Add schema validation to helm lint

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

pkg/action/lint_test.go

@@ -29,6 +29,8 @@ var (
 	invalidArchivedChartPath     = "../../cmd/helm/testdata/testcharts/invalidcompressedchart0.1.0.tgz"
 	chartDirPath                 = "../../cmd/helm/testdata/testcharts/decompressedchart/"
 	chartMissingManifest         = "../../cmd/helm/testdata/testcharts/chart-missing-manifest"
+	chartSchema                  = "../../cmd/helm/testdata/testcharts/chart-with-schema"
+	chartSchemaNegative          = "../../cmd/helm/testdata/testcharts/chart-with-schema-negative"
 )
 
 func TestLintChart(t *testing.T) {
@@ -47,4 +49,10 @@ func TestLintChart(t *testing.T) {
 	if _, err := lintChart(chartMissingManifest, values, namespace, strict); err == nil {
 		t.Error("Expected a chart parsing error")
 	}
+	if _, err := lintChart(chartSchema, values, namespace, strict); err != nil {
+		t.Error(err)
+	}
+	if _, err := lintChart(chartSchemaNegative, values, namespace, strict); err != nil {
+		t.Error(err)
+	}
 }

pkg/lint/rules/values.go

@@ -19,6 +19,7 @@ package rules
 import (
 	"os"
 	"path/filepath"
+	"strings"
 
 	"github.com/pkg/errors"
 
@@ -48,6 +49,18 @@ func validateValuesFileExistence(valuesPath string) error {
 }
 
 func validateValuesFile(valuesPath string) error {
-	_, err := chartutil.ReadValuesFile(valuesPath)
+	values, err := chartutil.ReadValuesFile(valuesPath)
+	if err != nil {
 		return errors.Wrap(err, "unable to parse YAML")
 	}
+
+	schemaPath := strings.Replace(valuesPath, ".yaml", ".schema.yaml", 1)
+	schema, err := chartutil.ReadSchemaFile(schemaPath)
+	if len(schema) == 0 {
+		return nil
+	}
+	if err != nil {
+		return err
+	}
+	return chartutil.ValidateAgainstSchema(values, schema)
+}