Add image validation for opestack machine

Signed-off-by: smoshiur1237 <moshiur.rahman@est.tech>

Author: smoshiur1237

api/v1beta1/types.go

@@ -17,6 +17,7 @@ limitations under the License.
 package v1beta1
 
 import (
+	"k8s.io/apimachinery/pkg/util/validation/field"
 	"k8s.io/utils/ptr"
 
 	"sigs.k8s.io/cluster-api-provider-openstack/pkg/utils/optional"
@@ -75,6 +76,24 @@ func (f *ImageFilter) IsZero() bool {
 	return f.Name == nil && len(f.Tags) == 0
 }
 
+// Validate performs validation on [ImageParam], returning a list of field errors using the provided base path.
+// It is intended to be used in the validation webhooks of resources containing [ImageParam].
+func (i *ImageParam) Validate(base field.Path) field.ErrorList {
+	var errors field.ErrorList
+	// Not possible to validate the image if it is missing
+	if i == nil {
+		errors = append(errors, field.Required(&base, "image is required"))
+		return errors
+	}
+	if i.Filter.Name == nil || i.Filter.Tags == nil {
+		errors = append(errors, field.Required(base.Child("Image filter"), "either name or tags of image are missing"))
+	}
+	if i.ImageRef.Name == "" {
+		errors = append(errors, field.Required(base.Child("ORC mage Regerecne"), "Orc image is missing"))
+	}
+	return errors
+}
+
 type ExternalRouterIPParam struct {
 	// The FixedIP in the corresponding subnet
 	FixedIP string `json:"fixedIP,omitempty"`