Refactored config system again

common/util.go

@@ -293,15 +293,15 @@ func MakeCredential(username, groupname string) (*syscall.Credential, error) {
 	return &syscall.Credential{Uid: uid, Gid: gid}, nil
 }
 
-func EffectiveDataRoot(config *AppConfig, domainConfig *DomainConfig) string {
+// EffectiveDataRoot resolves the data root for a domain. The per-domain
+// override takes precedence; otherwise the app-level data root is used; if
+// both are empty, the current working directory is used.
+func EffectiveDataRoot(config *AppConfig, domainDataRoot string) string {
 	if config == nil {
 		return ""
 	}
-	if domainConfig == nil {
-		return ""
-	}
 
-	if domainConfig.Certificates.DataRoot == "" {
+	if domainDataRoot == "" {
 		if config.Certificates.DataRoot == "" {
 			workDir, err := os.Getwd()
 			if err != nil {
@@ -311,7 +311,7 @@ func EffectiveDataRoot(config *AppConfig, domainConfig *DomainConfig) string {
 		}
 		return config.Certificates.DataRoot
 	}
-	return domainConfig.Certificates.DataRoot
+	return domainDataRoot
 }
 
 var fqdnRegex = regexp.MustCompile(`^(?i:[a-z0-9](?:[a-z0-9-]{0,61}[a-z0-9])?\.)+[a-z]{2,}$`)