comp review todo app update (#146)

* new todo frontend

* yarn --> npm

* basic Dockerfile

* add Helm chart for todo list

* backend working

* connect new-app'd frontend to backend via proxy_pass

* move nginx conf

* move nginx conf back

* move helm chart to course repo

* add simple SSR node.js service

* log error message

* fix host typo

* fix dockerfiles

* add link to items page

* improve probe route for todo-backend

* canary probe route for todo-backend

* Dockerfile -> Containerfile todo-backend

* Dockerfile -> Containerfile todo-frontend

* remove commands for containerfile as part of comp review

todo-backend/src/Server.ts

@@ -1,5 +1,5 @@
 import cookieParser from "cookie-parser";
-import express, { Request, Response } from "express";
+import express from "express";
 import "express-async-errors";
 import cors from "cors";
 import { Sequelize } from "sequelize";
@@ -17,6 +17,8 @@ app.use(express.json());
 app.use(express.urlencoded({ extended: true }));
 app.use(cookieParser());
 
+let canary = true;
+
 const sequelize = new Sequelize(dbConnectionOptions);
 sequelize
   .authenticate()
@@ -24,20 +26,20 @@ sequelize
     console.log("Connection has been established successfully.");
   })
   .catch((err) => {
+    canary = false;
     console.error("Unable to connect to the database:", err);
   });
 
+app.get("/", (req, res) => {
+  if (canary) {
+    res.send("OK");
+  } else {
+    res.status(500).send("Experienced an error on startup.");
+  }
+});
+
 // Add APIs
 app.use("/api", BaseRouter);
 
-// Print API errors
-// eslint-disable-next-line @typescript-eslint/no-unused-vars
-app.use((err: Error, req: Request, res: Response) => {
-  console.error(err, true);
-  return res.status(500).json({
-    error: err.message,
-  });
-});
-
 // Export express instance
 export default app;

todo-backend/src/entities/Item.ts

@@ -37,9 +37,9 @@ export const TodoItem = sequelize.define<TodoItemInstance>(
 );
 
 // (re-)creates table (NOT database)
-if (process.env.DATABASE_INIT === "true") {
-  TodoItem.sync({ force: true });
-}
+// if (process.env.DATABASE_INIT === "true") {
+TodoItem.sync({ force: true });
+// }
 
 export async function createTodoItem(todoItem: TodoItemCreationAttributes) {
   return TodoItem.create(todoItem).then((item) => item.get());