By the end of this, you will understand and create a simple yet complete full stack app using the following:
- Next.js 14 (TypeScript)
- Tailwind CSS
- Flask (Python) + SQLAlchemy (ORM)
- PostgreSQL
- Docker
- Docker Compose
MANY technologies, but we'll keep the example as basic as possible to make it understandable.
We will proceed with a bottom-up approach, starting with the database and ending with the frontend.
If you prefer a video version
All the code is available for free on GitHub (link in video description).
Architecture
Before we start, here is a simple schema explaining the app's architecture.
The frontend is a Next.js app with TypeScript and Tailwind CSS.
The backend is written in Python, using Flask and SQLAlchemy.
The database is PostgreSQL. We will use Docker to run the database, the backend, and also the frontend (you can also use Vercel). We will use Docker Compose to run the frontend, the backend, and the database together.
Prerequisites
- Basic knowledge of what is a frontend, a backend, an API, and a database
- Docker installed on your machine
- Python installed on your machine
- (optional) Postman or any other tool to make HTTP requests
1. Preparation
Create any folder you want, and then open it with your favorite code editor.
mkdir <YOUR_FOLDER>
cd <YOUR_FOLDER>
code .
Initialize a git repository.
git init
touch .gitignore
Populate the .gitignore
file with the following content:
*node_modules
Create a file called compose.yml
in the project's root.
touch compose.yml
Your projects should look like this:
We are ready to create the fullstack app and build it from the bottom up, starting with the database.
After each step, we will test the app's current state to ensure that everything is working as expected.
2. Database
We will use Postgres but not install it on our machine. Instead, we will use Docker to run it in a container. This way, we can easily start and stop the database without installing it on our machine.
Open the file compose.yml
and add the following content:
services:
db:
container_name: db
image: postgres:13
environment:
POSTGRES_USER: postgres
POSTGRES_PASSWORD: postgres
POSTGRES_DB: postgres
ports:
- 5432:5432
volumes:
- pgdata:/var/lib/postgresql/data
volumes:
pgdata: {}
then type in your terminal
docker compose up -d
This will pull the Postgres image from Docker Hub and start the container. The -d
flag means that the container will run in detached mode so we can continue to use the terminal.
Check if the container is running:
docker ps -a
You should see the container running.
Step into the db container
docker exec -it db psql -U postgres
Now that you are in the Postgres container, you can type:
\l
\dt
And you should see no relations.
You can leave the tab open. We will use it later.
3. Backend
The first step is done. Now, we will create the backend. We will use Go and Mux.
Create a new folder called backend
and step into it:
mkdir backend
cd backend
Create 3 files
touch requirements.txt app.py flask.dockerfile
Your project should look like this:
đī¸ requirements.txt file
The requirements.txt file contains all the dependencies of the project. In our case we will need just 3.
Let's add them to the requirements.txt file:
flask
psycopg2-binary
Flask-SQLAlchemy
Flask-CORS
flask
is the Python web framework we are gonna use.
psycopg2-binary
is the driver to make the connection with the Postgres database.
Flask-SQLAlchemy
is the ORM to make the queries to the database.
Flask-CORS
is a Flask extension for handling Cross Origin Resource Sharing (CORS), making cross-origin AJAX possible.
đ app.py file
The app.py file is the main file of the application: it contains all the endpoints and the logic of the application.
