feat: load explicit configuration references and remove implicit env overlays

examples/reference/main.go

@@ -2,6 +2,7 @@ package main
 
 import (
 	"context"
+	"flag"
 	"log"
 	"os"
 	"os/signal"
@@ -42,6 +43,7 @@ func registerRoutes(application *omni.App, users service.UserRepository, logger
 }
 
 func main() {
+	flag.Parse()
 	ctx, stop := signal.NotifyContext(context.Background(), os.Interrupt, syscall.SIGTERM)
 	defer stop()
 	if err := runReference(ctx); err != nil {
@@ -49,29 +51,9 @@ func main() {
 	}
 }
 
-func referenceConfig() (omni.Config, error) {
-	settings, err := omni.LoadConfig("")
-	if err != nil {
-		return settings, err
-	}
-	// Preserve the example's loopback default and legacy address variable.
-	if strings.TrimSpace(os.Getenv("GO_OMNI_HTTP_ADDR")) == "" {
-		settings.Address = strings.TrimSpace(os.Getenv("GO_OMNI_ADDR"))
-		if settings.Address == "" {
-			settings.Address = "127.0.0.1:8080"
-		}
-	}
-	if settings.Log.Service == "" {
-		settings.Log.Service = "reference-api"
-	}
-	if settings.Log.Environment == "" {
-		settings.Log.Environment = "local"
-	}
-	if strings.TrimSpace(os.Getenv("GO_OMNI_LOG_OUTPUT")) == "" {
-		settings.Log.Output = "stdout"
-	}
-	return settings, nil
-}
+var configPath = flag.String("config", "examples/reference/config.yaml", "configuration file")
+
+func referenceConfig() (omni.Config, error) { return omni.LoadConfig(*configPath) }
 
 func runReference(ctx context.Context) error {
 	settings, err := referenceConfig()
@@ -106,10 +88,9 @@ func openUsers(ctx context.Context, logger *logx.Logger) (service.UserRepository
 	if strings.TrimSpace(os.Getenv("GO_OMNI_DB_DSN")) == "" {
 		return repository.NewMemoryUsers(), func() error { return nil }, "memory", nil
 	}
-	cfg, err := database.ConfigFromEnv("GO_OMNI_DB_")
-	if err != nil {
-		return nil, nil, "", err
-	}
+	cfg := database.DefaultConfig()
+	cfg.Driver = "mysql"
+	cfg.DSN = os.Getenv("GO_OMNI_DB_DSN")
 	db, err := database.Open(ctx, cfg)
 	if err != nil {
 		return nil, nil, "", err