e2e: allow to run regualar vertical scale tests in OpenStack

If `OPENSTACK_CONTROLPLANE_FLAVOR_ALTERNATE` is found in the environment
variables, we'll use that flavor when running the control plane
verticale scale tests. Otherwise, roll back on the tags.

test/e2e/framework/framework.go

@@ -21,6 +21,7 @@ import (
 	"encoding/json"
 	"errors"
 	"fmt"
+	"os"
 	"regexp"
 	"strconv"
 
@@ -56,6 +57,9 @@ var (
 	// This means that even though the format is correct, we haven't implemented the logic to increase
 	// this instance size.
 	errInstanceTypeNotSupported = errors.New("instance type is not supported")
+
+	// errMissingInstanceSize is returned when the instance size is missing.
+	errMissingInstanceSize = errors.New("instance size is missing")
 )
 
 // Framework is an interface for getting clients and information
@@ -236,6 +240,8 @@ func (f *framework) IncreaseProviderSpecInstanceSize(rawProviderSpec *runtime.Ra
 		return increaseGCPInstanceSize(rawProviderSpec, providerConfig)
 	case configv1.NutanixPlatformType:
 		return increaseNutanixInstanceSize(rawProviderSpec, providerConfig)
+	case configv1.OpenStackPlatformType:
+		return increaseOpenStackInstanceSize(rawProviderSpec, providerConfig)
 	default:
 		return fmt.Errorf("%w: %s", errUnsupportedPlatform, f.platform)
 	}
@@ -683,6 +689,23 @@ func increaseNutanixInstanceSize(rawProviderSpec *runtime.RawExtension, provider
 	return nil
 }
 
+// increase OpenStackInstanceSize increases the instance size of the instance on the providerSpec for an OpenStack providerSpec.
+func increaseOpenStackInstanceSize(rawProviderSpec *runtime.RawExtension, providerConfig providerconfig.ProviderConfig) error {
+	cfg := providerConfig.OpenStack().Config()
+
+	if os.Getenv("OPENSTACK_CONTROLPLANE_FLAVOR_ALTERNATE") == "" {
+		return fmt.Errorf("OPENSTACK_CONTROLPLANE_FLAVOR_ALTERNATE environment variable not set: %w", errMissingInstanceSize)
+	} else {
+		cfg.Flavor = os.Getenv("OPENSTACK_CONTROLPLANE_FLAVOR_ALTERNATE")
+	}
+
+	if err := setProviderSpecValue(rawProviderSpec, cfg); err != nil {
+		return fmt.Errorf("failed to set provider spec value: %w", err)
+	}
+
+	return nil
+}
+
 // nextGCPVMSize returns the next GCP machine size in the series.
 // The Machine sizes being used are in format <e2|n2|n1>-standard-<number>.
 func nextGCPMachineSize(current string) (string, error) {

test/e2e/helpers/machine.go

@@ -20,6 +20,7 @@ import (
 	"context"
 	"errors"
 	"fmt"
+	"os"
 	"regexp"
 	"sort"
 	"strconv"
@@ -409,8 +410,13 @@ func IncreaseControlPlaneMachineInstanceSize(testFramework framework.Framework,
 
 	switch platformType {
 	case configv1.OpenStackPlatformType:
-		// OpenStack flavors are not predictable, so we just tag the instance with a new tag, which will trigger the redeployment.
-		Expect(testFramework.TagInstanceInProviderSpec(updatedProviderSpec.Value)).To(Succeed(), "provider spec should be updated with a new tag")
+		// OpenStack flavors are not predictable. So if OPENSTACK_CONTROLPLANE_FLAVOR_ALTERNATE is set in the environment, we'll use it
+		// to increase the instance size, otherwise we just tag the instance with a new tag, which will trigger the redeployment.
+		if os.Getenv("OPENSTACK_CONTROLPLANE_FLAVOR_ALTERNATE") == "" {
+			Expect(testFramework.TagInstanceInProviderSpec(updatedProviderSpec.Value)).To(Succeed(), "provider spec should be updated with a new tag")
+		} else {
+			Expect(testFramework.IncreaseProviderSpecInstanceSize(updatedProviderSpec.Value)).To(Succeed(), "provider spec should be updated with bigger instance size")
+		}
 	default:
 		Expect(testFramework.IncreaseProviderSpecInstanceSize(updatedProviderSpec.Value)).To(Succeed(), "provider spec should be updated with bigger instance size")
 	}