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:
![..... 2023-02-12 13:07:41.342 UTC [1] LOG: database system is ready to accept connections](https://media2.dev.to/dynamic/image/width=800%2Cheight=%2Cfit=scale-down%2Cgravity=auto%2Cformat=auto/https%3A%2F%2Fdev-to-uploads.s3.amazonaws.com%2Fuploads%2Farticles%2Ficy9s09od5sdja90drft.png)
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.
Top comments (73)
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.
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!
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!
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! 💙
A typescript version would be great! Thanks for your effort.
Awesome! 😄
it's on the todo list. thanks
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?
try docker ps -a. can you see the containers up and running?
Oh, this is because i missed the
next()function call.oh I see! glad you fixed it
It is actually running
in the index.js, i tried to commented out these lines and it is working now:
I still don't understand what happened. Any pointers / explanation would be appreciated much.
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
fixed, thanks!
Thank you Francesco.
you are welcome Mude
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?
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
Oh okay. Thank you!
you are welcome
Great post!
thanks Bobby!
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:
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?
Hi Francesco
I have set up a codesandbox VM, to try and emulate this tutorial.
I see that your table is called:
But you connect via:
How does your code find the Users table?
I am new at coding. Will try it on the weekend. Thank you for this tutorial.
please let me know if it worked. thank you
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.
amazing, glad it helped. do you mean a spelling mistake on your end or in the tutorial?
A few weeks ago, I've discover postgrest, just crazy easy. postgrest.org/en/stable/index.html
It's also open data, directly query your postgresql db just using URIs.
Nice write up! If I ever use this stack I’ll be sure to keep this article nearby.
thank you Toul!