Populate the app.py file as follows:
from flask import Flask, request, jsonify, make_response
from flask_sqlalchemy import SQLAlchemy
from flask_cors import CORS
from os import environ
app = Flask(__name__)
CORS(app) # Enable CORS for all routes
app.config['SQLALCHEMY_DATABASE_URI'] = environ.get('DATABASE_URL')
db = SQLAlchemy(app)
class User(db.Model):
__tablename__ = 'users'
id = db.Column(db.Integer, primary_key=True)
name = db.Column(db.String(80), unique=True, nullable=False)
email = db.Column(db.String(120), unique=True, nullable=False)
def json(self):
return {'id': self.id,'name': self.name, 'email': self.email}
db.create_all()
#create a test route
@app.route('/test', methods=['GET'])
def test():
return make_response(jsonify({'message': 'test route'}), 200)
# create a user
@app.route('/api/flask/users', methods=['POST'])
def create_user():
try:
data = request.get_json()
new_user = User(name=data['name'], email=data['email'])
db.session.add(new_user)
db.session.commit()
return jsonify({
'id': new_user.id,
'name': new_user.name,
'email': new_user.email
}), 201
except Exception as e:
return make_response(jsonify({'message': 'error creating user', 'error': str(e)}), 500)
# get all users
@app.route('/api/flask/users', methods=['GET'])
def get_users():
try:
users = User.query.all()
users_data = [{'id': user.id, 'name': user.name, 'email': user.email} for user in users]
return jsonify(users_data), 200
except Exception as e:
return make_response(jsonify({'message': 'error getting users', 'error': str(e)}), 500)
# get a user by id
@app.route('/api/flask/users/<int:id>', methods=['GET'])
def get_user(id):
try:
user = User.query.filter_by(id=id).first()
if user:
return make_response(jsonify({'user': user.json()}), 200)
return make_response(jsonify({'message': 'user not found'}), 404)
except Exception as e:
return make_response(jsonify({'message': 'error getting user', 'error': str(e)}), 500)
# update a user
@app.route('/api/flask/users/<int:id>', methods=['PUT'])
def update_user(id):
try:
user = User.query.filter_by(id=id).first()
if user:
data = request.get_json()
user.name = data['name']
user.email = data['email']
db.session.commit()
return make_response(jsonify({'message': 'user updated'}), 200)
return make_response(jsonify({'message': 'user not found'}), 404)
except Exception as e:
return make_response(jsonify({'message': 'error updating user', 'error': str(e)}), 500)
# delete a user
@app.route('/api/flask/users/<int:id>', methods=['DELETE'])
def delete_user(id):
try:
user = User.query.filter_by(id=id).first()
if user:
db.session.delete(user)
db.session.commit()
return make_response(jsonify({'message': 'user deleted'}), 200)
return make_response(jsonify({'message': 'user not found'}), 404)
except Exception as e:
return make_response(jsonify({'message': 'error deleting user', 'error': str(e)}), 500)
For an explanation, check: https://youtu.be/njNXTM6L0wc
We are importing:
- Flask as a framework
- request to handle the HTTP
- jsonify to handle the json format, not native in Python
- make_response to handle the HTTP responses
- flask_sqlalchemy to handle the db queries
- environ to handle the environment variables
- CORS to handle the Cross Origin Resource Sharing
Then we are creating the Flask app, configuring the database bu setting an environment variable called 'DATABASE_URL'. We will set it later in the docker-compose.yml file.
Then we are creating a User class with an id, a name and an email. the id will be autoincremented automatically by SQLAlchemy when we will create the users. the tablename = 'users' line is to define the name of the table in the database
We are creating Flask app, configuring the database bu setting an environment variable called 'DB_URL'. We will set it later in the docker-compose.yml file.
Then we are creating a User class with an id, a name and an email. the id will be autoincremented automatically by SQLAlchemy when we will create the users. the tablename = 'users' line is to define the name of the table in the database
An important line is db.create_all(). This will synchronize the database with the model defined, for example creating an "users" table.
Then we have 6 endpoints
test: just a test route
create a user: create a user with a name and an email
get all users: get all the users in the database
get one user: get one user by id
update one user: update one user by id
delete one user: delete one user by id
All the routes have error handling, for example if the user is not found, we will return a 404 HTTP response.
You can check a video-explanation here
đŗ Dockerize the Python app
The flask.dockerfile file is the file that will be used to containerize the Flask application.
Create a file called flask.dockerfile
in the backend
folder and add the following content:
FROM python:3.6-slim-buster
WORKDIR /app
COPY requirements.txt ./
RUN pip install -r requirements.txt
COPY . .
