”Kubernetes vs. Docker” is one of the phrases in which you listen more and more these days as Kubernetes is becoming more familiar as a container orchestration solution.
However, “Kubernetes vs. Docker” is also somehow a confusing phrase. When you break it up, these words do not mean what the people expect them to be meant, as Docker and Kubernetes are not direct competitors. Docker is one of the containerization platforms, whereas Kubernetes is a container orchestrator for container platforms like Docker.
The upcoming post will clear up all your doubts related to Kubernetes and Docker.
The Rise of Containerization and Docker
It’s quite impossible to have a talk about Docker without initially examining containers. Containers sort out all the crucial issues in the life span of the application development. When creators are writing code, they are functioning in their own developed environment. When they are organized to transfer that code to the production, this is the position where problems arise. The activated code which has processed superbly on their machine does not work in actual production. The actual reason for this is different dependencies, different operating systems, and different libraries.
With the help of Containers, this critical issue of portability allows you to differentiate code from underlying the infrastructure on which it is running on. Developers can pack up their application, which consists of all the libraries and bins it requires to operate perfectly, into a small container image. In actual production, that container can easily be operated on any system which has a containerization platform.
Advantages of Containers
Additionally, to sort out the major challenge of portability, containers and container platforms give numerous advantages over traditional virtualization.
Containers have an exceptionally small footprint. The container simply requires its application and a description of all of the libraries and bins which are required to run. Unlike VMs, which have a full copy of a guest running system, container isolation is completed on the kernel stage without having any kind of need for the guest operating system. Additionally, libraries could be across containers, which eradicate the requirement to acquire 10 copies of a similar library on a server, which saves space. If there are 3 apps and all of them are in operating node and express, then we don’t proceed to have 3 instances of the node and express, those applications can transfer those bins and libraries. Approving the applications to become encapsulated in self-structured environments allows for speedy arrangements, infinite scalability, and closer parity between development environments.
What is Docker?
Docker is presently a very famous container platform. Docker came into the market at the right time and was very much open source from the starting, which probably head to its present market domination. 30% of enterprises presently use Docker in their AWS environment, and that figure is continuously growing.
When most people talk about Docker, they particularly speaking about Docker Engine, the runtime which enables you to make and run containers. But before running a Docker container they ought to be built, starting with a Docker File. The Docker File describes all the things required to operate the image which includes the OS network requirements, and file locations. Now you must have a Docker file, and you must form a Docker Image, which is the convenient, static component that gets operated on the Docker Engine. Also if you do not wish to get it started from scratch Docker, even this service is called Docker Hub, where you can save and share your images.
The Need for Orchestration Systems
While Docker provides an open standard for distributing and packaging containerized applications, which arises a new problem. How would all of the particular containers be scheduled and coordinated? How will you seamlessly update your application without any kind of interruption in service? How could you observe the strength of an application? You must be known that if anything progresses wrongly, just restart it?
Solutions for the orchestrating containers soon developed. Docker Swarm Mesos and Kubernetes, are some of the suitable choices for providing an abstraction to create a bundle of machines which acts as one of the big machines, that is important in a large-scale environment.
When most people speak about “Kubernetes vs. Docker,” what they truly meant is “Kubernetes vs. Docker Swarm.” The Docker’s have its own natural solution for Docker containers, which has the major advantage of being firmly integrated into the ecosystem of Docker and utilizes its own API. Such as most schedulers, Docker Swarm, provides a way to administrate a huge number of containers that are spread across different clusters of servers. Its scheduling and filtering system allows the choice of required nodes in a cluster to arrange containers.
Kubernetes is the orchestrator container that was established at Google, which has been granted to the CNCF, and it is currently an open-source system. It has the numerous advantage of leveraging Google’s years of knowledge in container management. It is an inclusive process for automatically deployment, organizing, and scaling of containerized applications, and assists numerous containerization tools like Docker.
Currently, Kubernetes is one of the market leaders and the standardized ways of orchestrating containers and deploy appropriate applications. Kubernetes could be easily operated on the public cloud service or on-premises; it is exceedingly modular, open-sourced, and has a dynamic community. Organizations of all sizes are spending into it, and various cloud providers provide Kubernetes as a service. Sumo Logic is also one of the organizations which provide assistance for all of the orchestration technologies, which includes Kubernetes-powered applications.
