Kubernetes vs. Docker

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To start comparing the terms Kubernetes vs Docker, it is important to keep in mind that it is not necessary to select one, but rather they are two different technologies that can even complement each other. Docker and Kubernetes are used to build, deliver, and scale containerized applications, and they work well together. 

Both Docker and Kubernetes are two of the container managers well-known software containers in the industry, and are currently the most widely used mechanisms for packaging a software application, then distributing it and running it through the use of these software containers.


What is Docker?

Docker is a software container platform that allows create, deploy, copy, and move containers from one environment to another, in order to optimize applications in the cloud. It is designed to develop, ship, and run these applications by leveraging the technology in each container.

Among the main benefits, it allows you to save resources and virtualize as little as possible to run an application. In addition, with Docker it is possible to use a wide variety of tools that are perfectly adapted to the platform, deliver all kinds of codes faster, save money by improving the use of resources and have total control thanks to its simplicity of use.


What is Kubernetes?

Kubernetes It is an open source system that allows automation, maintenance, portability and flexibility of the software executed in its containers. It is possible to schedule the deployment, scaling and monitoring of workloads and containers, and in addition can be used with or without Docker.

Unlike Docker, Kubernetes It makes it easier to manage certain operational difficulties that can arise when the number of containers deployed on multiple servers is increased. 

Google Cloud is the basis of Kubernetes, which was originally developed at Google and released as open source in 2014. At the time, the company needed a new way to run billions of containers a week at scale, and today it is the industry's standard orchestration tool. Industry and market leader for deploying containers and distributed applications. As Google points out, "Kubernetes' primary goal is to make it easier to deploy and manage complex distributed systems, while continuing to benefit from the enhanced usability that containers enable."


Advantages of Kubernetes

one of the main advantages of Kubernetes vs Docker has to do with the number of applications present in our system, since the greater the number of applications, the more complicated to manage. In this case, Docker is not enough since coordination is needed to carry out the deployment, service supervision, replacement, automatic scaling, that is, the administration of the different services that make up our distributed architecture.

Automated operations: allows you to manage when or under what circumstances a container needs to be launched. 

Service status monitoring: Kubernetes allows you to monitor failures, execution times, and other parameters of previous runs, for example you can launch a Docker from Kubernetes and see if it fails, if it completes, and in how long.

 Infrastructure abstraction: With Kubernetes you don't have to worry about the physical structure or available storage, you just build your containers. This facilitates the work of the developers, who can focus on the development of the application itself. 


automated operations

Kubernetes includes a powerful API and command line tool, called kubectl, which handles a large part of the tasks of container management heavier through the automation of operations

The Kubernetes controller allows applications and containers to run exactly as specified. Additionally this makes it easy to manage your infrastructure since all deployments/updates are handled through the same access point.


Infrastructure abstraction

What does infrastructure abstraction mean? In simple terms, this means that your developers don't have to worry about managing and monitoring resources or other infrastructure-related details that can slow down productivity and focus on developing your application code. 

Kubernetes facilitates all these processes through the API Server and its different components, which run and monitor the desired configurations. Resource management is not only easier but also automated, and the combination of the above plus the ease of containerizing applications using Docker speeds up development cycles, exponentially accelerating the delivery of projects and new functionalities.

This also contributes to the separation of concerns principle, where each container is an independent component that, when combined with the rest, forms all the services that make up your application, allowing the independent development and deployment of each component.


Service status monitoring

Kubernetes, which means helmsman or pilot, lives up to its name through the service status monitoring (Kube-controller-manager), component in charge of this task.

The kube-controller-manager constantly evaluates the current state of your cluster and compares it to the desired state (the configurations you send to the API server). If it detects a difference in the current state, this component is in charge of executing the necessary actions so that your cluster returns to the desired state, thus guaranteeing that the current state is a mirror of the desired state all the time, and removing this responsibility from the teams. of IT.


Comparison between Kubernetes and Docker

To continue with the comparison of Kubernetes vs. Docker We must explain in more depth what each one is and why we say that they can complement each other. Docker is a runtime (interval of time in which a program is executed in an operating system) From containers, while Kubernetes it is a platform to run and manage containers from many container runtimes.

Kubernetes supports many container runtimes, such as Docker, containerd, CRI-O, and any Kubernetes CRI (Container Runtime Interface) implementation. Thus, Kubernetes podría entenderse como un «sistema operativo» y, los contenedores de Docker, como las «aplicaciones» que se instalan en él.


Docker or Kubernetes: which one suits you?

As usual, docker swarm it installs faster and requires less configuration than Kubernetes if you build and run your own infrastructure. It offers the same advantages as Kubernetes:

  Deploy apps via declarative YAML files

  Automatically scale services to the desired state

  Balance load across cluster containers

  Control security and access across all your services

If you run few workloads, don't mind managing your own infrastructure, or don't need a particular Kubernetes feature, Docker Swarm can be a great option.

Kubernetes it is more difficult to install at first, but offers a greater flexibility and more functions. It is also widely supported by an active open source community. 

Kubernetes offers several out-of-the-box deployment strategies, you can manage the traffic your network receives and provides functions of container observability. All major cloud service providers offer managed Kubernetes services that make it much easier to get started with cloud-native features like autoscaling. If you run many workloads and need cloud-native interoperability, and also have many teams in your organization (which requires better service isolation), Kubernetes is the platform for you. 

If you want to know more about this platform, you can read our post about the operation and main characteristics of Kubernetes.


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