EXPOSE 4000
CMD [ "flask", "run", "--host=0.0.0.0", "--port=4000"]
FROM
sets the base image to use. In this case we are using the python 3.6 slim buster image
WORKDIR
sets the working directory inside the image
COPY requirements.txt ./
copies the requirements.txt file to the working directory
RUN pip install -r requirements.txt
installs the requirements
COPY . .
copies all the files in the current directory to the working directory
EXPOSE 4000
exposes the port 4000
CMD [ "flask", "run", "--host=0.0.0.0", "--port=4000"]
sets the command to run when the container starts
For an explanation, check https://youtu.be/njNXTM6L0wc
đ update the compose.yml file
Update the compose.yml
file in the project's root, adding the flaskapp
service.
Below the updated version:
services:
flaskapp:
container_name: flaskapp
image: flaskapp:1.0.0
build:
context: ./backend
dockerfile: flask.dockerfile
ports:
- '4000:4000'
restart: always
environment:
- DATABASE_URL=postgresql://postgres:postgres@db:5432/postgres
depends_on:
- db
db:
container_name: db
image: postgres:13
restart: always
environment:
POSTGRES_USER: postgres
POSTGRES_PASSWORD: postgres
POSTGRES_DB: postgres
ports:
- 5432:5432
volumes:
- pgdata:/var/lib/postgresql/data
volumes:
pgdata:
For an explanation, check: https://youtu.be/njNXTM6L0wc
Build the image and run the container
Now, let's build the image and run the container:
docker compose build
docker compose up -d flaskapp
docker ps -a
We are now ready to test the backend.
đ§Ē Test the backend
We are now ready to test the backend.
You can use Postman or any other tool to make HTTP requests.
get all
Yoy can get all the users, but making a GET request to http://localhost:4000/api/flask/users
Create a new user
You can create a new user, but making a POST request to http://localhost:4000/api/flask/users
You can create 2 more users, to have a total of 3 users.
Let's check the database:
docker exec -it db psql -U postgres
select * from users;
update and delete a user
You can update a user, but making a PUT request to http://localhost:4000/api/flask/users/3
You can delete a user, but making a DELETE request to http://localhost:4000/api/flask/users/3
4. Frontend
Now that we have the backend up and running, we can proceed with the frontend.
We will use Next.js 14 with TypeScript and Tailwind.
From the root folder of the project, run this command:
npx create-next-app@latest --no-git
We use the --no-git flag because we already initialized a git repository at the project's root.
As options:
- What is your project named?
frontend
- TypeScript?
Yes
- EsLint?
Yes
- Tailwind CSS?
Yes
- Use the default directory structure?
Yes
- App Router?
No
(not needed for this project) - Customize the default import alias?
No
This should create a new Next.js project in about one minute.
Step into the frontend folder:
cd frontend
Install Axios, we will use it to make HTTP requests (be sure to be in the frontend
folder):
npm i axios
Before we proceed, try to run the project:
npm run dev
And open your browser at http://localhost:3000
. You should see the default Next.js page.
