Kubernetes Vs. Docker

Pros

Cons

• Companies that want to generate steady revenue over the long term can take advantage of docker because it provides the best ROI.
• By using Docker the time required to build an application can be brought down to seconds. And without worrying about the various kinds of OS and switching between them you can deploy your application.
• Docker ensures security as it ensures that the applications which are running on containers are segregated and isolated from each other and gives us complete control over traffic flow and management.
• Docker allows users to take their own configuration and put it into the code and deploy it without any hassles. However, with the new docker features, there are no dependencies to infrastructure, as Docker can be used in various environments.
• After building the container image developers can further use that image over every step of the deployment process. The feature, like the ability to run non-dependent steps, and running them in parallel, reduce the time involved in build to production.
• Docker comes with Continuous Integration and it works well with the pipelines while using tools like Travis, Jenkins, and Wrecker. These tools can save new versions as Docker images and with the tag and its version number and publish it to the Docker hub where they are deployed to production.

• It lacks certain features like container self-registration and copying files from the host to the container, and many other features as well.
• Sometimes the container goes down and to rectify it you need a backup and recovery strategy. Although that can be easily solved but not an automated way.

• If an application is designed to run using a Docker container on Windows, it can’t be run on Linux or vice versa. With virtual machines, there is no such limitation and due to this reason, Docker is less attractive when it comes to heterogeneous environments, which are composed of various operating systems.
• It’s a known fact that to use Docker or to host applications on Docker we need to run the command line but certain features can be used to make it possible to run a graphical user interface inside a docker container. However, its graphical user interface is not so good that’s why people don’t prefer it.
• There are challenges like the difficulty of monitoring multiple moving pieces within a large-scale or dynamic docker environment. These are docker-specific security risks and in such scenarios, the security needs to be looked upon when it comes to Docker.

Pros

Cons

• Kubernetes has self-healing abilities for pods and its further integration of the self-healing layer also provides application reliability.
• Kubernetes draws essential computing resources and allows developers to develop and deploy workloads to the whole cluster instead of a particular server.
• Using Kubernetes, a single administrator needs no one to monitor several simultaneously running containers.
• Kubernetes offers workload portability with no restriction to the type of application. If an application that can run using a container can be managed through Kubernetes.
• To effectively balance the load, Kubernetes provides individual IP addresses for every pod and a single DNS name for a group of pods.
• Kubernetes is a low-cost solution, as it requires less computing resources and can be used to set maximum or minimum limits for the CPU and memory resources accordingly.

• Kubernetes is good for bigger organizations or projects but when it comes to the local development environment it can diminish the productivity or negatively affect the present timelines of the organization.
• Since Kubernetes keeps on innovating and has too many additions, its landscape can be confusing for new users, which makes the transition to Kubernetes slow or complicated.
• Learning Kubernetes is a bit difficult and to implement it within your organization, you need an expert, which proves to be an expensive option.
• To fix bugs and troubleshooting in Kubernetes environments, you need extensive experience. Since new deployments or new additions are being made to it, adapting to a new system can be overwhelming.

Kubernetes

Docker Swarm

Installation and Cluster

If you are installing Kubernetes in a smaller configuration environment then it won’t be difficult but if you want to scale it further, it requires more planning and effort. And to do so much planning, you need to run separate steps for each function like:

• Bringing up the cluster.
• Defining the environment.
• Defining a pod network that enables the containers to interact.
• Setting up the dashboard.
• Hosting the cluster.

Docker Swarm uses Docker CLI. Since here you need a single set of tools to run those commands to build the environment and configure, you don’t need to follow many steps, as Swarm programs run into your current docker.

Building and Running Containers

Kubernetes has its own API, client, and YAML definition. If you compare these to Docker Swarm you will find that Kubernetes has more to offer when it comes to defining containers.

To build new containers Docker CLI is used, though Swarm supports multiple tools that work with Docker, yet it could be a hassle if you want to perform specific operations in Docker.

Logging and Monitoring

Kubernetes has some inbuilt tools for logging and monitoring. Logging lets users understand the case of failure by seeing the past records or logs. Contrary, monitoring enables users to constantly check the health of nodes and services that are containerized by these nodes.

Docker Swarm does not have inbuilt tools to handle tasks such as logging and monitoring. However, you can take advantage of the third-party tools to perform these tasks.

Scalability

To maintain the strength of the clusters, Kubernetes is the best choice as compared to Swarm. However, it is not easy to scale with Kubernetes because of the complexity its APIs produce. Also, its strong focus on the cluster states makes it difficult for the users. But when it comes to autoscaling it is way better than Swarm as it can automatically analyze the server load and adjust with your requirements.

Docker Swarm is known to perform scalable tasks better than Kubernetes. Swarm containers can be deployed faster when it comes to handling large clusters. To deploy new replicas of containers, you need to run a single command. On the other hand, it also allows auto-scale as smoothly as Kubernetes.

GUI

If you are comfortable working with dashboards then you will love Kubernetes because its GUI provides a reliable dashboard that can be used to control the cluster. Even if you are not from a technical background you can use it easily because it provides simple and plain instructions.

Docker Swarm doesn’t have its dashboard to manage clusters but you can use third-party tools like Portainer.io that provide good UI.

Load Balancing

In Kubernetes, load balancing is permitted when container pods are defined as services. Besides this, you need to manually configure these settings, and only a certain set of pods and policies give access to each service.

In Docker Swarm, there are inbuilt facilities for load balancing, where a common network joins all containers that are in the same clusters. This way it allows the connection of any node to any container.