The practitioners working on the deployment of software applications must have heard about Docker and Kubernetes. As the technology is consistently improving, the deployment and innovation techniques are also improving and everyone wants such things to happen robustly. Docker and Kubernetes are major tools for making the performance of the application robust and powerful. In this article, we will discuss a basic overview of these tools along with understanding a comparison between them. The major points to be discussed in this article are listed below.
Let’s start the discussion by understanding the containers.
About Containers
Let’s start by thinking of any multitasking software. We can say that multitasking software is a group of many software. The success of a software depends on its performance and a container can be considered as a standard unit of this software that is basically a package that holds all the codes and the dependencies of the software. The main reason behind applying containers in the software architecture is to make the performance of the software robust and reliable for any environment.
Images under the container can be considered as the standalone package of the software which is lightweight at the execution timings. These images hold every requirement to run the software like codes, runtime, tools, libraries, and other settings. When we run any of the software from the group, its container image becomes a container at the runtime. The below image is a representation of the containerized applications.
Here we have an overview of containers. Now let’s understand why we need containerization.
Why is Containerization Required?
In the above, we have seen what the containers are and we can understand that we are required to run any application or software from the group only when it is required to run so that we can obtain optimal performance from the software. By containerization of the application, we can achieve a high range of acceleration in the deployment and innovation cycles of the application.
Now we can think of containers as the packaging of micro software that helps in separating the software contained by the image from the whole environment. In the environment, the operating system and infrastructure of the container can be considered as the affecting components.
We can take an example of shipping containers in the transport industry to understand containerization of the application wherein the container in shipping hold materials of the same characteristics and in deployment they can be used in various applications similarly we can think of container image as a container and various container images can be merged to make a whole application which is not affected by the environment where they are getting used. Also, these images can be used with any other application.
We can understand how useful and important containerization is. Let’s take an example of a small team in the development where members of the team can develop and rap their application on their laptop and when it is required, they can deploy the application anywhere in production or staging environment where they don’t have to be worried about the requirement of the environment like dependencies, configuration, operating system, etc. we can say we use containerization to make the deployment and innovation cycles robust without worrying about the environment.
Here we have seen why we need containerization of the application. Now we can discuss Docker, which we can say is synonymous with the container.
What is Docker?
Docker is a set of platforms as a service product that can be considered as the tool which helps in containerization. At the same time, we can say that Docker is more than a container, or we can consider Docker as a field in the development of the application where a developer can build, share and run the containerized applications. This field is mainly made up of five components, which are named as follows.
- Docker Build
- Docker Compose
- Docker Hub
- Docker Engine
- Docker Swarm
Docker Build: As the name can suggest, it is a tool for building container images. These container images are the blueprint for the container. And as we have discussed earlier, images are responsible for holding every requirement of the application for making it work.
Docker Compose: Using this tool of Docker, we can define and run multi-container applications. It can be compared to GitHub where it is integrated with applications by holding the repositories of codes.
Docker Hub: It is a registry where every developer of the team can share images built using the Docker build with the team. It helps developers in making transparency in development with the other members of the team.
Docker Engine: It can be considered as the containerization technology which is also a container that helps in running other containers and can run in almost every environment. Some of the examples of environments where the support for the Docker engine can be found are mac OS, Windows, Linux, cloud, etc.
Docker Swarm: It is helpful in running different Docker engines at the same time and also helps in managing clusters of Docker engines.
Here we have seen what Docker is. One of the major components of the Docker swarm is that it helps in automating configuration, management, and coordination of computer systems. Basically, it is a built-in orchestration. Kubernetes is also an orchestration platform. Let’s start by understanding what orchestration is.
What is Orchestration?
In computer programming and computer administration, orchestration is the automated coordination, configuration, and management of computer software and systems. When we talk about orchestration in containerization, it is the process of aligning working container images with their application in the overall project. More formally we can say orchestration is a way of achieving larger goals and objectives that includes a workflow and provides a way to predefined action.
The goal of any containerized application can be to achieve high application performance without losing so much cost. Here we have already defined the Kubernetes as a platform for orchestration. Let’s have an overview of Kubernetes.
What is Kubernetes?
Like Docker swarm, Kubernetes is also a tool for container orchestration. But because of its flexibility and capacity of the scale, we can consider it as a de facto standard for orchestration. Various small and big organizations use the Kubernetes for automating their containerized applications. Using such tools is a more sensible option rather than managing containers separately.
Although containers are a good way to deploy and run the application, in production, there are various tasks related to the management of the containers. To complete this purpose Kubernetes comes to help us. With the help of Kubernetes, we can ensure that the application is always running at a high time. Also, there are various facilities that can be utilized using the Kubernetes. One of the major benefits of using the Kubernetes is that it operates on the container level, unlike traditional systems where we need to make the system operate on the hardware level. Some of the other facilities from Kubernetes are as follows:
- Service discovery and load balancing
- Storage orchestration
- Automated rollout and rollbacks
- Automated bin packing
- Self-healing
- Secret and configuration management
There are various traditional systems that can be used in place of Kubernetes, but the major problem of replacement is they don’t provide such facilities. Seeing these facilities and knowing what Docker and Kubernetes are, let’s take a look at the differences between Docker swarm and Kubernetes.
Kubernetes vs Docker Swarm
With the understanding so far, we can say Docker is an overall tool for containerization of the application and Kubernetes is a tool that helps in orchestration. It is better to call this section Kubernetes vs Docker swarm because both of them have a single purpose of orchestration.
When we talk about the Docker swarm which in runtime can be considered as a Docker in swarm mode is one of the easiest ways to deploy the orchestration in containerized applications. So at any point where an organization is new and using Docker as a beginner, uses swarm because it covers almost 80% of the facility from the Kubernetes and is also easier in deployment than the Kubernetes.
When we talk about the Kubernetes, we can say the deployment is complex but it is the choice of many big companies because it is developed by the google team and the most important factor is that it is supported by almost all public cloud vendors like AWS, Microsoft Azure and Google Kubernetes. And also, it has a rich technology ecosystem, including various open-source frameworks designed to monitor and maintain containers.
After these major differences still there are various minor differences between the swarm and Kubernetes orchestration tool. Some of them are listed below.
| Docker swarm | Kubernetes | |
| Installation | Esiar | complex |
| Robustness | Powerful but complex | Lightweight but limited functionality |
| Auto Scaling | Yes | No |
| Monitoring | built-in | Third-party monitoring |
| Load balancer | manual | auto |
| CLI tool | Requires new CLI | Integrated with Docker |
Final Words
Here in the article, we have seen an overview of containers in the field of the application deployment. Along with that, we have seen how Docker helps in containerization and how Kubernetes helps in the orchestration of the containers. Docker also has swarms for orchestration but Kubernetes is somewhere better than the swarm in Dockers for orchestration of contained applications.
