Docker vs Kubernetes

As mobile network engineers, we are often well-versed in radio, 4G, and 5G technologies, yet many of us feel a bit distant when the conversation turns to IT development tools. I count myself among them, being a beginner in IT and programming. However, after trying Docker for workflow automation using n8n and setting up web development environments, the similarities and differences with Kubernetes began to surface. While Kubernetes is widely used in 5G Core Network and Cloud RAN deployments, I have summarized the differences and insights I discovered from an IT development environment perspective.

Below, I will briefly explain the Docker architecture, compare it with Kubernetes, and highlight the benefits of Kubernetes in a way that is easy to understand. This guide is targeted at telecom industry engineers who may not yet be deeply familiar with IT development environments.

First, Docker Basics: How does it work?

If we think in terms of mobile network construction, we need reliable components that work regardless of the environment. Docker is an open-source platform that packages applications and their dependencies into lightweight, independent "containers." Since containers run identically on laptops, servers, or the cloud, they significantly reduce troubleshooting during testing and deployment.

The main components of Docker are as follows:

• Docker Engine: The center of the system, corresponding to the core network in telecom. A background daemon handles the creation, execution, and monitoring of containers. It is operated by entering commands via the Docker CLI.
• Images: Think of these as blueprints for an application. They are read-only templates containing code, runtime, libraries, and settings. You can download them from Docker Hub or build your own using a Dockerfile. It is similar to creating scripts for network configuration.
• Containers: These are the executed instances of images. While similar to Virtual Machines (VMs), they are lightweight and start faster because they share the host OS kernel. Each container is isolated from the others, allowing multiple apps to run on a single machine without interference.
• Docker Compose: A tool useful for complex setups. You define a multi-container application in a YAML file and launch the entire environment with a single command. It is very convenient for n8n projects or web development stacks.

In short, Docker is a tool suited for single-node environments. It has the simplicity akin to managing a standalone gNodeB, making it suitable for personal projects or small-scale use cases. On the other hand, if you require cluster management like a nationwide 5G network, Kubernetes is the appropriate choice.

Docker vs. Kubernetes: Similarities and Differences

Since both Docker and Kubernetes (K8s) deal with containers, they are complementary rather than rivals. Kubernetes uses Docker (or compatible runtimes) to execute containers. While Docker excels at basic management on a single machine, Kubernetes is an enterprise tool designed to orchestrate clusters across multiple machines.

Here is a brief summary of the comparison:

• Scale: Docker is for single hosts, similar to operating a standalone cell site. Kubernetes supports clusters, automatically distributing workloads like a distributed RAN to improve performance and reliability.
• Management & Automation: Docker involves manual start, stop, and linking operations (though Compose helps). Kubernetes features declarative management (YAML) to automate scaling and updates, similar to setting QoS policies.
• Networking & Storage: Docker provides basic networking within the host. Kubernetes handles advanced networking and service discovery (equivalent to telecom DNS), as well as volumes where data persists even after container restarts.
• Deployment & Updates: Docker is simple but manual. Kubernetes supports rolling updates and canary deployments, minimizing downtime—ideal for telecom's always-on requirements.

For reference, the detailed comparison by function is summarized in the table below.

As a common point, since the container format is the same, Docker skills are easily transferable to Kubernetes. The core difference lies in orchestration: if Docker is the engine, Kubernetes plays the role of the conductor.

Why Telecom Engineers Choose Kubernetes: Key Benefits

After actually using both, the transition from Docker to Kubernetes feels natural. Especially in telecom, where downtime leads to service interruption, the strengths of Kubernetes stand out. The major benefits are as follows:

• Cluster vs Single Node: Docker is convenient for a single machine, but it has limitations for large-scale deployments like Cloud RAN. Kubernetes clusters servers to pool resources and automate load balancing. This is similar to the evolution from a single base station to C-RAN (Centralized RAN).
• High Availability (HA): With Docker, if the host goes down, the app stops. Kubernetes distributes replicas across nodes; if one fails, others take over. Like redundant paths in a transport network, it maintains 99.999% availability.
• Continuous Reconciliation and Self-Healing: It constantly checks the actual state against the desired state and corrects any differences. It restarts crashed containers and reschedules workloads on loaded nodes. This is similar to automated fault management in NMS, saving manual effort.
• Accelerating DevOps with GitOps Integration: Combining Kubernetes and GitOps in Cloud RAN allows you to manage infrastructure as code. Version control with Git and automated application via ArgoCD reduces manual errors and speeds up OSS updates.

These features resolve the complexity of distributed workloads, offering value that exceeds the limits of Docker in a production environment.

Summary: Let's Start Using Containers in the Field

If you are a telecom engineer looking to understand Kubernetes more deeply, I recommend starting by trying out small-scale projects using Docker. It allows you to learn the basics easily and deepens your understanding of Kubernetes orchestration. You might also want to try Kubernetes on a small cluster (such as Minikube). Doing so will surely expand the utilization of containers in the telecom field.