You created a simple Flask application and set up logging. Now, you're going to take the next step and package this application into a Docker image.

Why do this? Packaging the app into a Docker image allows you to run it consistently on any machine, without worrying about missing dependencies or differences in the environment. This makes testing, deployment, and sharing your app much easier and more reliable.

Creating the Project Folder

First, you need a dedicated folder to store all your configuration and application files. Open your terminal and run the following command:

This command creates a folder called elk-demo and immediately navigates into it.

Next, you'll create the Flask application file:

Paste the code from the previous chapter into this file.

Now you have a complete Flask application ready to be packaged into a Docker container.

Creating the Dockerfile

Next, you'll create a Dockerfile. The Dockerfile defines how to package your application into an image. In the terminal, run:

Paste the following code into the Dockerfile:

You start from a lightweight Python 3.10 image, which gives you a minimal environment with Python installed. Then you set a working folder inside the container for your app. The Flask application file is copied into this folder, and Flask is installed so the app can run. The container is set up to allow access on port 5000, and finally, when the container starts, it automatically runs your Flask application.

At this point, your app is fully prepared. With this Dockerfile, you can now build a Docker image and run it anywhere, ensuring it works consistently across different machines.