What is Kubernetes?
Kubernetes is an open-source orchestration for automating the Management, Placement, Scaling and Routing of Containers that has become popular with developers and IT operation teams in recent years. It was first developed by GOOGLE and then contributed to Open Source in 2014. Some features are:-
- Isolated environments for managing your applications.
- Easy Modeling
- Version Control
- Placement/Affinity
- Application Agility
- Developer Productivity
- Operational Efficiencies
What is Docker ?
Lets take a look at what is Docker first before seeing difference between Kubernetes and Docker.
Docker is the software that runs on the OS and supports many containerized application. Containerization is a concept that makes each application run on an OS that has its unique instance of the OS. By this, the application is said to be run in the container in such a way that it is independent and isolated from every other application and systems and get its OS instance. Docker has such many containers and each container has its specific application. Docker allows creation, running, and managing containers in just one OS.
Unlike VM’s which takes a long time and also configure the hardware in the cloud, we use Docker which virtualizes the OS and runs an isolated application on the top of Single OS. Each application with its libraries and forms the Containers.
Kubernetes vs Docker
| Parameters | Kubernetes | Docker |
| Definition | Kubernetes is used for the process of automating the scaling, fill in, managing, and get rid of containers. | Docker allows us to make containers that host isolated applications. |
| Features | Here are some features of Kubernetes:- Cluster Federation Custom Controllers Custom Scheduling Feature gates GoModules Health Checking Helm Charts PodDisruptionBudget Sidecars Taint and Tolerations | Features of Docker :- Swarm Increase productivity Security Management Easy and Faster Configuration Routing Mesh Application Isolation Services |
| Cluster Setup | The cluster setup is simple. Requires only two commands. Cluster Strength not as strong | Setup is complicated. Cluster Strength is strong. |
| Community | Open source communities and big companies like Google, Amazon, Microsoft, and IBM support Kubernetes | User communities update the software |
| Compatibility | Highly customizable and highly comprehensive | Customizable and Less extensive |
| Large Clusters | Does not consider the speed but Offers container deployment and scaling, even in large clusters | High Speed is considered for the strong cluster states |
| Public Cloud Service Provider | Google, Azure, and AWS | Azure only. |
| Optimization | Optimized for multiple smaller clusters of SDLC | Optimized for a single large cluster |
| Installation | Complicated and Time Consuming | Easy and Fast |
Now the main question is which one should be used. Docker can be used without Kubernetes, it is very challenging to use. It is system orchestration tool and can be used with docker as Containerized application.
Both do not depend on each other and can be used separately.
Kubernetes Ingress
Kubernetes Ingress is an API object that provides routing rules to manage external users’ access to the services in a Kubernetes cluster, typically via HTTPS/HTTP.
With Ingress, you can easily set up rules for routing traffic without creating a bunch of Load Balancers or exposing each service on the node. This makes it the best option to use in production environments.
Ingress is made up of an Ingress API object and the Ingress Controller.
An Ingress Controller is essential because it is the actual implementation of the Ingress API,
it reads and processes the Ingress resource information and usually runs as pods within the cluster.
An K8’s Ingress provides the functionality:
- Externally reachable URLs for applications deployed in clusters.
- Name-based virtual host and URI-based routing support.
- Load balancing rules and traffic, SSL termination.
Kubernetes Cluster
A Kubernetes cluster is a set of node machines for running containerized applications. If you’re running Kubernetes, you’re running a cluster.
At a minimum, a cluster contains a control plane and one or more compute machines, or nodes.
The control plane is responsible for maintaining the desired state of the cluster, before-mentioned which applications are running and which container images they use. Nodes actually run the applications and workloads.
The cluster is the heart of Kubernetes key advantage: the ability to schedule and run containers across a group of machines, be they physical or virtual, on-premises or in the cloud. Kubernetes containers aren’t tied to individual machines. Preferably, they’re abstracted across the cluster.
Kubernetes Secrets
There are many times when a Kubernetes Pod needs to use sensitive data and that’s where Kubernetes Secret is used. Think for examples of:
- SSH keys.
- Database passwords.
- OAuth tokens.
- API keys.
- Image registry keys.
K8’s secret is something that provides to protect sensitive information in a way that limits accidental exposure and provides flexibility. It means putting information in a Secrets is safer and more flexible, putting it verbatim in a pod definition or in the container image.
