refactor: move gateway and vault packages to internal directory

internal/gateway/config/env.go

@@ -0,0 +1,45 @@
+package config
+
+import (
+	"context"
+
+	"github.com/apple/pkl-go/pkl"
+)
+
+// LoadFromBytes loads the environment from the given bytes
+func LoadFromBytes(data []byte) (Env, error) {
+	text := string(data)
+	return LoadFromString(text)
+}
+
+// LoadFromString loads the environment from the given string
+func LoadFromString(text string) (Env, error) {
+	evaluator, err := pkl.NewEvaluator(context.Background(), pkl.PreconfiguredOptions)
+	if err != nil {
+		return nil, err
+	}
+	defer func() {
+		cerr := evaluator.Close()
+		if err == nil {
+			err = cerr
+		}
+	}()
+	ret, err := Load(context.Background(), evaluator, pkl.TextSource(text))
+	return ret, err
+}
+
+// LoadFromURL loads the environment from the given URL
+func LoadFromURL(url string) (Env, error) {
+	evaluator, err := pkl.NewEvaluator(context.Background(), pkl.PreconfiguredOptions)
+	if err != nil {
+		return nil, err
+	}
+	defer func() {
+		cerr := evaluator.Close()
+		if err == nil {
+			err = cerr
+		}
+	}()
+	ret, err := Load(context.Background(), evaluator, pkl.UriSource(url))
+	return ret, err
+}