In this article, we will show you how to install and use Flask on a Fedora system.

Prerequisites

Before you start, make sure that you have the following installed on your system:

• Python 3: Flask is a Python web framework, so you will need to have Python installed on your system. You can check if you have Python installed by running the following command:

  python3 -V 
  

  If Python is not installed, you can install it by running the following command:

  sudo dnf install python3 
  

• Pip: pip is the package manager for Python. It is used to install Python packages, such as Flask. You can check if you have pip installed by running the following command:

  pip3 -V 
  

  If pip is not installed, you can install it by running the following command:

  sudo dnf install python3-pip 
  

Installing Flask on Fedora

Once you have Python and pip installed, you can use pip to install Flask. To install Flask, run the following command:

pip3 install Flask 

This will install Flask and all of its dependencies.

Creating a Flask App

Now that you have Flask installed, you can create a simple Flask app. Create a file called app.py and add the following code:

from flask import Flask

app = Flask(__name__)

@app.route('/')
def hello():
    return 'Hello, World!'

if __name__ == '__main__':
    app.run()

This code creates a simple Flask app that displays a message when you visit the root URL.

Run Your Flask Application

To run the Flask app, open a terminal and navigate to the directory where you saved app.py. Then, run the following command:

python3 app.py 

This will start the Flask development server, and you should see the following output:

Output
 * Serving Flask app 'app'
 * Debug mode: off
WARNING: This is a development server. Do not use it in a production deployment. Use a production WSGI server instead.
 * Running on http://127.0.0.1:5000
Press CTRL+C to quit

To view the app, open a web browser and go to the URL http://127.0.0.1:5000/. You should see the message “Hello, World!” displayed on the page.

Conclusion

In this article, we showed you how to install and use Flask on a Fedora system. Flask is a lightweight and easy-to-use web framework that is perfect for developing small web applications. With Flask, you can create powerful and dynamic web applications with minimal effort.

The post How to Install and Use Flask in Fedora 37/36 appeared first on TecAdmin.

In this tutorial, we will show you how to install Flask on Debian 11. Debian 11, also known as “Bullseye,” is the latest stable release of the Debian operating system. It is a free and open-source operating system that is widely used on servers and other systems.

Prerequisites

Before you start, make sure that you have Python and pip installed on your system. You can check if you have Python installed by running the following command:

python3 --version 

If you do not have Python installed, you can install it by running the following command:

sudo apt update 
sudo apt install python3 python3-pip python3-venv 

To check if you have pip installed, run the following command:

python3 --version 
pip3 --version 

Step 1: Installing Flask

Once you have Python and pip installed, you can install Flask system-wide by running the following command: `pip3 install flask`

But I recommended creating a virtual environment for your Flask application.

1. Create a directory for your Flask application:

   mkdir flask-app && cd flask-app 
   

2. Create the Python virtual environment.

   python3 -m venv venv 
   

3. Activate the virtual environment:

   source venv/bin/activate 
   

4. Install the Python Flask module within the virtual environment.

   pip3 install flask 
   

This will install the latest version of Flask and all the required dependencies under the virtual environment.

Step 2: Creating a Flask Application

Now that Flask is installed, you can create your first Flask application. Switch to the newly created application directory:

cd flask-app 

Next, create a file called `app.py` and add the following code to it:

from flask import Flask

app = Flask(__name__)

@app.route('/')
def hello():
    return 'Hello, World!'

if __name__ == '__main__':
    app.run()

This code creates a simple Flask app that listens for incoming HTTP requests on the root path (/) and returns the message “Hello, World!”.

Step 3: Run Your Flask Application

To run the application, execute the following command:

flask run 

This will start the Flask development server and you will see the following output:

Output:
 * Serving Flask app "app"
 * Environment: production
   WARNING: This is a development server. Do not use it in a production deployment.
   Use a production WSGI server instead.
 * Debug mode: off
 * Running on http://127.0.0.1:5000/ (Press CTRL+C to quit)

Now, open your web browser and go to “http://127.0.0.1:5000/” to view your Flask app. You should see the message “Hello, World!” displayed on the page.

Conclusion

In this tutorial, you learned how to install and use Flask on Debian 11. You also learned how to create a simple Flask app and run it using the Flask development server. Flask is a powerful and easy-to-use web framework that makes it easy to build web applications with Python.

The post How to Install and Use Flask on Debian 11/10 appeared first on TecAdmin.

Flask is easy to get started with and doesn’t require any particular directory structure. A Flask application is a Python script that imports the Flask module creates an instance of the Flask class, and then start the development server using a line of code.

In this article, we’ll show you how to install Flask on Ubuntu 22.04. Also, create a simple Hello World application using the Flask Python module.

Step 1: Installing Python

Before you start, make sure you have Python and pip installed on your system. If you don’t have them already, you can install them by running the following commands:

sudo apt update 
sudo apt install python3 python3-pip python3-venv 

Step 2: Install Flask on Ubuntu

Once Python and pip are installed, you’re ready to install Flask. To do this, you’ll need to open a terminal and enter the following command: `pip3 install Flask`

But we recommend creating Python virtual environment to isolate your application. To do this create and/or switch to your flask application directory:

mkdir flask-app && cd flask-app 

Now, create and activate the virtual environment:

python3 -m venv venv
source venv/bin/activate

The above commands will create a directory with the name “venv” for storing virtual environment files. The second command will activate it. The system command prompt will be modified with the virtual environment name.

