Understanding the Guestbook application

Since the second part of this book will be centered around developing a Helm chart to deploy the Guestbook application, let’s first understand what this application does and what its architecture looks like.

The Guestbook application is a simple PHP: Hypertext Preprocessor (PHP) frontend designed to persist messages to a Redis backend. The frontend consists of a dialog box and a Submit button, as illustrated in the following screenshot:

Figure 4.1 – The Guestbook PHP frontend

To interact with this application, users can follow these steps:

1. Type a message in the Messages dialog box.
2. Click the Submit button.
3. When the Submit button is clicked, the message will be saved to the Redis database and displayed at the bottom of the page, as shown in the following screenshot:

Figure 4.2 – The Guestbook frontend after a new message has been submitted

Redis is an...