add support for reading database url from password

05-example-web-application/api-golang/main.go

@@ -1,6 +1,7 @@
 package main
 
 import (
+	"io/ioutil"
 	"log"
 	"os"
 	"time"
@@ -11,7 +12,16 @@ import (
 )
 
 func init() {
-	errDB := database.InitDB(os.Getenv("DATABASE_URL"))
+	databaseUrl := os.Getenv("DATABASE_URL")
+	if databaseUrl == "" {
+		content, err := ioutil.ReadFile(os.Getenv("DATABASE_URL_FILE"))
+		if err != nil {
+			log.Fatal(err)
+		}
+		databaseUrl = string(content)
+	}
+
+	errDB := database.InitDB(databaseUrl)
 	if errDB != nil {
 		log.Fatalf("⛔ Unable to connect to database: %v\n", errDB)
 	} else {