Once the virtual environment is activated, you can install Flask and other required Python modules.

pip3 install Flask 

This will install the latest version of Flask and all its dependencies. Once the installation is complete, you can verify that Flask is installed correctly by running the following command:

python3 -m flask --version 

If everything is working correctly, you should see the version number of Flask printed on the terminal.

Step 3: Create a Sample Flask Application

Once Flask is installed, you can start building your web application. To do this, create a new Python script and import the Flask module. Then, create a new Flask app using the following code:

from flask import Flask

app = Flask(__name__)

@app.route('/')
def hello():
    return 'Hello, World!'

if __name__ == '__main__':
    app.run()

This code creates a simple Flask app that listens for requests at the root URL and returns the message “Hello, World!”. You can run this script by entering the following command:

python3 app.py 

This will start the Flask development server and listen for requests on port 5000. To access your application, open

Step 4: Finishing Your Work

You can create the `requirements.txt` file which is helpful for deploying applications on other systems. This file contains the Python modules required for your application.

pip freeze > requirements.txt

Once you finish your work with this project, You can simply deactivate the virtual environment by running the following command:

deactivate

Conclusion

In conclusion, installing Flask on Ubuntu 22.04 is a straightforward process that involves installing Python and pip, and then using pip to install Flask. Once Flask is installed, you can start building your web application by creating a new Python script and importing the Flask module. Then, create a new Flask app and start the development server using a line of code.

Flask is a lightweight and flexible web framework that is easy to get started with and doesn’t require any particular directory structure. It’s a good choice for small projects and prototyping, and it can be extended with a variety of third-party libraries to add additional functionality. With Flask installed, you’re now ready to start building your web applications on Ubuntu 22.04.

The post How to Install and Use Flask on Ubuntu 22.04 appeared first on TecAdmin.

In this process, you’ll also learn how to use multiple Python virtual environments and keep your source code organized. If you’re new to Python or Flask, you may want to check out our beginner guide to Python as well as our beginner guide to Flask first. They cover the basics of these frameworks so that you can follow along better in this tutorial. Let’s get started!

What is Flask?

Flask is a lightweight Python framework for building web applications. It is simple, flexible, and pragmatic. It can be easily extended with the use of extensions and plug-ins. Flask can be used to create small websites or large-scale, complex applications.

Flask is used by companies like Pinterest, Twitter, Walmart, and Cisco. One of the common uses of Flask is for REST APIs that are used to interact with other systems. Applications written in Flask can also easily be deployed to a server or a cloud.

Create a Basic Flask Application

Before you can create a Docker image with your application, you have to have a basic app that you can run locally or on a server.

In this section, you will create a basic app with Flask and then run it in a Docker container. You can use your preferred editor to create the app, or you can use the following command in your terminal to create a new app:

1. Let’s begin with creating a new directory:

   mkdir flask-app && flask-app 
   

2. Next, create the Python virtual environment and then activate the environment.

   python3 -m venv venv 
   source venv/bin/activate 
   

3. Now install the Flask python module under the virtual environment.

   pip install Flask 
   

4. The below command will create the requirements.txt file with the installed packages under the current environment. This file is useful for installing module at deployments.

   pip freeze > requirements.txt 
   

5. Now, create a sample Flask application.. You can write your code in a .py file and run it with the python command.

   vim app.py 
   

   Add the below snippt.

   # Import flask module
   from flask import Flask
   
   app = Flask(__name__)
   
   @app.route('/')
   def index():
       return 'Hello to Flask!'
   
   # main driver function
   if __name__ == "__main__":
       app.run()

6. Your sample Flask application is ready. You can run this script with Python now.

   flask run --host 0.0.0.0 --port 5000 
   

   

Now that you have a basic app, you can run it in a Docker container by creating a file called Dockerfile in the same directory as your app.py file.

Create a Dockerfile for Your Flask Application

A Dockerfile is a file that contains instructions on how to build your image. It describes the entire process of building your image from the installation of your Python app to the creation of your container.

1. Let’s create a file named Dockerfile under the project directory. This is the file docker reads instructions to build image.

   vim Dockerfile 
   

   Add the following code:

   FROM python:3-alpine
   
   # Create app directory
   WORKDIR /app
   
   # Install app dependencies
   COPY requirements.txt ./
   
   RUN pip install -r requirements.txt
   
   # Bundle app source
   COPY . .
   
   EXPOSE 5000
   CMD [ "flask", "run","--host","0.0.0.0","--port","5000"]
   

   Save the file and close it.

2. Next, create the Docker image by running the below-mentioned command. Here “flask-app” is the image name.

   docker build -t flask-app . 
   

3. This image will be created in local image registry. Then you can create a Docker container with the following command.

   sudo docker run -it -p 5000:5000 -d flask-app  
   

4. Now, verify that container is running on your system.

   docker containers ls  
   

   

5. Finally, open a browser and connect to localhost on port 5000 (or use your own defined port). You should see the flask application.

   

You can use a Dockerfile to automate the building and updating of your image. This is helpful if you’re working with a team and people are adding code to the same application.

Conclusion

In this tutorial, you learned how to create a basic Flask app and build a Docker image with it. You also learned how to create a private registry and automate the building and updating of your image. This is a great way to create reproducible builds and container images that are easy to share and deploy. This can be helpful if you need to set up servers or if you want to run your app on different machines.

The post How to Dockerize a Flask Application appeared first on TecAdmin.