Docker vs Kubernetes

Containers and container management platforms provide a lot more advantages over traditional virtualization. Isolation is done on the kernel level without the need for a guest operating system, so containers are much more efficient, fast, and lightweight. Allowing for applications to become encapsulated in self-contained environments comes with a slew of advantages, such as quicker deployments, scalability, and closer parity between development environments.

With containers and container management platforms, applications can be scaled, load balanced and protected against failover almost automatically. Also, it allows for more than one application to be running the same server, maximizing server resource.

Kubernetes and Docker is a phrase that you hear more and more these days as Kubernetes becomes ever more popular as a container orchestration solution, and Docker as a standalone application which can be installed on any computer to run containerized applications.

Kubernetes and Docker are both comprehensive de-facto solutions to intelligently manage containerized applications and provide powerful capabilities, and from this, some confusion has emerged. Both are fundamentally different technologies but they work very well together, and both facilitate the management and deployment of containers in a distributed architecture.

Here, in this post, we explore the differences between these two platforms.

So, let's get started -

Docker

Docker is an open-source virtualization technology known as a containerization platform for software containers. These containers provide a means of enclosing an application, including its own filesystem, into a single, replicable package. It was first started in 2013 and is developed by Docker, Inc. The service has both free and premium tiers. The software that hosts the containers is called Docker Engine. Docker is a tool that can package an application and its dependencies in a virtual container that can run on any Linux server.

Kubernetes

Kubernetes is an open-source container management system developed by Google and made available to the public in June 2014. The goal is to make deploying and managing complex distributed systems easier for developers interested in Linux containers. It was designed by Google engineers experienced with writing applications that run in a cluster. It works with a range of container tools, including Docker. Many cloud services offer a Kubernetes-based platform or infrastructure as a service (PaaS or IaaS) on which Kubernetes can be deployed as a platform-providing service. Many vendors also provide their own branded Kubernetes distributions.

 

Kubernetes vs Docker

• Docker is a platform and tool for building, distributing and running Docker containers. It offers its own native clustering tool that can be used to orchestrate and schedule containers on machine clusters.

• Kubernetes is a container orchestration system for Docker containers that is more extensive than Docker Swarm and is meant to coordinate clusters of nodes at scale in production in an efficient manner.

• Docker implements a high-level API to provide lightweight containers that run processes in isolation.

• Kubernetes allows companies to harness more computing power when running software applications.

• Docker containers are lightweight, a single server or virtual machine can run several containers simultaneously.

• Kubernetes automates the deployment, scheduling, and operation of application containers on clusters of machines - often hundreds of thousands or more - in private, cloud or hybrid environments.

• Docker allows the deployment of nodes to be performed as the resources become available or when more nodes are needed, allowing a platform as a service (PaaS)-style of deployment and scaling for systems such as Apache Cassandra, MongoDB, and Riak.

• Kubernetes also allows developers to create a “container-centric” environment with container images deployed on Kubernetes or integrate with a continuous integration (CI) system.

• Docker is a tool that is designed to benefit both developers and system administrators, making it a part of many DevOps (developers + operations) toolchains.

• Kubernetes container management system allows enterprises to create an automated, virtual, microservices application platform.

• Docker gives flexibility and potentially reduces the number of systems needed because of its small footprint and lower overhead.

• Kubernetes automates the process of scaling, managing, updating and removing containers. In other words, it is a container orchestration platform. While Docker is at the heart of containerization, it enables us to have containers in the first place.

• Docker brings security to applications running in a shared environment, but containers by themselves are not an alternative to taking proper security measures.

• One can easily run a Docker build on a Kubernetes cluster, but Kubernetes itself is not a complete solution and is meant to include custom plugins.

• Kubernetes provides a virtual platform for applications to run on with OS resources called via a REST API. It is a form of microservices architecture using portable executable images that contain software and all of its dependencies.

• Docker can be installed on any OS, even Windows and Mac OS X are well-supported. So you can package your code into a Docker image, run and test it locally using Docker to guarantee that the containers that were created from that Docker image will behave the same way in production.

• Kubernetes can work with any containerization technology. Two of the most popular options that Kubernetes can integrate with are rkt and Docker.

• Docker has won the greatest market segment and that has led to a lot of effort in perfecting the integration between Docker and Kubernetes, more than any other containerization technology.

• Kubernetes specifies that each pod should be able to freely communicate with every other pod in the Cluster, in a given namespace. Whereas Docker has a concept of creating virtual network topologies and you have to specify which networks you want your containers to connect to.

• It requires a series of manual steps to setup Kubernetes Master and worker nodes components in a cluster of nodes

• Installing Docker is a matter of one-liner command on Linux Platform like Debian, Ubuntu, and CentOS.

• Kubernetes provides no native storage solution for log data, but you can integrate many existing logging solutions into your Kubernetes cluster. Few of popular logging tools are listed below:

• Logging driver plugins are available in Docker. Logging capabilities available in Docker are exposed in the form of drivers, which is very handy since one gets to choose how and where log messages should be shipped.

• Kubernetes can do auto-scaling, but Docker Swarm cannot do auto-scaling.

• Kubernetes can deploy Rolling updates & does automatic Rollbacks. Docker Swarm can deploy Rolling updates, but not automatic Rollbacks.

• Kubernetes is more of an all-in-one framework. It is a complex system because it provides strong guarantees about the cluster state and a unified set of APIs.

• Docker Swarm, when compared to Kubernetes, can deploy container much faster and this allows faster reaction times to scale on demand.