What is Kubernetes ?
K8s, sometimes referred to as Kubernetes, is an open-source platform for managing, scaling, and automating the deployment of containerized applications. The Cloud Native Computing Foundation currently maintains it after Google initially built it (CNCF).
Kubernetes offers a mechanism to scale up the deployment and management of containerized applications. It accomplishes this by offering a number of features, such as:
- Application deployment and scalability for containerized software
- Networking and load balancing for containers
- Container storage orchestration
- Automated application rollouts and rollbacks
- Self-healing features that replace broken containers automatically
Because Kubernetes is versatile and expandable by design, users may alter and expand its capabilities to suit their unique requirements. Additionally, it is made to be portable so that it may function on a range of platforms, including on-premise infrastructure, public clouds, and hybrid cloud settings.
The industry has adopted Kubernetes as the de facto standard for container orchestration, and it is extensively utilized. Small businesses to major corporations of all sizes utilize it to deploy and manage their containerized applications.
How Kubernetes works?
A master node manages a cluster of worker nodes in Kubernetes. The containerized apps are deployed and run on the worker nodes according to a schedule set by the master node, which also manages the worker nodes.
Here is a general explanation of how Kubernetes operates:
- A developer generates a Docker image for a containerized application they have created.
- A Kubernetes deployment configuration file is created by the developer, and it specifies the desired state of the application, including the number of replicas to run and the resources to be allotted to each replica.
- The application is deployed to the Kubernetes cluster using kubectl, a command-line tool for Kubernetes.
- The application is scheduled to run on one or more of the worker nodes after the Kubernetes master node receives the deployment request.
- The worker nodes run the containerized software and inform the master node of its status.
- This data is used by the master node to guarantee that the application is kept in the appropriate condition. The master node can take remedial action if any problems are found, such as restarting a failed container or moving a container to a different worker node.
Kubernetes has several advantages, including:
- Scalability: Based on resource utilization, Kubernetes may automatically increase or decrease the number of replicas of a containerized application.
- High availability: By automatically resuming failed containers or rescheduling them on healthy nodes, Kubernetes may make sure that application components are always available.
- Self-healing: Kubernetes can automatically carry out upgrades and rollbacks, as well as identify and replace broken containers or nodes.
- Workload portability is facilitated by Kubernetes’ flexibility to run on a range of platforms, including on-premises, in the cloud, and in a hybrid environment.
- Extensibility: Kubernetes can be made more functional by integrating with its extensive and vibrant ecosystem of third-party tools and services.
Flexibility: Kubernetes may be used for both development and production, allowing for the running and management of a wide range of workloads, including stateless and stateful, batch and microservices.
Kubernetes has several disadvantages, including:
- Complexity: Especially for enterprises new to container orchestration, setting up and managing Kubernetes may be challenging.
- Running a Kubernetes cluster demands a lot of resources, such as memory, storage, and computing, which may be expensive, particularly for small and medium-sized businesses.
- Learning curve: Since there are many concepts, terminologies, and abstractions to comprehend when learning Kubernetes, there is a high learning curve.
- Limited Windows support: Due to Kubernetes’ less developed Windows support compared to its Linux support, running Windows-based workloads on a Kubernetes cluster might be challenging.
- Security: Because Kubernetes includes so many moving elements and abstractions, it might be challenging to protect each one individually. It necessitates the management and implementation of extra security measures.
- Vendor lock-in: Although the Cloud Native Computing Foundation (CNCF) developed and maintains Kubernetes, several cloud providers also provide their own managed Kubernetes services, which can make it challenging to move workloads across cloud providers.