Identity: Use typed version of namespace id (#87257)

* Remove different constructors and only use NewNamespaceID

* AdminUser: check typed namespace id

* Identity: Add convinient function to parse valid user id when type is either user or service account

* Annotations: Use typed namespace id instead

pkg/services/auth/identity/namespace.go

@@ -41,7 +41,7 @@ func ParseNamespace(str string) (Namespace, error) {
 	}
 }
 
-var AnonymousNamespaceID = MustNewNamespaceID(NamespaceAnonymous, 0)
+var AnonymousNamespaceID = NewNamespaceID(NamespaceAnonymous, 0)
 
 func ParseNamespaceID(str string) (NamespaceID, error) {
 	var namespaceID NamespaceID
@@ -72,27 +72,7 @@ func MustParseNamespaceID(str string) NamespaceID {
 	return namespaceID
 }
 
-// NewNamespaceID creates a new NamespaceID, will fail for invalid namespace.
-func NewNamespaceID(namespace Namespace, id int64) (NamespaceID, error) {
-	return NamespaceID{
-		id:        strconv.FormatInt(id, 10),
-		namespace: namespace,
-	}, nil
-}
-
-// MustNewNamespaceID creates a new NamespaceID, will panic for invalid namespace.
-// Suitable to use in tests or when we can guarantee that we pass a correct format.
-func MustNewNamespaceID(namespace Namespace, id int64) NamespaceID {
-	namespaceID, err := NewNamespaceID(namespace, id)
-	if err != nil {
-		panic(err)
-	}
-	return namespaceID
-}
-
-// NewNamespaceIDUnchecked creates a new NamespaceID without checking if namespace is valid.
-// It us up to the caller to ensure that namespace is valid.
-func NewNamespaceIDUnchecked(namespace Namespace, id int64) NamespaceID {
+func NewNamespaceID(namespace Namespace, id int64) NamespaceID {
 	return NamespaceID{
 		id:        strconv.FormatInt(id, 10),
 		namespace: namespace,
@@ -117,6 +97,16 @@ func (ni NamespaceID) ID() string {
 	return ni.id
 }
 
+// UserID will try to parse and int64 identifier if namespace is either user or service-account.
+// For all other namespaces '0' will be returned.
+func (ni NamespaceID) UserID() (int64, error) {
+	if ni.IsNamespace(NamespaceUser, NamespaceServiceAccount) {
+		return ni.ParseInt()
+	}
+	return 0, nil
+}
+
+// ParseInt will try to parse the id as an int64 identifier.
 func (ni NamespaceID) ParseInt() (int64, error) {
 	return strconv.ParseInt(ni.id, 10, 64)
 }