Keeping up with new technologies is more critical than ever for companies, which means that DevOps Engineers are highly sought afterāand well-compensated. According to ZipRecruiter, the average salary for a DevOps Engineer in the U.S. is more than $130,000 a year, with some DevOps specialists earning up to $178,000.Ā
For DevOps Engineers, keeping up with all the tools surrounding new technologies is more important than ever. Two essential tools these days are Kubernetes and Docker, which are used to get the software to run reliably when it needs to be moved from one computing environment to anotherāsay, from a testing environment into an actual production environment, or an on-premises computer to the cloud. These environments might not be the same, which can cause issues in how the software runs. Thatās where containers, and Kubernetes and Docker, come in, and in this article, we will understand the difference between Kubernetes and Docker.
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What is a Container?
A container encompasses an entire runtime environment. Itās a bundle that includes not the application but the associated dependencies, libraries, and other configuration files. Containerization is an evolution of virtualization, and containers have several advantages over virtual machinesāfor example, they are more efficient, using far fewer resources than virtual machines. Theyāre also lightweight, so one server can host many more containers than virtual machines.
If youāre in the field of information technology and considering container platforms (and who isnāt these days?), youāll undoubtedly come across the Kubernetes vs Docker debate or a variation of the question āIs Kubernetes better than Docker?ā But those are misleading because although Kubernetes and Docker are both highly popular container-related solutions, they arenāt used for the same things and arenāt in competition. Theyāre often used together. Letās dive in.
What is Kubernetes?
Kubernetes is an open-source container management tool, also called a container orchestration tool. Itās used for things like automating container deployment and scaling and descaling containers. It is not a containerization platform but rather a tool used on a containerization platform. Why would you even need a content management tool? Well, consider that youāre probably not going to be working with just one or two containers. More likely, youāll have dozens or hundreds of themāand youāll need some way to manage them. Thatās where Kubernetes comes in. This tool, introduced by Google in 2014 and widely considered the most popular of its type right now, is offered on many public cloudsāperhaps most notably on Amazon Web Services (AWS).Ā
What is Docker?
So you want to use Kubernetes to automate and scale all of your container scheduling and deployment instead of having to script each task individually, thus saving you a huge amount of work and stress. Now youāll need a platform to package up your application with its dependenciesāthat is, create the containers that Kubernetes will automate. Thatās where Docker comes in, as Docker is a containerization platform. Itās open-source (like Kubernetes), and the technology has taken off since Docker, Inc. introduced it in 2013. Lyft, Uber, eBay, and PayPal are just a few of the companies that use Docker, according to Contino.
So, as you can see, the debate about Kubernetes vs Docker is intrinsically invalid, because these solutions arenāt comparable. However, there is a Docker version of a container management tool called Docker Swarm that is comparable to Kubernetes so that we can discuss Kubernetes vs Docker Swarm.
Kubernetes vs Docker Swarm
Both Kubernetes and Docker Swarm are open-source container orchestration toolsāmeaning weāre now comparing apples to apples instead of apples too, say, apple treesāand both are major players in the container ecosystem. But they have some fundamental differences in how theyāre set up and how they operate. Before we discuss the ins and outs of Kubernetes vs Docker Swarm, you should know that Docker Swarm, often just called Swarm, is the native clustering engine by and for the Docker platform. Because Docker Swarm can turn a group of hosts into a single virtual host, itās especially handy if you want to keep deployment simple. Kubernetes, on the other hand, are generally considered more complicated (but it can also meet more complex/higher demands).
Hereās a basic breakdown of the significant differences between Kubernetes vs Docker Swarm.
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Concept
Kubernetes utilizes pods as its basic scheduling unit. A pod is composed of one or multiple containers that are located on the host machine and share resources. Docker Swarm uses clusters. A cluster is a group of machines running Docker that are joined together. -
Installation
Simple for Docker Swarm; complicated for Kubernetes. And setting up clusters in Swam requires just two commands, whereas setting up pods in Kubernetes requires several steps. -
Container Setup
Swarm offers a lot of functionality familiar from Docker, but its application programming interface (API) doesnāt entirely encompass all the Docker commands. With Kubernetes, you canāt use Docker Compose or Docker CLI to define containers, because Kubernetes uses its YAML (that is, language), API, and client definitions.Ā -
Graphical User Interface (GUI)
Docker Swarm has no GUI at all(!); Kubernetes utilizes a simple-English dashboard for ease of use.
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Networking
In Kubernetes, all the pods interact on a flat network, usually implemented as an overlay. Docker Swarm uses Linux tools to virtualize multi-host overlay networks. -
Scalability and Autoscaling
Here, it comes down to whether speed or stability is more relevant to you. Both are highly scalable, but Docker Swarm is much faster because Kubernetes is slowed down due to the way it firmly guarantees the cluster state. And Docker Swarm canāt do autoscaling, while Kubernetes can.Ā -
Load Balancing
To load-balance traffic between containers in different pods or clusters, youāll sometimes need to manually configure settings with Kubernetes. Docker Swarm does automatic load balancing as long as all the nodes are connected to the group, which is a lot easier than doing a manual intervention. -
Rolling Updates and Rollbacks
Both tools support rolling (that is, gradual and progressive) updates. But in the event of a failure, Docker Swarm doesnāt do an auto rollback to the previous working deployment, while Kubernetes does. -
Logging and Monitoring
Kubernetes has built-in tools for this, while with Swarm, youāll have brought in a third-party tool such as ELK.Ā
So whatās the verdict in the Kubernetes vs Docker debate? The answer, as youāve probably guessed by now, is that it depends on your specific needs and skill set. If youāre a beginner to containerization and your needs are minimal, itās hard to beat the simplicity of Swarm. But if youāre more experienced, if your containers are going to be highly complex, if you may need to utilize rollback quite a bit, or if stability is a high priority, Kubernetes is the way to go.
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