From 4f184e8ce3e646d2465c48265af8ed2c8bc5c394 Mon Sep 17 00:00:00 2001
From: Katrina Verey <kn.verey@gmail.com>
Date: Wed, 20 Jan 2021 15:53:46 -0800
Subject: [PATCH] Add validation hook to template command execution

---
 kyaml/fn/framework/framework.go | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/kyaml/fn/framework/framework.go b/kyaml/fn/framework/framework.go
index 688c7c535..7eefcb24a 100644
--- a/kyaml/fn/framework/framework.go
+++ b/kyaml/fn/framework/framework.go
@@ -392,6 +392,11 @@ type Defaulter interface {
 	Default() error
 }
 
+// Validator is implemented by APIs to have Validate invoked
+type Validator interface {
+	Validate() error
+}
+
 func (tc *TemplateCommand) doPreProcess(rl *ResourceList) error {
 	// do any preprocessing
 	if tc.PreProcess != nil {
@@ -531,6 +536,12 @@ func (tc TemplateCommand) Execute(rl *ResourceList) error {
 		}
 	}
 
+	if v, ok := rl.FunctionConfig.(Validator); ok {
+		if err := v.Validate(); err != nil {
+			return err
+		}
+	}
+
 	if err := tc.doPreProcess(rl); err != nil {
 		return err
 	}