đī¸ Modify the styles/global.css file
In the src/frontend/src/styles/globals.css
file, replace the content with this one (to avoid some problems with Tailwind):
@tailwind base;
@tailwind components;
@tailwind utilities;
:root {
--foreground-rgb: 0, 0, 0;
--background-start-rgb: 214, 219, 220;
--background-end-rgb: 255, 255, 255;
}
body {
color: rgb(var(--foreground-rgb));
background: linear-gradient(to bottom, transparent, rgb(var(--background-end-rgb))) rgb(var(--background-start-rgb));
}
Create new components
cd src
mkdir components
touch CardComponent.tsx UserInterface.tsx
In the /frontend/src
folder, create a new folder called components
and inside it create a new file called CardComponent.tsx
and add the following content:
import React from 'react';
interface Card {
id: number;
name: string;
email: string;
}
const CardComponent: React.FC<{ card: Card }> = ({ card }) => {
return (
<div className="bg-white shadow-lg rounded-lg p-2 mb-2 hover:bg-gray-100">
<div className="text-sm text-gray-600">Id: {card.id}</div>
<div className="text-lg font-semibold text-gray-800">{card.name}</div>
<div className="text-md text-gray-700">{card.email}</div>
</div>
);
};
export default CardComponent;
Create a UserInterface component
In the /frontend/src/components
folder, create a file called UserInterface.tsx
and add the following content:
import React, { useState, useEffect } from 'react';
import axios from 'axios';
import CardComponent from './CardComponent';
interface User {
id: number;
name: string;
email: string;
}
interface UserInterfaceProps {
backendName: string;
}
const UserInterface: React.FC<UserInterfaceProps> = ({ backendName }) => {
const apiUrl = process.env.NEXT_PUBLIC_API_URL || 'http://localhost:4000';
const [users, setUsers] = useState<User[]>([]);
const [newUser, setNewUser] = useState({ name: '', email: '' });
const [updateUser, setUpdateUser] = useState({ id: '', name: '', email: '' });
const backgroundColors: { [key: string]: string } = {
flask: 'bg-blue-500',
};
const buttonColors: { [key: string]: string } = {
flask: 'bg-blue-700 hover:bg-blue-600',
};
const bgColor = backgroundColors[backendName as keyof typeof backgroundColors] || 'bg-gray-200';
const btnColor = buttonColors[backendName as keyof typeof buttonColors] || 'bg-gray-500 hover:bg-gray-600';
// Fetch users
useEffect(() => {
const fetchData = async () => {
try {
const response = await axios.get(`${apiUrl}/api/${backendName}/users`);
setUsers(response.data.reverse());
} catch (error) {
console.error('Error fetching data:', error);
}
};
fetchData();
}, [backendName, apiUrl]);
// Create a user
const createUser = async (e: React.FormEvent<HTMLFormElement>) => {
e.preventDefault();
try {
const response = await axios.post(`${apiUrl}/api/${backendName}/users`, newUser);
setUsers([response.data, ...users]);
setNewUser({ name: '', email: '' });
} catch (error) {
console.error('Error creating user:', error);
}
};
// Update a user
const handleUpdateUser = async (e: React.FormEvent<HTMLFormElement>) => {
e.preventDefault();
try {
await axios.put(`${apiUrl}/api/${backendName}/users/${updateUser.id}`, { name: updateUser.name, email: updateUser.email });
setUpdateUser({ id: '', name: '', email: '' });
setUsers(
users.map((user) => {
if (user.id === parseInt(updateUser.id)) {
return { ...user, name: updateUser.name, email: updateUser.email };
}
return user;
})
);
} catch (error) {
console.error('Error updating user:', error);
}
};
// Delete a user
const deleteUser = async (userId: number) => {
try {
await axios.delete(`${apiUrl}/api/${backendName}/users/${userId}`);
setUsers(users.filter((user) => user.id !== userId));
} catch (error) {
console.error('Error deleting user:', error);
}
};
return (
<div className={`user-interface ${bgColor} ${backendName} w-full max-w-md p-4 my-4 rounded shadow`}>
<img src={`/${backendName}logo.svg`} alt={`${backendName} Logo`} className="w-20 h-20 mb-6 mx-auto" />
<h2 className="text-xl font-bold text-center text-white mb-6">{`${backendName.charAt(0).toUpperCase() + backendName.slice(1)} Backend`}</h2>
{/* Form to add new user */}
<form onSubmit={createUser} className="mb-6 p-4 bg-blue-100 rounded shadow">
<input
placeholder="Name"
value={newUser.name}
onChange={(e) => setNewUser({ ...newUser, name: e.target.value })}
