Introduction to Kubernetes
Kubernetes, often abbreviated as K8s, is an open-source container orchestration platform that automates the deployment, scaling, and management of containerized applications. It was originally developed by Google and is now maintained by the Cloud Native Computing Foundation (CNCF).
Kubernetes provides a powerful and flexible way to manage containerized applications in various environments, including on-premises data centers, public clouds, and hybrid setups.
K8s Key Concepts
The smallest deployable unit in Kubernetes. A pod can contain one or more containers that share the same network and storage resources.
A Kubernetes service provides an abstraction layer to expose a set of pods as a network service. Services allow for load balancing and DNS-based service discovery.
A ReplicaSet ensures a specified number of pod replicas are running at all times. It's used to maintain the desired level of availability and scalability.
A higher-level abstraction that manages ReplicaSets and allows you to declaratively manage the desired state of your application.
A way to create virtual clusters within a physical cluster, allowing teams to manage their resources independently.
A physical or virtual machine that runs containers. Nodes form the foundation of the Kubernetes cluster.
A set of nodes that form a single Kubernetes environment. Clusters can span multiple physical or virtual machines.
A lightweight, standalone, and executable software package that includes everything needed to run an application, including the code, runtime, libraries, and environment variables.
The control plane of the Kubernetes cluster, responsible for managing and coordinating the cluster's components.
The node where containers are deployed and run. It communicates with the master node to manage workloads.
A Kubernetes component that ensures that a desired state is maintained in the cluster. Deployments, ReplicaSets, and more are examples of controllers.
ConfigMap and Secret
Kubernetes resources for storing configuration data and sensitive information separately from application code.
Kubernetes provides a range of features for automating tasks, such as scaling applications based on demand, rolling updates with zero downtime, managing storage, handling networking, and monitoring application health. It also allows for the dynamic allocation of resources and can be extended through APIs and third-party plugins.
Kubernetes is a complex platform that requires understanding its architecture, components, and various resources. As such, there is a learning curve associated with it. However, the benefits it offers in terms of scalability, reliability, and maintainability of applications in production environments make it a widely adopted technology in the container ecosystem.