Return error if etcd_endpoints variable is missing

config/config.go

@@ -1,7 +1,8 @@
 package config
 
 import (
-	"log"
+	"fmt"
+	"log/slog"
 
 	"github.com/joho/godotenv"
 	"github.com/kelseyhightower/envconfig"
@@ -9,18 +10,21 @@ import (
 
 // Config contains environment variables.
 type Config struct {
-	EtcdEndpoint  string `envconfig:"ETCD_ENDPOINTS"`
+	EtcdEndpoint string `envconfig:"ETCD_ENDPOINTS"`
 }
 
 // LoadConfig reads environment variables, populates and returns Config.
 func LoadConfig() (*Config, error) {
 	if err := godotenv.Load(); err != nil {
-		log.Println("No .env file found")
+		slog.Warn("No .env file found")
 	}
 
 	var c Config
-
 	err := envconfig.Process("", &c)
 
+	if len(c.EtcdEndpoint) < 1 {
+		err = fmt.Errorf("missing variable ETCD_ENDPOINTS, not set")
+	}
+
 	return &c, err
 }

main.go

@@ -25,7 +25,7 @@ func getArgvFilename() string {
 func main() {
 	_, err := config.LoadConfig()
 	if err != nil {
-		log.Println("Error from config loader", err)
+		log.Fatalf("Error from config loader: %s", err)
 	}
 
 	// setup etcd client