Kubernetes vs Docker

There are many reasons why people come to use containers and container APIs like Kubernetes, but we believe they can all be traced back to one of these benefits:

1.       Velocity

2.       Scaling (of both software and teams)

3.       Abstracting your infrastructure

4.       Efficiency

Kubernetes also provides a concrete economic benefit to the abstraction. Applications can be accumulated on the same machines without impacting the applications themselves. This means that tasks from multiple users can be packed tightly onto fewer machines.

Docker runs on each of the worker nodes and runs the configured pods. It takes care of downloading the images and starting the containers.

Docker will manage the production and deployment of each application container; Kubernetes manages multiple containers in clusters across platforms.

Docker and Kubernetes both have the same functionality, but they handle the issues in different ways.

Why Kubernetes?

1.       Kubernetes has Flexibility for orchestrating a large cluster of distributed containers.

2.       Kubernetes provide resource-efficient deployment along with synchronization.

3.       Capability to scale and manage of multiple container applications.

Kubernetes Features -:

Installation
Kubernetes installed manually, and the process would be different based on the provider as well as the operating system.

Docker is installed with the use of a one-line command (install docker-engine -y) in Linux.

Scalability
Kubernetes works with its built-in horizontal auto scaling feature.

It adjusted node Dynamically when load increases.

Docker does not have any feature for auto scaling, but Docker Swarm has a feature of scalability that could be handled automatically.

Availability
Kubernetes has high availability of services along with its most significant self-healing and intelligent scheduling features.

Docker does not have any capability like this, But Docker Swarm can do in different way.

Load Balancing
Kubernetes provides functionality equivalent to type equals ClusterIP to pods within the cluster and extends it by programming the (external to Kubernetes) load balancer with entries for the Kubernetes pods.

Docker is internal load balancing, according to the assigned DNS names, the requests are delivered to the balancer. The load is distributed among the internal and external load balancers.

Kubernetes architecture based on cluster.

1.       Set of nodes.

2.       physical Machine

3.       virtual machines.

For achieving High availability, to avoid interruption more than one master nodes work in cluster.
The system is composed of a master node and any number of worker nodes. When the developer submits a list of apps to the master, Kubernetes deploys them to the cluster of worker nodes.

Master Node and Working Node
In worker node Pods are smallest unit which helps to run Containerize application.

A pod of containers allows you to run closely related processes together and provide them with (almost) the same environment as if they were all running in a single container, while keeping them somewhat isolated. This way, you get the best of both worlds. You can take advantage of all the features containers provide, while at the same time giving the processes the illusion of running together.

COMPONENTS RUNNING ON THE WORKER NODES The task of running your containers is up to the components running on each worker node:

1.    The Kubelet

2.    The Kubernetes Service Proxy (kube-proxy)

3.    The Container Runtime (Docker, rkt, or others)

Docker uses a client-server model architecture with key component.

1.       Docker Client

2.       Docker Host

3.       Network and Storage components

4.       and the Docker Registry / Hub

Docker Key Feature

1.       Faster and easier configuration.

2.       Application isolation.

3.       Increase in productivity.

4.       Swarm.

5.       Services.

6.       Routing Mesh.

7.       Security Management.

8.       Rapid scaling of Systems.

Docker and Kubernetes Work Together?

Docker and Kubernetes work together very smoothly and complement each other.

Docker and Kubernetes technologies help us run more scalable and robust applications.

Docker use for packaging and shipping the app and create containers

Kubernetes allows us to manage containers create by docker   at runtime.

Docker and Kubernetes develop and run applications in well-structured way.

Conclusion

This comparison blog, helps to understand the basic difference between Kubernetes and Docker. Architecture and key features for both technology are explained. The blog also covers how Kubernetes and Docker help each other in the application development process.