feat: add resource provider override

pkg/resource_provider.go

@@ -0,0 +1,43 @@
+package pkg
+
+import "sync"
+
+// ResourceProvider supplies template/config bytes by logical name.
+type ResourceProvider func(string) []byte
+
+var resourceProvider struct {
+	sync.RWMutex
+	fn ResourceProvider
+}
+
+// SetResourceProvider installs an external template/config provider.
+func SetResourceProvider(provider ResourceProvider) {
+	resourceProvider.Lock()
+	defer resourceProvider.Unlock()
+	resourceProvider.fn = provider
+}
+
+// ResetResourceProvider removes the external template/config provider.
+func ResetResourceProvider() {
+	SetResourceProvider(nil)
+}
+
+// LoadEmbeddedConfig loads the standalone embedded config without consulting
+// an installed external provider.
+func LoadEmbeddedConfig(typ string) []byte {
+	return loadEmbeddedConfig(typ)
+}
+
+// LoadConfig loads config bytes from the external provider first, then from
+// the embedded templates kept for standalone spray compatibility.
+func LoadConfig(typ string) []byte {
+	resourceProvider.RLock()
+	provider := resourceProvider.fn
+	resourceProvider.RUnlock()
+	if provider != nil {
+		if data := provider(typ); len(data) > 0 {
+			return data
+		}
+	}
+	return loadEmbeddedConfig(typ)
+}

pkg/templates.go

@@ -1,3 +1,6 @@
+//go:build !emptytemplates
+// +build !emptytemplates
+
 package pkg
 
 import (
@@ -6,7 +9,7 @@ import (
 
 var RandomDir = "/g8kZMwp4oeKsL2in"
 
-func LoadConfig(typ string) []byte {
+func loadEmbeddedConfig(typ string) []byte {
 	if typ == "spray_rule" {
 		return encode.MustDeflateDeCompress(encode.Base64Decode("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"))
 	} else if typ == "spray_common" {

pkg/templates_empty.go

@@ -0,0 +1,10 @@
+//go:build emptytemplates
+// +build emptytemplates
+
+package pkg
+
+var RandomDir = ""
+
+func loadEmbeddedConfig(string) []byte {
+	return nil
+}