, oldZone := range oldZones {
+		missingZones.Insert(oldZone.Name)
+		for j, newZone := range newZones {
+			if newZone.Name == oldZone.Name {
+				missingZones.Delete(newZone.Name)
+				allErrs = append(allErrs, apivalidation.ValidateImmutableField(newConfig.Networks.Zones[j], oldConfig.Networks.Zones[j], field.NewPath("networks.zones").Index(i))...)
+			}
+		}
+	}
+
+	for zone := range missingZones {
+		allErrs = append(allErrs, field.Invalid(field.NewPath("networks.zones"), zone, "zone is missing - removing a zone is not supported"))
+	}
 
 	return allErrs
 }

controllers/provider-aws/pkg/apis/aws/validation/infrastructure_test.go

@@ -36,6 +36,7 @@ var _ = Describe("InfrastructureConfig validation", func() {
 		vpc         = "10.0.0.0/8"
 		invalidCIDR = "invalid-cidr"
 		zone        = "zone1"
+		zone2       = "zone2"
 	)
 
 	BeforeEach(func() {
@@ -62,7 +63,6 @@ var _ = Describe("InfrastructureConfig validation", func() {
 			shoot        *gardencorev1alpha1.Shoot
 			region       = "eu-west"
 			region2      = "us-west"
-			zone2        = "zone2"
 		)
 		Context("zones validation", func() {
 			BeforeEach(func() {
@@ -298,11 +298,28 @@ var _ = Describe("InfrastructureConfig validation", func() {
 	})
 
 	Describe("#ValidateInfrastructureConfigUpdate", func() {
+		var zone2 = apisaws.Zone{
+			Name:     zone2,
+			Internal: "10.250.4.0/24",
+			Public:   "10.250.5.0/24",
+			Workers:  "10.250.6.0/24",
+		}
+
 		It("should return no errors for an unchanged config", func() {
 			Expect(ValidateInfrastructureConfigUpdate(infrastructureConfig, infrastructureConfig, &nodes, &pods, &services)).To(BeEmpty())
 		})
 
-		It("should forbid changing the network section", func() {
+		It("should allow adding a zone", func() {
+
+			newInfrastructureConfig := infrastructureConfig.DeepCopy()
+			newInfrastructureConfig.Networks.Zones = append(newInfrastructureConfig.Networks.Zones, zone2)
+
+			errorList := ValidateInfrastructureConfigUpdate(infrastructureConfig, newInfrastructureConfig, &nodes, &pods, &services)
+
+			Expect(errorList).To(BeEmpty())
+		})
+
+		It("should forbid changing the VPC", func() {
 			newInfrastructureConfig := infrastructureConfig.DeepCopy()
 			newCIDR := "1.2.3.4/5"
 			newInfrastructureConfig.Networks.VPC.CIDR = &newCIDR
@@ -311,7 +328,31 @@ var _ = Describe("InfrastructureConfig validation", func() {
 
 			Expect(errorList).To(ConsistOf(PointTo(MatchFields(IgnoreExtras, Fields{
 				"Type":  Equal(field.ErrorTypeInvalid),
-				"Field": Equal("networks"),
+				"Field": Equal("networks.vpc"),
+			}))))
+		})
+
+		It("should forbid changing the zone information", func() {
+			newInfrastructureConfig := infrastructureConfig.DeepCopy()
+			newInfrastructureConfig.Networks.Zones[0].Internal = "10.250.2.0/24"
+
+			errorList := ValidateInfrastructureConfigUpdate(infrastructureConfig, newInfrastructureConfig, &nodes, &pods, &services)
+
+			Expect(errorList).To(ConsistOf(PointTo(MatchFields(IgnoreExtras, Fields{
+				"Type":  Equal(field.ErrorTypeInvalid),
+				"Field": Equal("networks.zones[0]"),
+			}))))
+		})
+
+		It("should forbid removing a zone", func() {
+			newInfrastructureConfig := infrastructureConfig.DeepCopy()
+			newInfrastructureConfig.Networks.Zones[0] = zone2
+
+			errorList := ValidateInfrastructureConfigUpdate(infrastructureConfig, newInfrastructureConfig, &nodes, &pods, &services)
+
+			Expect(errorList).To(ConsistOf(PointTo(MatchFields(IgnoreExtras, Fields{
+				"Type":  Equal(field.ErrorTypeInvalid),
+				"Field": Equal("networks.zones"),
 			}))))
 		})
 	})