Google developed Kubernetes as a content management system that essentially controls a containerized application in different types of Virtual, Physical, and even cloud environments. Kubernetes is a flexible tool and can help developers consistently deliver complex applications including enterprise applications. The main purpose of Kubernetes is to make the work of technical teams easier by ensuring that app processes and deployment are automated.
Kubernetes has a rapidly growing ecosystem as it brings in a framework for running distributed systems. Kubernetes allows you to make sure that these containerized systems are running where and when you want and allows you to uncover the tools and resources you need to work with.
Here are the 10 Key Features of Kubernetes:
- Custom Controllers: Loops that regular the state of your resources or system are known as Controllers. Standard controllers may present some limitations in terms of tasks, however, with custom controllers you can move beyond these limitations. While custom controllers can be combined with any resource, they become more effective when custom resources are combined with them. Custom Controllers are utilized to encode domain knowledge for particular applications.
- Go Modules: Collections of Go Packages or Go Modules can be utilized to manage a specific application’s dependencies. An application depends on parts of code, libraries, and frameworks to run and these are the dependencies. From v1.15 onwards, Kubernetes supports these Go Modules. Go Modules allows you to make use of Multiple versions of a singular dependency or utilize dependencies stored in multiple environments. These modules can also help you in minimizing the impact of modifications in dependencies as they make code sharing easier between distributed teams.
- Service Discovery: Pods that operate through clusters uniformly are provided with network connectivity by Services. All Services have a permanently fixed IP address and port. To access a service, you need to bind to the port number or IP address from within an application. Two primary modes of service discovery are supported by Kubernetes, namely, Environment variables and DNS. The simplest way, however, is to discover services through DNS as it does not need any custom client-side code, magic libraries, or dependency injection.
- Networking Options: A network needs to be set up properly to manage a cluster comprehensively. Kubernetes offers a wide arena of networking options and also supports Container Networking Interface (CNI), a known plugin architecture for containers, now. Kubernetes is flexible as it allows developers to select the perfect networking options specific to their deployment environment and their needs. The Kubernetes networking models help us understand how Kubernetes pods, containers, and services communicate with each other. It ensures simplification and consistency across all network implementations.
- Secret and ConfigMap: The Secrets feature is used to store and secure sensitive data such as SSH keys, OAuth tokens, and passwords. While ConfidMap facilitates configuration management while keeping the container image the same across various environments. In other words, you can update the app configuration, secrets, and deploy without the need to rebuild these container images or revealing any secrets in a stack configuration.
- Logging: The purpose of logs is to help users learn what occurs within their application and useful for keeping a track of cluster activity and bugs. Almost all applications have a logging mechanism. In Kubernetes, the logs from containers get automatically deleted when an app dies, and thus it is important to integrate a centralized log management solution. Kubernetes clusters complicate logging furthermore by adding new layers generating new types of logs that need to be looked into.
- Pod Disruption Budget (PDB): The PDB feature allows users to limit the pods in a cluster that can be stopped voluntarily. This feature helps developers keep an application’s performance or availability unaffected by administrative tasks. It ensures that some pods continue to work even during maintenance, upgrading, or auto-scaling down. However, it is important to note that the Pod Disruption Budget feature only works when changes are made manually and this feature will not function if a node fails.
- Sidecars: This feature allows users to deploy an additional container to work as a watcher or proxy, within a pod. Sidecars can be utilized to allow relevant processes to communicate within a pod, without having to update the primary container source code. While a normal container needs to address a specific concern only, the sidecar pattern allows a container to extend its original functionality and take up supplementary tasks.
- Health Checking: A Kubelet agent is responsible for health checking in Kubernetes. Also known as probes, these health checks determine when a container should be restarted. To ensure that the operations are reliable, Kubernetes performs liveness and readiness probes. While the liveness probe examines if an app is alive or dead. The Readiness probe determines if an app can process and serve requests.
- Feature Gates: This functionality allows developers to turn the features on or off on a cluster, node, or even at the platform level. Feature Gates help developers to test features safety without risking or losing the production environment or the critical components. Feature gates can be used to control three types of features: alpha, beta, or stable. While the Alpha features are off by default, the beta and stable features stay on. One feature gate can be used to control only one feature.
For orchestrating container deployments, there is no better tool than Kubernetes, though it is a bit difficult to work with. The only way you can derive some benefit from Kubernetes Is by understanding its core features. Kubernetes allows you to manage and automate updates and deployments, cut costs by optimizing the use of hardware and autocorrects applications.