Try 4

dao/persondao.test.js

@@ -27,7 +27,7 @@ var pool = mysql.createPool({
 
 var pool = mysql.createPool({
   connectionLimit: 1,
-  host: "localhost", //"localhost" if u wonna be on local db
+  host: "mysql", //"localhost" if u wonna be on local db
   user: "root",
   password: "secret",
   database: "supertestdb",