"Unleash Your DevOps Wizardry and Conquer the Container Kingdom!"
What is Kubernetes?
Kubernetes is an open-source container orchestration platform that automates the deployment, scaling, and management of containerized applications. It provides a robust infrastructure for managing container workloads and abstracts away the complexities of managing individual containers, allowing teams to focus on application development and deployment.
Kubernetes is from the Greek word pilot or helmsman, and its abbreviation is K8s. K8s stand for the eight letters counted between the “K” and the “s.” Google designed Kubernetes and open-sourced the project in 2014, but the Cloud Native Computing Foundation now maintains it.
Kubernetes works with Docker, Containerd, and CRI-O. Initially, it interfaced solely with the Docker runtime through a “dockershim;” however, from 2016 until April 2022, Kubernetes deprecated the shim over direct interfacing with the container through Containerd or substituting Docker with a runtime compliant with the Container Runtime Interface (CRI). Eventually, with the May 2022 release of v1.24, “Dockershim” was removed.
Companies currently offering Kubernetes-based Platforms or Infrastructures as a Service (PaaS or IaaS) that deploys Kubernetes are Google, Amazon, Microsoft, IBM, Oracle, VMware, Hat, Red Platform9, and SUSE.
Why you need Kubernetes and what it can do
Containers are a good way to bundle and run your applications. In a production environment, you need to manage the containers that run the applications and ensure that there is no downtime. For example, if a container goes down, another container needs to start. Wouldn't it be easier if this behavior was handled by a system? That's how Kubernetes comes to the rescue! Kubernetes provides you with a framework to run distributed systems resiliently. It takes care of scaling and failover for your application, provides deployment patterns, and more. For example: Kubernetes can easily manage deployment for your system. Kubernetes provides you with:
Service discovery and load balancing Kubernetes can expose a container using the DNS name or using their own IP address. If traffic to a container is high, Kubernetes is able to load balance and distribute the network traffic so that the deployment is stable.
Storage orchestration Kubernetes allows you to automatically mount a storage system of your choice, such as local storages, public cloud providers, and more.
Automated rollouts and rollbacks You can describe the desired state for your deployed containers using Kubernetes, and it can change the actual state to the desired state at a controlled rate. For example, you can automate Kubernetes to create new containers for your deployment, remove existing containers and adopt all their resources to the new container.
Automatic bin packing You provide Kubernetes with a cluster of nodes that it can use to run containerized tasks. You tell Kubernetes how much CPU and memory (RAM) each container needs. Kubernetes can fit containers onto your nodes to make the best use of your resources.
Self-healing Kubernetes restarts containers that fail, replaces containers, kills containers that don't respond to your user-defined health check, and doesn't advertise them to clients until they are ready to serve.
Secret and configuration management Kubernetes lets you store and manage sensitive information, such as passwords, OAuth tokens, and SSH keys. You can deploy and update secrets and application configuration without rebuilding yo
What is Kubernetes Architecture?
Kubernetes is an architecture that offers a loosely coupled mechanism for service discovery across a cluster. A Kubernetes cluster has one or more control planes, and one or more compute nodes. Overall, the control plane is responsible for managing the overall cluster, exposing the application program interface (API), and for scheduling the initiation and shutdown of compute nodes based on a desired configuration. Each of the compute nodes runs a container runtime like Docker along with an agent, kubelet, which communicates with the control plane. Each node can be bare metal servers, or on-premises or cloud-based virtual machines (VMs).
What are Kubernetes architecture components?
When you deploy Kubernetes, you get a cluster. A Kubernetes cluster consists of a set of worker machines, called nodes, that run containerized applications. Every cluster has at least one worker node.
The worker node(s) host the Pods that are the components of the application workload. The control plane manages the worker nodes and the Pods in the cluster. In production environments, the control plane usually runs across multiple computers and a cluster usually runs multiple nodes, providing fault-tolerance and high availability.
Most Important Elements of Kubernetes:
Pods: Pods are the fundamental units of deployment in Kubernetes. They encapsulate one or more containers, share a network namespace, and can communicate with each other via localhost. Pods enable co-located containers to work together, forming the basic building blocks of applications.
Real-Life Application Example: In a microservices architecture, each microservice can be deployed as a separate container within a pod, allowing efficient communication and scalability. For instance, Netflix utilizes Kubernetes pods to manage various microservices like user authentication, content delivery, and recommendation systems.
ReplicaSets: ReplicaSets ensure the desired number of pod replicas are running at all times, providing high availability and fault tolerance. They monitor pods and automatically create or terminate replicas as necessary, maintaining the desired state of the application.
Real-Life Application Example: A popular e-commerce platform leverages ReplicaSets to ensure multiple instances of its shopping cart microservice are always running. If any pod fails, the ReplicaSet creates new replicas to meet the desired availability, ensuring uninterrupted shopping experiences for customers.
Deployments: Deployments allow for declarative updates and rollouts of application versions. They provide mechanisms for managing application updates, scaling, and rollback capabilities. Deployments enable seamless and controlled deployments, minimizing downtime and ensuring smooth transitions.
Real-Life Application Example: A ride-sharing service can utilize Kubernetes deployments to update its driver application. Deployments ensure zero downtime during the update process, gradually rolling out new versions to driver devices without disrupting ongoing rides.
Services: Services provide a stable network endpoint for accessing a group of pods. They abstract away the complexities of pod IP addresses and enable load balancing, service discovery, and communication between pods.
Real-Life Application Example: A social media platform employs Kubernetes services to expose its backend microservices to the front-end application. Services provide a single access point for frontend instances to communicate with the backend microservices, ensuring seamless user experiences across different regions.
Signing Off
Remember, Kubernetes is a powerful platform that empowers businesses to deploy and manage applications efficiently. By mastering its elements, you can unleash the full potential of Kubernetes and revolutionize your application deployment processes. Happy learning!
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