A Beginner's Guide to Docker on IoT Edge Gateways

So, you're looking to deploy an application on an   Industrial IoT Edge Gateway  . You have your code, but now you're facing a common headache: how do you ensure your application runs the same way on the gateway as it did on your development machine? How do you manage all its dependencies without creating conflicts?

For years, engineers have wrestled with this "it works on my machine" problem. This is where Docker comes in.  Docker  is a platform that packages your application and all its dependencies—libraries, code, and runtime—into a single, portable unit called a  container . Think of it as a lightweight, self-contained box that can run anywhere, from your laptop to a powerful industrial gateway like the   Robustel EG5120  . This guide will show you just how easy it is to get started with  Docker on IoT Edge Gateways .

Before we dive into the "how-to," let's look at the hardware. To properly run  Docker on IoT Edge Gateways , you need a device with enough processing power and a modern OS. The Robustel EG5120 is an industrial-grade edge computing gateway built for these kinds of containerized workloads.

Key EG5120 Specifications:

• Processor: Quad-core 1.6 GHz Cortex-A53 CPU
• NPU: 2.3 TOPS for machine learning inference
• Memory & Storage: 2 GB DDR4 RAM, 16 GB eMMC Flash
• Connectivity: 2 x Ethernet, 2 x RS232/RS485, 2 x DI/DO, optional Wi-Fi, Bluetooth, GPS/GNSS
• Operating System: RobustOS Pro (Debian 11-based), supports Docker

This robust hardware provides a stable and powerful foundation for running your containerized applications reliably in the field.

So, why go to the trouble of containerizing your app? I've seen teams accelerate their deployment schedules by weeks by adopting this approach. Here are the core benefits:

• Portability:  A container built on your laptop will run identically on the EG5120. This "build once, run anywhere" philosophy eliminates compatibility headaches.
• Isolation:  Each container runs in its own isolated environment. This boosts security and prevents different applications from conflicting with each other over shared libraries.
• Efficiency:  Containers share the host gateway's OS kernel, making them incredibly lightweight and fast compared to traditional virtual machines. This is crucial for resource-constrained edge devices.
• Scalability & Rapid Deployment:  Once you have your container image, you can deploy hundreds or thousands of instances across your fleet of gateways effortlessly.

These perks make  Docker on IoT Edge Gateways  a true game-changer for modern IoT.

Before starting, ensure you have:

• Access to the EG5120 router via SSH.
• Internet connectivity via Ethernet or a 4G SIM card.
• Basic Linux knowledge for terminal commands.

Before we start, we need to create sudo privileges directly through the web UI. Follow the steps below:

Navigate to the User Management Section Go to: Sudo user > Sudo User Settings Click on "Add" to create a new user.

Configure User Settings Fill in the required fields. (PS: Enter the old password for the sudo account. This option will be displayed when you need to change the sudo password.)

For  Docker on IoT Edge Gateways  running a Debian-based OS like RobustOS Pro, the easiest method is to use Docker's official convenience script.

1. Log in via SSH and Create a Sudo User:  First, log into the EG5120's web interface, create a sudouser for command-line access, and then use an SSH tool to log in.
2. Download the Convenience Script:

Bash

3. Run the Script to Install Docker:

Bash

4. Add Your User to the Docker Group (Optional):  This allows you to run Docker commands without sudo. You'll need to log out and log back in for this to take effect.

Bash

5. Verify Installation:  Run the classic test container to confirm Docker is working correctly.

Bash

You should see a "Hello from Docker!" message.

Let's try a simple, practical example to see the power of  Docker on IoT Edge Gateways . We'll run an Nginx web server.

1. Pull the Nginx Image:  This command downloads the official Nginx image from Docker Hub.

Bash

2. Run the Nginx Container:  This command starts the web server and maps the gateway's port 80 to the container's port 80.

Bash

3. Check Container Status:

Bash

4. Access the Web Server:  Open a browser and navigate to http://. You should see the Nginx welcome page!

This simple example demonstrates how easily you can deploy complex applications. You can replace Nginx with IoT-specific containers, like an MQTT broker or a Node-RED instance.

Learning to use Docker on IoT Edge Gateways is a powerful skill that transforms how you deploy and manage applications. It moves you from manual, device-by-device setup to an automated, scalable, and reliable workflow. With a powerful device like the Robustel EG5120, which supports Docker on its Debian-based OS, you have a professional platform to build and scale your industrial IoT solutions with confidence.