Francesco Ciulla

Posted on Feb 12, 2023 • Edited on Apr 18, 2023

JavaScript CRUD Rest API using Nodejs, Express, Sequelize, Postgres, Docker and Docker Compose

#beginners #javascript #webdev #docker

Let's create a CRUD rest API in JavaScript, using:

Node.js
Express
Sequelize
Postgres
Docker
Docker Compose

All the code is available in the GitHub repository (link in the video description): https://youtube.com/live/Uv-jMWV29rU

Intro

Here is a schema of the architecture of the application we are going to create:

We will create 5 endpoints for basic CRUD operations:

Create
Read all
Read one
Update
Delete

We will create a Node.js application using:

Express as a framework
Sequelize as an ORM

We will Dockerize the Node.js application
We will have a Postgres istance, we will test it with Tableplus
We will create a docker compose file to run both the services
We will test the APIs with Postman

Step-by-step guide

Here is a step-by step guide.

create a new folder



mkdir node-crud-api

step into it



cd node-crud-api

initialize a new npm project



npm init -y

install the dependencies



npm i express pg sequelize

express is the Node.js framework
pg is a driver for a connection with a Postgres db
sequelize is the ORM so we avoid typing SQL queries

create 4 folders



mkdir controllers routes util models

Open the folder with your favorite IDE. If you have Visual Studio Code, you can type this from the terminal:



code .

You should now have a folder similar to this one:

Now let's start coding.

Database connection

Create a file called "database.js" inside the "util" folder.

This file will contain the internal configuration to allow the connection between the Node.js application and the running Postgres instance.

Populate the util/database.js file



const Sequelize = require('sequelize');

const sequelize = new Sequelize(
    process.env.PG_DB,
    process.env.PG_USER,
    process.env.PG_PASSWORD,
    {
        host: process.env.PG_HOST,
        dialect: 'postgres',
    }
);

module.exports = sequelize;

User model

Create a file called "user.js" inside the "models" folder.

This file will contain the model, in this case a user with an auto-incremented id, a name and an email.

Populate the models/user.js file:



const Sequelize = require('sequelize');
const db = require('../util/database');

const User = db.define('user', {
    id: {
        type: Sequelize.INTEGER,
        autoIncrement: true,
        allowNull: false,
        primaryKey: true
    },
    name: Sequelize.STRING,
    email: Sequelize.STRING
});

module.exports = User;

Controllers

This is the file that contains all the functions to execute in order to interact with the database and have the 4 basic functionalities:

Create a file called "users.js" inside the "controllers" folder

Populate the controllers/users.js file



const User = require('../models/user');

// CRUD Controllers

//get all users
exports.getUsers = (req, res, next) => {
    User.findAll()
        .then(users => {
            res.status(200).json({ users: users });
        })
        .catch(err => console.log(err));
}

//get user by id
exports.getUser = (req, res, next) => {
    const userId = req.params.userId;
    User.findByPk(userId)
        .then(user => {
            if (!user) {
                return res.status(404).json({ message: 'User not found!' });
            }
            res.status(200).json({ user: user });
        })
        .catch(err => console.log(err));
}

//create user
exports.createUser = (req, res, next) => {
  const name = req.body.name;
  const email = req.body.email;
  User.create({
    name: name,
    email: email
  })
    .then(result => {
      console.log('Created User');
      res.status(201).json({
        message: 'User created successfully!',
        user: result
      });
    })
    .catch(err => {
      console.log(err);
    }); 
}

//update user
exports.updateUser = (req, res, next) => {
  const userId = req.params.userId;
  const updatedName = req.body.name;
  const updatedEmail = req.body.email;
  User.findByPk(userId)
    .then(user => {
      if (!user) {
        return res.status(404).json({ message: 'User not found!' });
      }
      user.name = updatedName;
      user.email = updatedEmail;
      return user.save();
    })
    .then(result => {
      res.status(200).json({message: 'User updated!', user: result});
    })
    .catch(err => console.log(err));
}

//delete user
exports.deleteUser = (req, res, next) => {
  const userId = req.params.userId;
  User.findByPk(userId)
    .then(user => {
      if (!user) {
        return res.status(404).json({ message: 'User not found!' });
      }
      return User.destroy({
        where: {
          id: userId
        }
      });
    })
    .then(result => {
      res.status(200).json({ message: 'User deleted!' });
    })
    .catch(err => console.log(err));
}

Routes

Create a file called "users.js" inside the "routes" folder.

