Kubernetes is an open-source container orchestration platform that automates the deployment, scaling, and management of containerized applications. Kubernetes is basically a technology to manage your containers. It was originally developed at Google but is now maintained as part of the Cloud Native Computing Foundation.
Introduction.
Amazon EKS (Elastic Kubernetes Service) is a fully managed service provided by Amazon Web Services (AWS) for running Kubernetes in the cloud or on-premises. Amazon EKS simplifies the process of using Kubernetes by handling much of the operational complexity, allowing developers to focus on their applications instead of the underlying infrastructure. Kubernetes is set up in a cluster. It integrates with AWS Identity and Access Management (IAM), AWS Key Management Service (KMS), and VPC networking for secure access and data protection. EKS runs Kubernetes control plane instances across multiple availability zones for resilience.
How does Kubernetes work?
Master Node (Control Plane): Manages the cluster and coordinates workloads.
Worker Nodes: Run the applications in containers.
API Server: Exposes the Kubernetes API and serves as the primary entry point for interacting with the cluster.
Controller Manager: Manages controllers that handle the state of the cluster, such as replication and node health.
Scheduler: Assigns workloads (pods) to nodes based on available resources and policies.
etcd: A distributed key-value store that holds configuration data and the cluster’s state.
Kubelet: An agent running on each node that ensures containers are running as expected.
Kube-proxy: Manages network rules for communication between pods and services.
Container Runtime: Runs and manages containers (e.g., Docker, containerd).
Benifits.
- Kubernetes automatically creates the specified number of replicas, distributes them onto suitable hardware, and takes action to reschedule your containers if a node goes down.
- Amazon EKS automatically distributes control plane instances across multiple Availability Zones (AZs). Ensures high availability and fault tolerance for Kubernetes clusters without additional configuration.
- Integrates with tools like Kubernetes Cluster Autoscaler and AWS Fargate to scale resources dynamically based on demand.
- Persistent storage is abstracted by a consistent interface that works across providers, whether in the cloud, on a network share, or on a local filesystem.
- You only pay for the resources you use, including EC2 instances or AWS Fargate for running your applications. Eliminates the cost and complexity of maintaining a dedicated Kubernetes control plane.
Workload Management.
1. Nodes: Nodes represent the physical machines that form your Kubernetes cluster. They run the containers you create. Kubernetes tracks the status of your nodes and exposes each one as an object.
2. pods: A Pod is analogous to a container but with some key differences. Pods can contain multiple containers, each of which share a context.
3. Deployments: Defines how to deploy and manage a set of pods. Provides features like scaling, rolling updates, and rollback capabilities.
4. ReplicaSet: Used indirectly by Deployments. Ensures a specified number of pod replicas are running.
5. Job: Runs a specific task to completion (e.g., batch processing). It will retry any failed Pods until a specified number have exited successfully. The Job’s then marked as complete.
Conclusion.
Kubernetes is a powerful container orchestration platform that simplifies the deployment, scaling, and management of containerized applications. By understanding its basic concepts and components, you can harness its full potential to create resilient, scalable, and efficient systems. Kubernetes is a cornerstone of DevOps and cloud-native strategies, making it an invaluable tool for developers and IT professionals.
