In this post, I will be showing you how I deployed a Flask app on an AWS Ubuntu Server 16.04 LTS server using nginx and Gunicorn. Gunicorn is a server that will be running our app and nginx will be used as our reverse-proxy server.

Server Setup

Before we get started, we will need to have an Ubuntu instance running with port 80 opened up to the public. A non-root user will need to be added with sudo privileges. I will not be going over how to set this up in this post. You can still continue running everything as the root user, but it is not recommended.

nginx Installation and Setup

First, we will install nginx.

$ sudo apt-get update
$ sudo apt-get install nginx

Once nginx is installed, you should be able to go to your public IP or public DNS and see the nginx welcome page.


We will remove the default page by deleting the default file.

$ sudo rm /etc/nginx/sites-enabled/default

We will create a new config file in the sites-available folder and create a symbolic link to it in the sites-enabled folder.

$ sudo vim /etc/nginx/sites-available/

This is how the config file will look:

server {
	listen 80;

	location / {

This config file will tell the nginx server to listen on port 80 and pass all requests with the ‘/’ prefix to the server We do this because Gunicorn will run your Flask app on port 8000.

Now, we will need to create a symbolic link from the sites-enabled directory that points to the config file we created.

$ sudo ln -s /etc/nginx/sites-available/ /etc/nginx/sites-enabled/

We will need to restart our nginx web server in order for our changes to take into effect.

$ sudo service nginx restart

Create Simple Flask App

We will install the venv library for Python 3. Python 2 can be used but in this example, we will be using Python 3.

$ sudo apt-get install python3-venv

We will create a directory for our app and create a virtual environment.

#we will be creating the directory in our home directory
$ cd ~
$ sudo mkdir example
$ cd example
$ sudo python -m venv example_env

This will create the example_env directory with all the files for our virtual environment.

Before we set up our Flask app, we will have to activate our virtual enviornment and install the necessary libraries.

$ source example_env/bin/activate

One you activate the virtual environment, you should see the name of your virtual environment in parentheses to the left of your shell prompt. Next, we will install the libraries needed to create and run our Flask app.

(example_env) $ pip install flask gunicorn

Once we have our libraries installed, we can create our Flask app.

(example_env) $ sudo vim

For our app, we will create a simple hello world example.

from flask import Flask

app = Flask(__name__)

def hello_world():
	return 'Hello World!'

if __name__ == "__main__":

Run the App with Gunicorn

We will now run the Flask app with Gunicorn.

(example_env) $ gunicorn helloworld:app

Gunicorn should have started and should be listening at

If you go back to the public IP or public DNS of your server, you should be able to see that our app is running.


We now have a running Flask app on our Ubuntu EC2 Instance using nginx and Gunicorn :smiley: