add schema caching

main.go

@@ -7,6 +7,7 @@ import (
 	"log"
 	"os"
 
+	"github.com/yannh/kubeconform/pkg/cache"
 	"github.com/yannh/kubeconform/pkg/registry"
 	"github.com/yannh/kubeconform/pkg/resource"
 	"github.com/yannh/kubeconform/pkg/validator"
@@ -23,9 +24,11 @@ func validateFile(f io.Reader, regs []*registry.KubernetesRegistry, k8sVersion s
 		return fmt.Errorf("error while parsing: %s", err)
 	}
 
+
 	var schema []byte
 	for _, reg := range regs {
-		schema, err = reg.DownloadSchema(sig.Kind, sig.Version, k8sVersion)
+		downloadSchema := cache.WithCache(reg.DownloadSchema)
+		schema, err = downloadSchema(sig.Kind, sig.Version, k8sVersion)
 		if err == nil {
 			break
 		}

pkg/cache/main.go

@@ -0,0 +1,36 @@
+package cache
+
+import (
+	"fmt"
+	"sync"
+)
+
+var mu sync.Mutex
+var schemas map[string][]byte
+
+func init () {
+	schemas = map[string][]byte {}
+}
+
+func WithCache(downloadSchema func(string, string, string) ([]byte, error)) (func (string, string, string) ([]byte, error)) {
+	return func(resourceKind, resourceAPIVersion, k8sVersion string) ([]byte, error) {
+		cacheKey := fmt.Sprintf("%s-%s-%s", resourceKind, resourceAPIVersion, k8sVersion)
+		mu.Lock()
+		cachedSchema, ok := schemas[cacheKey];
+		mu.Unlock()
+		if ok {
+			return cachedSchema, nil
+		}
+
+		schema, err := downloadSchema(resourceKind, resourceAPIVersion, k8sVersion)
+		if err != nil {
+			return schema, err
+		}
+
+		mu.Lock()
+		schemas[cacheKey] = schema
+		mu.Unlock()
+
+		return schema, nil
+	}
+}