Populate the routes/users.js file



const controller = require('../controllers/users');
const router = require('express').Router();

// CRUD Routes /users
router.get('/', controller.getUsers); // /users
router.get('/:userId', controller.getUser); // /users/:userId
router.post('/', controller.createUser); // /users
router.put('/:userId', controller.updateUser); // /users/:userId
router.delete('/:userId', controller.deleteUser); // /users/:userId

module.exports = router;

Index file

To run our application we need to create on more file at the root level. this is the file that will be executed by the docker container.

in the root folder, create a file called index.js

Populate the "index.js file":



const express = require('express');
const bodyparser = require('body-parser');
const sequelize = require('./util/database');
const User = require('./models/user');

const app = express();

app.use(bodyparser.json());
app.use(bodyparser.urlencoded({ extended: false }));

app.use((req, res, next) => {
  res.setHeader('Access-Control-Allow-Origin', '*');
  res.setHeader('Access-Control-Allow-Methods', 'GET, POST, PUT, DELETE');
  next();
});

//test route
app.get('/', (req, res, next) => {
  res.send('Hello World');
});

//CRUD routes
app.use('/users', require('./routes/users'));

//error handling
app.use((error, req, res, next) => {
  console.log(error);
  const status = error.statusCode || 500;
  const message = error.message;
  res.status(status).json({ message: message });
});

//sync database
sequelize
  .sync()
  .then(result => {
    console.log("Database connected");
    app.listen(3000);
  })
  .catch(err => console.log(err));

Docker Part

Let's create 3 more files at the root level:

.dockerignore (it starts with a dot)
Dockerfile (capital D)
docker-compose.yml

The structure should look like this:

the .dockerignore will contain a single line:



node_modules

The Dockerfile

To create a Docker image we need a simple yet powerfule file. That's called "Dockerfile" (capital D). We might use a different name but let's keep things simple for now.



FROM node:14

# Create app directory
WORKDIR /app

COPY package*.json ./

RUN npm install

# Bundle app source
COPY . .

EXPOSE 3000

CMD [ "node", "index.js" ]

Docker compose file

To run multiple services an easy way is to create a file called "docker-compose.yml"

The docker-compose.yml file:



version: "3.9"

services:
  node_app:
    container_name: node_app
    build: .
    image: francescoxx/node_live_app
    ports:
      - "3000:3000"
    environment:
      - PG_DB=node_live_db
      - PG_USER=francesco
      - PG_PASSWORD=12345
      - PG_HOST=node_db
    depends_on:
      - node_db

  node_db:
    container_name: node_db
    image: postgres:12
    ports:
      - "5432:5432"
    environment:
      - POSTGRES_DB=node_live_db
      - POSTGRES_USER=francesco
      - POSTGRES_PASSWORD=12345
    volumes:
      - node_db_data:/var/lib/postgresql/data

volumes:
  node_db_data: {}

Build the Docker image and run the docker containers

Run Postgres in a container

First, let's run the postgres container:



docker compose up -d node_db

To check the logs, we can type:



docker compose logs

you should get an output similar to this one:

if we see "database system is ready to accept connections" we are good to go!

Let's test it using TablePlus.

Click on the + to create a new connection

copy the values from the docker-compose.yml file. (password is 12345 if you left the values as they are)

Build and run the Docker service

Second, let's build our Docker iamge:



docker compose build

finally, let's start the service:



docker compose up node_app

This should be the output on the terminal

Test the app with Postman

Let's test the app using Postman.

Make a GET request to localhost:3000

Make a GET request to localhost:3000/users

We should have an empty array as a response

Let's create 3 users: aaa, bbb, and ccc

Let's check again all the users:

Make a GET request to localhost:3000/users

We should see 3 users:

Let's get a single user, for example the user 2

Make a GET request to localhost:3000/users/2

Let's update an existing user, for example the same user 2

Make a PUT reqeust to localhost:3000/users/2 with a different body

Finally, let's delete the user number 3

Make a DELETE reuqest to localhost:3000/users/3

We can also check the values using TablePlus

Conclusion

This is a basic example of how you can build a CRUD rest API using Node.js, Express, Sequelize, Postres, Docker, and Docker Compose.

All the code is available in the GitHub repository (link in the video description): https://youtube.com/live/Uv-jMWV29rU

That's all.
If you have any question, drop a comment below.

Francesco

Top comments (73)

Anton Fridlund • Feb 16 '23

Hello!
I think this read was quite interesting, good guide.

There were however a few things i noticed that I don't often see in modern JavaScript programming.

Usually you would avoid chaining calls with ".then" since it is bad practice, use "await" instead. Is there a reason why you chain your calls like this even when it's bad practice?

Exporting arrow functions in the controller leads to poor readability and is also not a common way to handle controllers. You would probably want to create a class that represents the controller and export that class. Do you have a reason for exporting arrow functions?

Something that I was wondering throughout the guide was why you use "require" instead of "import", basically why commonjs instead of esm? Commonjs is since long dying and i would not recommend using it.

The JavaScript code in the guide seems to be quite old and I would be careful if I were to use it.

Francesco Ciulla • Feb 16 '23

nice breakdown Anton! this is not optimized and it's meant to get things fast. the focus here was more on creating the endpoints and the docker image and the connection with the db.

about the async await, I just used the suggested code, but in other guides I used the await, honestly I prefer that one

this is not meant to be a production ready code, but it's a way to undesrtand the basics!

Thanks for your feedback, I will probably level up the code in the next guide!

Anton Fridlund • Feb 16 '23

Thank you for the explanation!
I was happy to see such a thorough guide as a whole.

It was interesting to see how you containerize the application and I also liked the testing of the end product using Postman and TablePlus, great tools.

