When applications become larger and more complex, what is the most effective way to host and manage web applications and other dependencies? What if there is a need to scale out a service for business needs? How do we provide services across multiple machines without cumbersome network and storage settings?
These are some questions every developer or application building enterprise asks. While the advent of DevOps has certainly automated and shortened the development-to-deployment lifecycle, the Kubernetes DevOps tool facilitates the configuration and automation process to get the best version of your software out there.
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What is Kubernetes?
Kubernetes is a portable, extensible, open-source platform for managing containerized workloads and services—with a framework to run distributed systems resiliently. It takes care of your scaling requirements, failover, deployment patterns, scaling, load balancing, logging, and monitoring, much like PaaS offerings. However, it operates at the container level rather than at the hardware level.
It was initially built upon a decade and a half of the Google experience running production workloads. Open-sourced in 2014, Kubernetes is now a growing ecosystem that combines best practices for application deployment to run some of the largest software services by scale.
The name Kubernetes is derived from a Greek term meaning ‘helmsman’ or ‘pilot.’ True to this word, Kubernetes provides the guiding force for developer platforms to transition from virtual machines (VMs) to containers and the statically scheduled to the dynamically scheduled. This means no more manual integration and configuration when you move from a testing environment to an actual production environment or from on-premise to the cloud! The Kubernetes logical compute environment offers common services to all the applications in the cluster as part of the ecosystem for the software to run consistently.
What can you do with Kubernetes?
Developers need to write applications that can run across multiple operating environments. Traditionally, the performance of these applications is dependent on a particular infrastructure, such as adherence to cloud provider-specific constructs and back-end storage systems. Kubernetes eliminates the need for one infrastructure lock-in by allowing you to deploy cloud-native applications on containers without any restrictions and manage them exactly as you like anywhere you want.
How Does Kubernetes Work?
Before we dive into how Kubernetes works, you need to first understand what containers are and why people use them. A container is a small, lightweight virtual machine (VM) that does not have device drivers and shares its operating system among the applications. It is a good way to bundle and run applications in a production environment. However, you need to manage these containers in a proper way so that there is no downtime. This is where Kubernetes comes to the rescue.
Fig: Traditional vs Virtualized vs Container Development (source)
Kubernetes works as a “container orchestration system” that manages the lifecycle of containerized applications and automates the deployment of several containers. Containers running the same applications are usually grouped together into Pods. There is a dedicated container orchestrator which supervises these groups and ensures that they operate correctly.
Why do You Need Kubernetes?
Containers decompose applications into smaller parts and enable faster development by assigning smaller, more focused teams responsible for specific containers. However, it requires a proper system for integrating and orchestrating each of these smaller decomposed parts. Kubernetes makes this possible by introducing Pods, or a collection of containers.
Fig: Kubernetes architecture (source)
There can be one or multiple containers in a single Pod and each of them shares the same IP address and resources such as memory and storage. By grouping the containers in this manner, Kubernetes eliminates the need to cram multiple functionalities in one single container.
Why is Kubernetes so Popular?
Kubernetes’ rise in popularity is due to its successful use cases in mission-critical sectors such as banking, edtech, and IT. With more and more enterprises adopting hybrid cloud strategies, there has been a number of challenges in the field of application development. Kubernetes is the perfect choice for companies that use hybrid clouds because of its consistency in both public and on-premise clouds.
Kubernetes: The Container Orchestration Tool
Kubernetes allows you to manage hundreds of containers and clusters of hosts on which containers are executed. When you deploy your containerized applications to a group of computers, Kubernetes automates their distribution and scheduling, working as an orchestration platform to simplify the work of technical teams.
Particularly, in instances when you need to manage applications with hundreds of containers spread across multiple hosts, a container orchestration tool like Kubernetes manages the workloads in a compute cluster, connecting to the outside world for scheduling, load balancing, and distribution.
The Kubernetes DevOps Tool
The container orchestration capability of Kubernetes closes the gap between IT operations and development, making a great collaborative DevOps environment for sharing software and their dependencies seamlessly between different environments.
It facilitates the software lifecycle and the enabler teams in the build-test-deploy timeline:
- Developer environment, by helping to run the software in any setting
- QA/Testing process, through coordinated pipelines between test and production
- Sys-admin, by running anything once configured
- Operations, by offering a comprehensive solution for building, shipping, and scaling software
Kubernetes has emerged as a good actor in DevOps as it focuses on features and bugs rather than time-intensive tasks to enable better software to be shipped with a smooth DevOps workflow.
Benefits of Using Kubernetes
Although we have several tools in DevOps that are equally popular like the Docker, Kubernetes wins the votes. This is because of the many benefits that far outweigh other tools.
