Demystifying the Flow: Understanding How React, Express, NGINX, and Docker Work Together
Tags: webdev, beginners, javascript, react
Published: 2023-09-25 18:43:29


In the ever-evolving realm of web development, the process of creating applications has evolved into a captivating and interconnected journey. Have you ever felt like you're navigating a web development maze armed with an incomplete map?

Let's dive into this intriguing journey, one that frequently involves a stack boasting React, Express, NGINX, and Docker. It promises an exhilarating challenge for budding software engineers. But beneath the surface of this adventure lies a puzzle that can appear quite complex, especially to those new to web development.

###Navigating the Maze

I recently embarked on this very journey while developing [my first web app](https://github.com/kleinaitis/gridspace-admin-plus) using these technologies.  It quickly became apparent that the diagrams and resources available often portray only part of the story, leaving us with a one-sided map that shows information flowing downstream, like this illustration:
![Diagram illustrating the one-sided flow of data from the client to NGINX and beyond, focusing on downstream interactions](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/6n4mva8pmx1oy6m4kblk.png)

###Demystifying the Journey
In this article, we're going to demystify the web application flow step by step, guiding you through the intricate dance of React, Express, NGINX, and Docker. My goal here is to provide newer users with a crystal-clear understanding of how these technologies interact within the interconnected web application ecosystem.

Here is a more comprehensive view of the web application flow, including the journey back:
![Diagram illustrating the comprehensive bidirectional flow of data from the client to NGINX and beyond, emphasizing interactions in both directions.](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/jfkc9jhkkwmc2gmy64j7.png)

While this chart doesn't include all the details, here's a written version that offers a more comprehensive view:

1. **User Accesses the Site:** It all begins when a user accesses your web application.
2. **Request Reaches the Reverse Proxy (NGINX):** The user's request hits the reverse proxy server, which is NGINX in our case. NGINX acts as the gatekeeper, directing traffic to the appropriate destination.
3. **NGINX Routes to the Frontend ("/"):** NGINX routes the request to the frontend of your application, typically handling routes like the root path ("/").
4. **Frontend Generates and Sends HTML/JS to NGINX:** The frontend generates the HTML and JavaScript required for the user interface and sends it back to NGINX.
5.** NGINX Serves Content to the User:** NGINX serves this content to the user's browser, allowing them to interact with the frontend.
6. **User Interacts with the Frontend:** The user interacts with the frontend, making requests for various resources or data. 
7. **Requests to the Backend:** When a user makes a request that requires data from the backend (e.g., "/api/example"), it goes through the reverse proxy again.
8. **NGINX Routes to the Backend (Express):** NGINX directs the request to the backend, which is typically powered by Express.js.
9. **Backend Makes a GET Request to a Third-Party API:** The backend, now handling the request, might need to fetch data from a third-party API. It does so by making a GET request.
10. **Third-Party API Responds with JSON:** The third-party API responds with JSON data containing the requested information.
11. **Backend Routes JSON Response to NGINX:** The backend routes the JSON response back to NGINX.
12. **NGINX Serves the Response to the User's Browser:** Finally, NGINX serves the JSON response to the user's browser, completing the journey of data.

###Unlocking the Power of Docker and NGINX
This comprehensive understanding of web application architecture is not just enlightening; it's essential, especially for those new to the field. It unveils how Docker and NGINX are intricately woven into the fabric of modern web development, highlighting their pivotal roles in crafting robust and scalable applications.

Docker and NGINX are powerful tools that can significantly enhance the performance, security, and scalability of your web applications. By understanding how these technologies work and how to use them effectively, you can build more reliable and user-friendly applications capable of meeting the demands of even the most discerning users.

###Join My Journey
I hope this article has successfully demystified the web application flow and provided you with a deeper understanding of Docker and NGINX's pivotal roles in modern web development. If you have any questions or insights to share, please feel free to leave a comment below. Your feedback is invaluable!

Additionally, if you found this article informative and would like to explore more about web development and related technologies, I invite you to connect with me via my social profiles:

LinkedIn: [Connect with me on LinkedIn](https://www.linkedin.com/in/kleinaitis/)
GitHub: [Visit my GitHub profile](https://github.com/kleinaitis)

Thank you for joining me on this journey through the intricacies of web development. Stay curious, keep coding, and let's continue exploring the dynamic world of technology together!