add new filter for meshmodel GET request

Signed-off-by: Pranav Singh <pranavsingh02@hotmail.com>

models/meshmodel/core/v1alpha1/models.go

@@ -14,6 +14,7 @@ import (
 var modelCreationLock sync.Mutex //Each component/relationship will perform a check and if the model already doesn't exist, it will create a model. This lock will make sure that there are no race conditions.
 type ModelFilter struct {
 	Name        string
+	Registrant string //name of the registrant of the model
 	DisplayName string //If Name is already passed, avoid passing Display name unless greedy=true, else the filter will translate to an AND returning only the models where name and display name match exactly. Ignore, if this behavior is expected.
 	Greedy      bool   //when set to true - instead of an exact match, name will be prefix matched. Also an OR will be performed of name and display_name
 	Version     string

models/meshmodel/registry/registry.go

@@ -292,6 +292,8 @@ func (rm *RegistryManager) GetModels(db *database.Handler, f types.Filter) ([]v1
 	type modelWithCategories struct {
 		v1alpha1.ModelDB
 		v1alpha1.CategoryDB
+		Registry
+		Host
 	}
 
 	countUniqueModels := func(models []modelWithCategories) int {
@@ -307,8 +309,10 @@ func (rm *RegistryManager) GetModels(db *database.Handler, f types.Filter) ([]v1
 
 	var modelWithCategoriess []modelWithCategories
 	finder := db.Model(&v1alpha1.ModelDB{}).
-		Select("model_dbs.*, category_dbs.*").
-		Joins("JOIN category_dbs ON model_dbs.category_id = category_dbs.id")
+		Select("model_dbs.*, category_dbs.*", "registries.*", "hosts.*").
+		Joins("JOIN category_dbs ON model_dbs.category_id = category_dbs.id").
+		Joins("JOIN registries ON registries.entity = model_dbs.id").
+		Joins("JOIN hosts ON hosts.id = registries.registrant_id")
 
 	// total count before pagination
 	var count int64
@@ -336,6 +340,9 @@ func (rm *RegistryManager) GetModels(db *database.Handler, f types.Filter) ([]v1
 		if mf.Category != "" {
 			finder = finder.Where("category_dbs.name = ?", mf.Category)
 		}
+		if mf.Registrant != "" {
+			finder = finder.Where("hosts.hostname = ?", mf.Registrant)
+		}
 		if mf.OrderOn != "" {
 			if mf.Sort == "desc" {
 				finder = finder.Order(clause.OrderByColumn{Column: clause.Column{Name: mf.OrderOn}, Desc: true})