diff --git a/kyaml/openapi/openapi.go b/kyaml/openapi/openapi.go
index 5f1ace8e5..a349388fa 100644
--- a/kyaml/openapi/openapi.go
+++ b/kyaml/openapi/openapi.go
@@ -6,6 +6,7 @@ package openapi
 import (
 	"encoding/json"
 	"fmt"
+	"io/ioutil"
 	"sync"
 
 	"github.com/go-openapi/spec"
@@ -44,6 +45,66 @@ func SchemaForResourceType(t yaml.TypeMeta) *ResourceSchema {
 	return &ResourceSchema{Schema: rs}
 }
 
+// SupplementaryOpenAPIFieldName is the conventional field name (JSON/YAML) containing
+// supplementary OpenAPI definitions.
+const SupplementaryOpenAPIFieldName = "openAPI"
+
+// AddSchemaFromFile reads the file at path and parses the OpenAPI definitions
+// from the field "openAPI"
+func AddSchemaFromFile(path string) error {
+	return AddSchemaFromFileUsingField(path, SupplementaryOpenAPIFieldName)
+}
+
+// AddSchemaFromFileUsingField reads the file at path and parses the OpenAPI definitions
+// from the specified field.  If field is the empty string, use the whole document as
+// OpenAPI.
+func AddSchemaFromFileUsingField(path, field string) error {
+	b, err := ioutil.ReadFile(path)
+	if err != nil {
+		return err
+	}
+
+	// parse the yaml file (json is a subset of yaml, so will also parse)
+	y, err := yaml.Parse(string(b))
+	if err != nil {
+		return err
+	}
+
+	if field != "" {
+		// get the field containing the openAPI
+		m := y.Field(field)
+		if yaml.IsFieldEmpty(m) {
+			// doesn't contain openAPI definitions
+			return nil
+		}
+		y = m.Value
+	}
+
+	oAPI, err := y.String()
+	if err != nil {
+		return err
+	}
+
+	// convert the yaml openAPI to a JSON string by unmarshalling it to an
+	// interface{} and the marshalling it to a string
+	var o interface{}
+	err = yaml.Unmarshal([]byte(oAPI), &o)
+	if err != nil {
+		return err
+	}
+	j, err := json.Marshal(o)
+	if err != nil {
+		return err
+	}
+
+	// add the json schema to the global schema
+	_, err = AddSchema(j)
+	if err != nil {
+		return err
+	}
+	return nil
+}
+
 // AddSchema parses s, and adds definitions from s to the global schema.
 func AddSchema(s []byte) (*spec.Schema, error) {
 	return parse(s)
@@ -296,41 +357,6 @@ func resolve(root interface{}, ref *spec.Ref) (*spec.Schema, error) {
 	}
 }
 
-func PopulateDefsInOpenAPI(s string) error {
-	y, err := yaml.Parse(s)
-	if err != nil {
-		return err
-	}
-	// get the field containing the openAPI
-	f := y.Field("openAPI")
-
-	defs, err := f.Value.String()
-	if err != nil {
-		return err
-	}
-
-	// convert the yaml openAPI to an interface{}
-	// which can be marshalled into json
-	var o interface{}
-	err = yaml.Unmarshal([]byte(defs), &o)
-	if err != nil {
-		return err
-	}
-
-	// convert the interface{} into a json string
-	j, err := json.Marshal(o)
-	if err != nil {
-		return err
-	}
-
-	// add the json schema to the global schema
-	_, err = AddSchema(j)
-	if err != nil {
-		return err
-	}
-	return nil
-}
-
 func rootSchema() *spec.Schema {
 	initSchema()
 	return &globalSchema.schema
diff --git a/kyaml/openapi/openapi_test.go b/kyaml/openapi/openapi_test.go
index 988818f5f..bf0228986 100644
--- a/kyaml/openapi/openapi_test.go
+++ b/kyaml/openapi/openapi_test.go
@@ -5,6 +5,7 @@ package openapi
 
 import (
 	"fmt"
+	"io/ioutil"
 	"testing"
 
 	"github.com/stretchr/testify/assert"
@@ -123,8 +124,8 @@ func TestSchemaForResourceType(t *testing.T) {
 	}
 }
 
-func TestPopulateDefsInOpenAPI_Setter(t *testing.T) {
-	globalSchema = openapiData{}
+func TestAddSchemaFromFile(t *testing.T) {
+	ResetOpenAPI()
 	inputyaml := `
 openAPI:
   definitions:
@@ -134,8 +135,15 @@ openAPI:
           name: image-name
           value: "nginx"
  `
-	err := PopulateDefsInOpenAPI(inputyaml)
+	f, err := ioutil.TempFile("", "openapi-")
+	if !assert.NoError(t, err) {
+		t.FailNow()
+	}
+	if !assert.NoError(t, ioutil.WriteFile(f.Name(), []byte(inputyaml), 0600)) {
+		t.FailNow()
+	}
 
+	err = AddSchemaFromFile(f.Name())
 	if !assert.NoError(t, err) {
 		t.FailNow()
 	}
@@ -153,7 +161,7 @@ openAPI:
 }
 
 func TestPopulateDefsInOpenAPI_Substitution(t *testing.T) {
-	globalSchema = openapiData{}
+	ResetOpenAPI()
 	inputyaml := `
 openAPI:
   definitions:
@@ -178,11 +186,18 @@ openAPI:
           - marker: "IMAGE_TAG"
             ref: "#/definitions/io.k8s.cli.setters.image-tag"
  `
-	err := PopulateDefsInOpenAPI(inputyaml)
 
+	f, err := ioutil.TempFile("", "openapi-")
 	if !assert.NoError(t, err) {
 		t.FailNow()
 	}
+	if !assert.NoError(t, ioutil.WriteFile(f.Name(), []byte(inputyaml), 0600)) {
+		t.FailNow()
+	}
+
+	if !assert.NoError(t, AddSchemaFromFile(f.Name())) {
+		t.FailNow()
+	}
 
 	s, err := GetSchema(`{"$ref": "#/definitions/io.k8s.cli.substitutions.image"}`)
 
@@ -199,3 +214,26 @@ openAPI:
 			` map[marker:IMAGE_TAG ref:#/definitions/io.k8s.cli.setters.image-tag]]]]]`,
 		fmt.Sprintf("%v", s.Schema.Extensions))
 }
+
+func TestAddSchemaFromFile_empty(t *testing.T) {
+	ResetOpenAPI()
+	inputyaml := `
+kind: Example
+ `
+
+	f, err := ioutil.TempFile("", "openapi-")
+	if !assert.NoError(t, err) {
+		t.FailNow()
+	}
+	if !assert.NoError(t, ioutil.WriteFile(f.Name(), []byte(inputyaml), 0600)) {
+		t.FailNow()
+	}
+
+	if !assert.NoError(t, AddSchemaFromFile(f.Name())) {
+		t.FailNow()
+	}
+
+	if !assert.Equal(t, len(globalSchema.schema.Definitions), 0) {
+		t.FailNow()
+	}
+}