className="mb-2 w-full p-2 border border-gray-300 rounded"
/>
<input
placeholder="Email"
value={newUser.email}
onChange={(e) => setNewUser({ ...newUser, email: e.target.value })}
className="mb-2 w-full p-2 border border-gray-300 rounded"
/>
<button type="submit" className="w-full p-2 text-white bg-blue-500 rounded hover:bg-blue-600">
Add User
</button>
</form>
{/* Form to update user */}
<form onSubmit={handleUpdateUser} className="mb-6 p-4 bg-blue-100 rounded shadow">
<input
placeholder="User Id"
value={updateUser.id}
onChange={(e) => setUpdateUser({ ...updateUser, id: e.target.value })}
className="mb-2 w-full p-2 border border-gray-300 rounded"
/>
<input
placeholder="New Name"
value={updateUser.name}
onChange={(e) => setUpdateUser({ ...updateUser, name: e.target.value })}
className="mb-2 w-full p-2 border border-gray-300 rounded"
/>
<input
placeholder="New Email"
value={updateUser.email}
onChange={(e) => setUpdateUser({ ...updateUser, email: e.target.value })}
className="mb-2 w-full p-2 border border-gray-300 rounded"
/>
<button type="submit" className="w-full p-2 text-white bg-green-500 rounded hover:bg-green-600">
Update User
</button>
</form>
{/* Display users */}
<div className="space-y-4">
{users.map((user) => (
<div key={user.id} className="flex items-center justify-between bg-white p-4 rounded-lg shadow">
<CardComponent card={user} />
<button onClick={() => deleteUser(user.id)} className={`${btnColor} text-white py-2 px-4 rounded`}>
Delete User
</button>
</div>
))}
</div>
</div>
);
};
export default UserInterface;
For an explanation, check: https://youtu.be/njNXTM6L0wc
Modify the index.tsx file
Opne the index.tsx
file and replace the content with the following:
import React from 'react';
import UserInterface from '../components/UserInterface';
const Home: React.FC = () => {
return (
<main className="flex flex-wrap justify-center items-start min-h-screen bg-gray-100">
<div className="m-4">
<UserInterface backendName="flask" />
</div>
</main>
);
};
export default Home;
For the explanation, check: https://youtu.be/njNXTM6L0wc
Add the Flask/Python logo
In the /frontend/public
folder, add the flasklogo.svg
file.
Refresh the page and you should see the flask logo.
đ§Ē Test the frontend
We are now ready to test the frontend.
You can use the UI to insert, update, and delete users.
You can create a user directly from the UI
You can check the updated users in the POsgres database
docker exec -it db psql -U postgres
select * from users;
You can also update a user
And finally, you can delete a user, just by clicking on the "Delete User' button
You can check the content of the database with the following command:
docker exec -it db psql -U postgres
select * from users;
Dockerize the frontend
Deploy a Next.js app with Docker.
Change the next.config.js
file in the frontend
folder, replacing it with the following content:
/** @type {import('next').NextConfig} */
const nextConfig = {
output: 'standalone',
};
module.exports = nextConfig;
Create a file called .dockerignore
in the frontend
folder and add the following content:
touch .dockerignore next.dockerfile
next.dockerfile
.dockerignore
node_modules
npm-debug.log
README.md
.next
.git
To dockerize the Next.js application, we will use the official Dockerfile provided by Vercel:
You can find it here: https://github.com/vercel/next.js/blob/canary/examples/with-docker/Dockerfile
Create a file called next.dockerfile
in the frontend
folder and add the following content (it's directly from the vercel official docker example)
FROM node:18-alpine AS base
# Install dependencies only when needed
FROM base AS deps
# Check https://github.com/nodejs/docker-node/tree/b4117f9333da4138b03a546ec926ef50a31506c3#nodealpine to understand why libc6-compat might be needed.
RUN apk add --no-cache libc6-compat
WORKDIR /app
# Install dependencies based on the preferred package manager
COPY package.json yarn.lock* package-lock.json* pnpm-lock.yaml* ./
RUN \
if [ -f yarn.lock ]; then yarn --frozen-lockfile; \
elif [ -f package-lock.json ]; then npm ci; \
elif [ -f pnpm-lock.yaml ]; then yarn global add pnpm && pnpm i --frozen-lockfile; \
else echo "Lockfile not found." && exit 1; \
fi
# Rebuild the source code only when needed
FROM base AS builder
WORKDIR /app
COPY --from=deps /app/node_modules ./node_modules
COPY . .
