In recent days, cloud computing has seen the debate of Kubernetes versus Docker raised on many occasions than once. This article will try to shed some lights on the matter and I hope that at the end, you will be able to make an informed decision.
The main Relationship between Kubernetes and Docker
Comparing Kubernetes vs Docker is pretty much absurd because one is not a direct alternative of another. It is like an apples-oranges comparison. The relationship between the two is not mutual, Kubernetes can work without Docker and on the other hand, Docker can run without Kubernetes. But the two can greatly benefit from one another.
So what are these two animals and how do the function?
If you are seeking to build a modern cloud framework or looking for an implementation of DevOps, then it is important to understand the idea of Kubernetes and Docker.
In the study of the two, you will come across the term container, containerization, and container orchestration.
Let’s look at the quickly,
A container is a software package containing the code of an application, configurations, along with dependencies, which provides operational and productivity efficiencies. With a container, everything is predictable, and you can know how the package will run, it is however immutable and repeatable. The upsurge in containers has directly contributed to the growth of DevOps as Service and it is hoped that it can help overcome the security hurdle.
Containerization enables the applications to be portable via virtualizing at the level of the operating system and generating isolated as well as encapsulated systems that are kernel based. Containerized applications can be placed and run anywhere without needing an entire VM or any dependencies.
This is the process of deploying more than one container to implement an app by means of automation. Platforms such as DockerSwarm and Kubernetes functions as container managers as well as container orchestration engine, which allow the user to monitor container deployment as well as automating updates, monitoring health and failover procedures.
Let’s start with Docker
Docker is a standalone system, or a content management service that can run applications in containerization. Docker helps developers design an app and allow for easy creation, deployment and running of applications with the help of containers. The built-in mechanism called “swarm mode” in Docker is used for clustering containers. With this built-in mechanism, developers can use the Docker Engine to run applications across different devices.
Docker Swarm is tightly integrated into the Docker network and uses its standalone API. It monitors the containers spread across groups of servers, making it easy to create a clustered Docker app minus the need for extra hardware.
Advantages of using DockerSwarm
- Run faster: with DockerSwarm, you won’t encounter problems such as tedious booting up procedures because it allows the application to run in a virtual environment that is software-defined and helps implementation of DevOps.
- Helpful documentation: the team behind Docker stands out with their documentation, which includes every bit of necessary information that is updated.
- Offers simple, fast configuration: Docker Swarm simplifies everything, by enabling developers to put their own configuration in a code and then deploy it hassle-free.
- Ensures the isolation of application: Docker Swarm ensures that containers are isolated and that have their own resources.
- Reuse of component and version component: Developers using Docker Swarm can track the successive versions of a container, observe the differences or roll-back the earlier version. Containers recycle components from previous layers, thus making them noticeably lighter.
Disadvantages of using DockSwarm
- Docker is not an independent platform: One of the drawbacks of Docker Swarm is that it is Linux agonistic platform, and uses virtual machines to function on non-Linux devices. Another thing is, applications built to run in Docker container in Linux can’t run on Windows and vice versa.
- No storage option: Docker Swarm does not offer a stress-free means of linking containers to storage, and this is among the major drawbacks of the platform.
- Poor monitoring: Yes, Docker Swarm provides rudimentary information about the container as well as basic information about monitoring solution, but if you want advanced monitoring, Docker Swarm is not an option.
How do you assuage these shortcomings? Kubernetes can be an answer.
Kubernetes is an open source platform for handling the containerized application in a clustered setting. When used in the right way, Kubernetes can assist the DevOps as a Service crew to scale up and down the application automatically and quickly update.
Advantages of using Kubernetes
- It is fast: Kubernetes is a perfect choice when it comes to deploying continuously new features without any interruption.
- Sticks to the principles of immutable infrastructure: in immutable infrastructure, you can update any application as long as you create a container image with a different tag and deploy it, in the process, killing the old container with old version image.
- Offers declarative configuration: Developers can know in what condition the platform should be to avoid errors. Traditional tools such as unit tests and source control cannot be used with imperative configurations but can be used with declarative configurations.
- Auto-scaling: Depending on the CPU resources usage or other application metrics, users can change the number of running containers.
- Manual-scaling: Users can manually scale the number of containers running through the interface or a command.
- Horizontal Infrastructure Scaling: To efficiently apply the horizontal scaling, operations should be run at the individual server level, while new servers can be added or detached hassle-free.
Disadvantages of using Kubernetes
- Takes time to initialize: when a new process is developed, a developer has to wait for the application to initialize before it is accessible to the users.
- Tedious installation process: It is not easy to install Kubernetes on your cluster unless you are using a cloud provider such as Google, Amazon or Azure.
The question of Kubernetes vs. Docker is useless. It doesn’t matter which one you choose as both are considered great and possesses some differences. The big question you should ask yourself is which of the two you have sufficient knowledge of. If you are seeking to build a simple app, then go with the Docker but if you want to create a complex application, use Kubernetes.