How does Kubernetes work?
It is quite simple to get detail analysis of Kubernetes, however at the end of the day, where Kubernetes performance is very simple. Cheryl Hung of the CNCF expresses Kubernetes as a controlled loop. Confirm how you want that your system must look, and Kubernetes makes that happen. Kubernetes examine the required state to the actual state, and by chance, if they are not the same then take the appropriate steps to correct it.
Kubernetes architecture and components
Kubernetes is built up of numerous elements that do not realize we are caring about each other. The elements all we tell to each other by the API server. All of these elements have their own function and then disclose metrics that we can gather for observing later on. We can list down the elements into three major parts.
1. The Control Plane – The Master.
2. Nodes – Where pods get scheduled.
3. Pods – Holds containers.
1. The Control Plane – The Master Node
The control plane is the main orchestrator. Kubernetes is one of the orchestration stages, and the control plane simplifies that orchestration. There are numerous elements in the control plane that assist in facilitating that orchestration. Etc for storage, the API server for connection in-between elements, the scheduler which describes the nodes pods should operate on, and the controller manager, important for analyzing the latest state against the desired state.
Nodes made up of the cumulatively compute capability of the Kubernetes cluster. This is the position where containers literally get arranged to run. Nodes are the natural infrastructure on which your application operates the server of VMs in your environment.
Pods are the shortest level system in the Kubernetes cluster. A pod is built up of one or more than one container, but quite common in a single container. When describing your cluster, limitations are set up for the pods which determine the resources, memory, and CPU, and they require running. The scheduler utilizes this definition to decide on which nodes to establish the pods. In case if there is more than one container in a pod, it is quite crucial to estimate the prescribed resources, and the scheduler will not be capable of suitably place pods.
How Does Kubernetes Relate to Docker?
Kubernetes and Docker both are the inclusive de-facto solutions to reasonably handle containerized applications and determine powerful abilities, and from this, some complication has emerged. “Kubernetes” is now frequently utilized as shorthand for a whole container environment, which is based on Kubernetes. In reality, they are not precisely comparable, have numerous roots, and sort out for different things.
Docker is one of the platform and devices for creating, distributing, and operating Docker containers. It provides its own natural clustering tool, which can be utilized to orchestrate and schedule containers on machine clusters. Kubernetes is one of the container orchestration systems for Docker containers, which is huger than Docker Swarm and is determine to regulate clusters of nodes at scale in manufacturing in an adequate manner. It functions around the thought of pods, which are organizing units in the Kubernetes ecosystem, and they are delivered among nodes to give high availability. One can simply run a Docker built on a Kubernetes cluster, but Kubernetes is not an absolute solution and is involved to involve custom plugins.
Kubernetes and Docker are all together basically diverse technologies, but they operate very well together, and both assist the management and distribution of containers in a prescribed architecture.
Can you use Docker without Kubernetes?
Docker is usually utilized without Kubernetes in fact, this is the rule. While Kubernetes provides numerous benefits, it is particularly complicated, and there are various scenes where the overhead spinning of Kubernetes is not necessary or unwanted.
In developing environments, it is quite natural to utilize Docker without a container orchestrator, such as Kubernetes. In production environments, usually the assistance of utilizing a container orchestrator did not overcome the cost of extra complexity. Furthermore, numerous public cloud services such as GCP, and Azure, AWS gives some orchestration abilities composing the tradeoff of the additional complications unnecessary.
Can you use Kubernetes without Docker?
As Kubernetes is one of the container orchestrators, it requires a container operating time in order to orchestrate. Kubernetes is frequently utilized with Docker, but it can also be utilized with any container operating time. Cri-o, containers, and RunC are various containers operating time which you can use with Kubernetes. The Cloud Native Computing Foundation (CNCF) handles a list of sanctioned container operating time on their ecosystem landscape page, and Kubernetes documentation gives required information for getting set up by utilizing CRI-O and ContainerD.
There are several other things to know about Kubernetes and Docker while moving to cloud. If your company is planning to move or you have already moved then it is important that you have the right set of skills and expertise of cloud platform to maintain and manage using the appropriate services. Apart from the Kubernetes and Docker management, it is also important to know about optimizing the cost and performance of the infrastructure over cloud. If you need assistance of highly experienced and certified team of AWS professionals then keep us posted at firstname.lastname@example.org