# Next.js collects completely anonymous telemetry data about general usage.
# Learn more here: https://nextjs.org/telemetry
# Uncomment the following line in case you want to disable telemetry during the build.
# ENV NEXT_TELEMETRY_DISABLED 1
RUN yarn build && ls -l /app/.next
# If using npm comment out above and use below instead
# RUN npm run build
# Production image, copy all the files and run next
FROM base AS runner
WORKDIR /app
ENV NODE_ENV production
# Uncomment the following line in case you want to disable telemetry during runtime.
# ENV NEXT_TELEMETRY_DISABLED 1
RUN addgroup --system --gid 1001 nodejs
RUN adduser --system --uid 1001 nextjs
COPY --from=builder /app/public ./public
# Set the correct permission for prerender cache
RUN mkdir .next
RUN chown nextjs:nodejs .next
# Automatically leverage output traces to reduce image size
# https://nextjs.org/docs/advanced-features/output-file-tracing
COPY --from=builder --chown=nextjs:nodejs /app/.next/standalone ./
COPY --from=builder --chown=nextjs:nodejs /app/.next/static ./.next/static
USER nextjs
EXPOSE 3000
ENV PORT 3000
# set hostname to localhost
ENV HOSTNAME "0.0.0.0"
# server.js is created by next build from the standalone output
# https://nextjs.org/docs/pages/api-reference/next-config-js/output
CMD ["node", "server.js"]
Now, let's update the compose.yaml
file in the project's root, adding the nextapp
service.
Below the updated version:
services:
nextapp:
container_name: nextapp
image: nextapp:1.0.0
build:
context: ./frontend
dockerfile: next.dockerfile
ports:
- "3000:3000"
environment:
- NEXT_PUBLIC_API_URL=http://localhost:4000
depends_on:
- flaskapp
# flask service
flaskapp:
container_name: flaskapp
image: flaskapp:1.0.0
build:
context: ./backend
dockerfile: flask.dockerfile
ports:
- '4000:4000'
restart: always
environment:
- DATABASE_URL=postgresql://postgres:postgres@db:5432/postgres
depends_on:
- db
# db service
db:
container_name: db
image: postgres:13
environment:
POSTGRES_USER: postgres
POSTGRES_PASSWORD: postgres
POSTGRES_DB: postgres
ports:
- 5432:5432
volumes:
- pgdata:/var/lib/postgresql/data
volumes:
pgdata: {}
And now, let's build the image and run the container:
docker compose build
docker compose up -d nextapp
You can check if the 3 containers are running:
docker ps -a
If you have the 3 services running, should be good to go.
Before we wrap up, let's make a final test using the UI.
đ§Ē Test the frontend
As a final test, we can check if the frontend is working.
To create a new user, add a name and email
We can check the list of users from the UI or directly from the database:
docker exec -it db psql -U postgres
\dt
select * from users;
đ Recap
We made it đ
We build a simple yet complete Python full-stack web app using:
- Next.js 14 (TypeScript)
- Tailwind CSS
- Flask (Python) + SQLAlchemy (ORM)
- PostgreSQL
- Docker
- Docker Compose
If you prefer a video version
All the code is available for free on GitHub (link in video description).
If you have any questions, comment below or in the video comments
You can find me here:
Francesco
Top comments (9)
Always used to read your article today I'm moderator it's an honor
Thank you Robina, highly appreciated! did you ever watch some video versions?
Yes, I also viewed the video, and initially, I thought it was someone else. Later, I realized it was you.
interesting! I try to be very consistent with thumbnails and style
yeah
Great stuff. Would also be interesting going into the deployment phase
thank you, for sure will do in an upcoming one
Amazing article and video as always!!đĨ
thank you !!