Thank you for the guide!

Francesco Ciulla • Feb 16 '23

my idea was to start with this and maybe focus more on the upcoming Typescript example. this article is a breakthrough of something I coded live on youtube.

Thank yuo for your feedback, highly appreciated instead of the usual "asweome" comment! 💙

Karl Krasnowsky • Feb 16 '23

A typescript version would be great! Thanks for your effort.
Awesome! 😄

Francesco Ciulla • Feb 16 '23

it's on the todo list. thanks

Edward Fernando • Feb 17 '23

Thanks for this tutorial @francescoxx

When I run this on my machine, although the server is started, it is stuck when calling the endpoint. It does not returning the response.

Im currently using mac with m1 chip. Any pointers about this?

Francesco Ciulla • Feb 17 '23

try docker ps -a. can you see the containers up and running?

Edward Fernando • Feb 17 '23 • Edited

Oh, this is because i missed the next() function call.

app.use((req, res, next) => {
    res.setHeader('Access-Control-Allow-Origin', '*');
    res.setHeader('Access-Control-Allow-Methods', 'GET, POST, PUT, DELETE');
    next();
});

Francesco Ciulla • Feb 18 '23

oh I see! glad you fixed it

Edward Fernando • Feb 17 '23

➜  ~ docker ps -a
CONTAINER ID   IMAGE               COMMAND                  CREATED        STATUS          PORTS                              NAMES
d3f626718969   efs/node_live_app   "docker-entrypoint.s…"   15 hours ago   Up 39 seconds   3000/tcp, 0.0.0.0:3333->3333/tcp   node_app
3c423213aeff   postgres:12         "docker-entrypoint.s…"   15 hours ago   Up 15 hours     0.0.0.0:5432->5432/tcp             node_db

It is actually running

Edward Fernando • Feb 17 '23

in the index.js, i tried to commented out these lines and it is working now:

// app.use((req, res, next) => {
//     res.setHeader('Access-Control-Allow-Origin', '*');
//     res.setHeader('Access-Control-Allow-Methods', 'GET, POST, PUT, DELETE');
// });

I still don't understand what happened. Any pointers / explanation would be appreciated much.

Mude Shoban Babu • Apr 18 '23

Thanks so much for detailed course. Just a correction in link,

The youtube link that you have kept in the bottom of the course content takes to "Build a CRUD Rest API with Kotlin, Postgres, Docker and docker compose" instead of "JavaScript CRUD Rest API using Nodejs, Express, Sequelize, Postgres, Docker and Docker Compose", it should be updated to https://www.youtube.com/watch?v=Uv-jMWV29rU&t=236s

Francesco Ciulla • Apr 18 '23

fixed, thanks!

Mude Shoban Babu • Apr 18 '23

Thank you Francesco.

Francesco Ciulla • Apr 18 '23

you are welcome Mude

Hisham Akmal • Feb 18 '23

Well written and documented. Thanks a ton! But i've got one doubt regarding docker compose and docker build. Arent we supposed to build the image first and name it node_live_app using the docker build command and then execute docker compose build?

Francesco Ciulla • Feb 18 '23

no, docker compose build just builds the image. you can even just run docker compose up --build , or docker compose up.

I just did it to show the step-by-step commands to make it clearer

Hisham Akmal • Feb 23 '23

Oh okay. Thank you!

Francesco Ciulla • Feb 24 '23

you are welcome

Bobby Iliev • Feb 13 '23

Great post!

Francesco Ciulla • Feb 13 '23

thanks Bobby!

Charles Robertson • Feb 15 '23

This is a first class tutorial. Very clear and precise.
I’ve been a server side Dev for nearly 20 years, using a language called Coldfusion. In Coldfusion we have a tag called CFQUERY, which we can write SQL, inside.
So, for example:

<cfquery name="getEmployees" datasource="cfdocexamples">
 SELECT FIRSTNAME,LASTNAME,EMAIL,PHONE
 FROM EMPLOYEES
</cfquery>

Obviously, you can write extremely complex SQL queries here.
I have only been using NodeJs for a few years now and have always wondered how easy it is to increase the complexity of the SQL query in a NodeJS Rest API application?

CRUD is all very well and is great for highlighting the basics, but, in the real world, business requirements might warrant more complexity?

Charles Robertson • Feb 24 '23

Hi Francesco

I have set up a codesandbox VM, to try and emulate this tutorial.

I see that your table is called:

Users

But you connect via:

const User = define("user", {
  id: {
    type: INTEGER,
    autoIncrement: true,
    allowNull: false,
    primaryKey: true,
  },
  name: STRING,
  email: STRING,
});

How does your code find the Users table?

KayBeckmann • Feb 13 '23

I am new at coding. Will try it on the weekend. Thank you for this tutorial.

Francesco Ciulla • Feb 13 '23

please let me know if it worked. thank you

KayBeckmann • Mar 2 '23

Finaly I tested it today.
It worked very well.
a little spelling mistakes in "docker-compose" for starting the second container, but this was easy to fix.
now I can make a little backend for testing in local network :D
Thank you so much.