Kubernetes vs Docker

As open source leaders in container technologies, Kubernetes and Docker stand out. There is a misconception that many people have to do with which option to choose. In reality, they are fundamentally different technologies and do not compete — it is not an either/or scenario. In addition to excelling in their respective fields, they provide complementary strengths that are powerful when combined.

The goal of this post is to introduce the fundamentals of Kubernetes and Docker and explore the advantages of using them individually and together. In order to do so, we need to focus on the technology that ties them together: containers.

What is a Container?

Containers are often referred to as Docker, but the reality is that they have been around long before Docker. Since the introduction of chroot in the late 1970s, Linux and Unix have had containers in some form or another. Administrators were able to run programs in a kind-but-not-really-isolated filesystem using Chroot. Over the years, this idea has evolved into container engines like FreeBSD Jails, OpenVZ, and Linux Containers (LXC).But what are containers?

An application container is a logical partition in which applications can run independently of the rest of the system. The host and other containers do not share any of the virtual filesystems or networks of the applications.

Containers, It is much easier to run containerized applications than to install and configure the software. One advantage of containers is that they can be built in one server with the confidence that they will work in any server. We also have the advantage of running multiple copies of the same program simultaneously, something very difficult to do otherwise.

To make all of this work, we need a container runtime, a piece of software that can run containers.

What is Docker?

Docker is an open-source platform for containerization. Developers can use it to build, deploy, and manage containers in a safer, faster, and easier way. Despite first appearing as an open-source project, Docker is also the name of a commercial product produced by Docker, Inc. Currently, it’s the most popular tool to create containers on Windows, Linux, and macOS.

Despite Docker’s release in 2013, container technologies have been around for decades. Linux Containers (or LXC) were the most popular early on. Originally based on LXC, Docker’s customized technology quickly became more popular than LXC.

Docker’s portability is one of its key features. Containers running on Docker can run across desktops, data centers, or clouds. One process can run in each container, so an application can continue running while undergoing an update or repair.

The following are a few of the tools and terms commonly used with Docker:

· Docker Engine : A runtime environment for building and running containers.

· Dockerfile: This is a simple text file that contains details such as network specifications and file locations for building Docker containers. There is essentially a set of commands that Docker Engine will run to build the image.

· Docker Compose: is an application that enables multi-container development and deployment. It creates a YAML file specifying which services will be available in the application and can run containers with just one command via the Docker command-line interface.

Other Docker API features include automatic tracking and rolling back of container images, using existing containers as base images for creating new ones, and building containers based on application source code. Thousands of containers are shared via the Docker Hub by a vibrant developer community.

What is Kubernetes?

Kubernetes is an open-source system for managing and orchestrating containerized applications through automated deployment, management, and scalability. The Kubernetes cluster is a collection of multiple containers running in parallel. A master node is responsible for scheduling workloads for the other containers in the cluster, or “worker nodes.”

Basically, the master node determines where to host applications (or Docker containers), how to assemble them, and how to orchestrate them. In addition to facilitating discovery and managing high volumes of containers throughout their lifecycles, Kubernetes consolidates the containers that comprise an application into clusters.

Kubernetes was introduced by Google as an open-source project in 2014. Currently, it is managed by the Cloud Native Computing Foundation, an open-source software foundation. Due to its robust functionality, an active open-source community of thousands of contributors, and portability across leading public cloud providers (e.g., IBM Cloud, Google, Azure, and AWS), Kubernetes is a popular container orchestration system.

The major functions of Kubernetes include the following:

· Deployment: Schedules and automates the deployment of containers across multiple instances, such as VMs and bare-metal servers.

· Service discovery and load balancing: Uses load balancing to maintain efficiency when traffic spikes occur.

· Auto-scaling features: Using CPU utilization, memory thresholds, or custom metrics, adds new containers as needed to handle heavy loads.

· Self-healing capabilities: Easily starts, replaces, rescheduled, and kills containers according to user-defined health checks.

· Automated rollouts and rollbacks: Roll out changes to an application, monitor its health for any issues, and roll back changes if something goes wrong.

· Storage orchestration: Add persistent storage to the local system or to the cloud automatically for reduced latency.

Kubernetes and Docker: Finding your best container solution

Docker and Kubernetes are distinct technologies, but their complementary nature makes them an incredibly powerful combination. The containerization piece is provided by Docker, allowing developers to package and isolate applications with a single command. Application developers are then able to run those applications on their IT environment with no worry of compatibility issues. During testing, an application will run anywhere if it runs on a single node.

With Kubernetes, the orchestration of Docker containers is automated, ensuring high availability during periods of high demand. Furthermore, Kubernetes offers load balancing, self-recovery, and automated rollouts and rollbacks in addition to running containers. The interface is graphical to make it easy to use.

Kubernetes might be a good choice for companies that plan on scaling their infrastructure in the future. If you’re already using Docker, Kubernetes uses your existing containers and workloads, while handling the complexity of moving to scale.

Conclusion

Although the growth of Kubernetes is not a traumatic experience, it does need to be considered. The majority of users will not have to take any action. There is still time to test and plan for those who have done so.