Add Schema to Chart and loader

Signed-off-by: Ian Howell <ian.howell0@gmail.com>

pkg/chart/chart.go

@@ -31,6 +31,8 @@ type Chart struct {
 	RawValues []byte
 	// Values are default config for this template.
 	Values map[string]interface{}
+	// Schema is an optional JSON schema for imposing structure on Values
+	Schema map[string]interface{}
 	// Files are miscellaneous files in a chart archive,
 	// e.g. README, LICENSE, etc.
 	Files []*File

pkg/chart/loader/load.go

@@ -90,6 +90,11 @@ func LoadFiles(files []*BufferedFile) (*chart.Chart, error) {
 				return c, errors.Wrap(err, "cannot load values.yaml")
 			}
 			c.RawValues = f.Data
+		case f.Name == "values.schema.yaml":
+			c.Schema = make(map[string]interface{})
+			if err := yaml.Unmarshal(f.Data, &c.Schema); err != nil {
+				return c, errors.Wrap(err, "cannot load values.schema.yaml")
+			}
 		case strings.HasPrefix(f.Name, "templates/"):
 			c.Templates = append(c.Templates, &chart.File{Name: f.Name, Data: f.Data})
 		case strings.HasPrefix(f.Name, "charts/"):

pkg/chart/loader/load_test.go

@@ -78,6 +78,10 @@ icon: https://example.com/64x64.png
 			Name: "values.yaml",
 			Data: []byte("var: some values"),
 		},
+		{
+			Name: "values.schema.yaml",
+			Data: []byte("type: Values"),
+		},
 		{
 			Name: "templates/deployment.yaml",
 			Data: []byte("some deployment"),
@@ -101,6 +105,10 @@ icon: https://example.com/64x64.png
 		t.Error("Expected chart values to be populated with default values")
 	}
 
+	if c.Schema["type"] != "Values" {
+		t.Error("Expected chart schema to be populated with default values")
+	}
+
 	if len(c.Templates) != 2 {
 		t.Errorf("Expected number of templates == 2, got %d", len(c.Templates))
 	}