Among its many attributes, Kubernetes:
- Lays the foundations for developing and building cloud-native applications that can run anywhere, independent of cloud requirements
- Speeds up the process of building, testing, and releasing software
- Has the ability to handle scaling-up of both applications and infrastructure in real-time
- Tackles workload scalability on the fly
- Controls resource consumption and hardware use
- Balances application load across the host infrastructure
- Moves an application to another host in the event of resource shortage
- Facilitates easy rollbacks
- Tests and auto-corrects applications
- Delivers the software quickly with better compliance
- Increases transparency and collaboration within the teams and pipelines
- Effectively minimizes security risk while controlling cost
- Increases the efficiency of server usage
- Renders health-check of your apps and self-heals with auto-placement, auto-restart, auto-replication, and auto-scaling
- Can be combined with other open-source projects to orchestrate all parts of your container infrastructure
- Supports better IT security
- Helps manage your containerized applications more easily and quickly
- Increases developer productivity
- Automates patches and updates
- Allows visibility for in-process and failed deployments with status query support
- Saves time when a deployment is paused at any time, to be quickly resumed later
- Allows version control with newer versions of application images or a rollback when the current version is not stable
- Supports container balancing as it automatically places containers by computing the best location
- Manages your batch and compute-intensive (CI) workloads for efficient batch execution
- Reduces the time to onboard new projects and applications
The benefits of Kubernetes extend beyond the development, testing, and production environment to perform mission-critical tasks in large-scale businesses.
Features of Kubernetes
Kubernetes offers the widest range of features required to deploy containerized applications.
1. Portable and Open-Sourced
As an open-source platform, Kubernetes can run containers on any number of public clouds, virtual machines, or infrastructures. Its compatibility with most platforms makes it highly flexible and usable.
2. Programming Language and Framework Support
Kubernetes supports most programming languages and frameworks.
3. Automatic Resource Bin Packing
The application is packaged, and the containers scheduled based on available resources, allowing optimal utilization of unused resources. As Kubernetes enables you to specify the CPU and RAM needs of each container, the containers can be slotted to increase compute efficiency and ultimately lowers costs.
4. Container Deployment Control
Kubernetes allows complete control over the number of containers you want with deployment and keeps those containers ready with a rollout. Thus, you can automate Kubernetes to create new containers, remove existing containers, or adopt all of their resources to a new container.
5. Automated Rollouts and Rollbacks
Versions and updates are automated and running, so you don’t waste time or resources on downtime. Also, the health of the application is screened during rollout to automatically rollback in the case of any glitch or failure.
6. Health Checks and Self-healing
It checks the health of nodes and containers to ensure than an application doesn’t fail. In case of a pod crash or an error, Kubernetes automatically restarts containers that fail, replaces or kills containers that don’t match user-defined health checks, and doesn’t make them available to clients until they are client-ready.
7. Secure Configuration Management
You can store and manage user information such as passwords and SSH keys, deploy secrets and application configuration without rebuilding your container images, and do all of this without exposing secrets in your stack configuration.
8. Service Discovery and Load Balancing
Kubernetes can expose a container using the DNS or IP address. For high traffic to a container, it can automatically balance the loads into the pods and distribute the network traffic for the stable deployment of software.
This supports the distribution of load and auto-balancing of resources instantly during incidental traffic or batch processing.
9. Storage Orchestration
You can automatically mount a storage system or orchestrate containers on multiple hosts.
10. Auto-Scaling of Resources and Applications in Real-Time
Kubernetes offers several features for auto-scaling. You can deploy and control the number of containers based on computing resources, workload balance, and scale-out your software or create applications on more containers by grouping containers in pods. Horizontal autoscaling is another feature whereby Kubernetes auto-scalers automatically size a deployment’s number of pods based on the usage of specified resources and at the individual server level.
New servers can be added or removed easily. Kubernetes can thus automatically expose your containers to the internet or other containers in the cluster to automatically load balance traffic across matching containers.
11. Heterogeneous Clusters
Kubernetes allows you to build your cluster with a mix of virtual machines on the cloud, on-premise, or in your data center, to suit your requirements.
12. Persistent Storage Support
Kubernetes workflow includes support for Amazon Web Services EBS, Google Cloud Platform persistent disks, and other storage.
13. Workload Support
Kubernetes supports a variety of workloads: stateless, stateful, data-processing.
14. Application Type Support
Kubernetes offers complete support for the application types, application frameworks, and language without differentiating between apps and services.
To get a brief understanding of the features, architecture, and working of Kubernetes, check out this Kubernetes Tutorial video -
Kubernetes has emerged as the cornerstone of DevOps. Its many benefits and flexibility make it the preferred choice of companies when they want to develop, test, and deploy their products and services. Thus, more and more companies are investing in the container management system and Kubernetes.
If you’re looking at enhancing your career prospects in DevOps or building in-depth knowledge about containerization and orchestration tools, then you must check out Simplilearn’s Certified Kubernetes Administrator (CKA) Certification Training. Learn how to build applications in containers and deploy and manage a Kubernetes cluster. Master the most trending DevOps tool, Kubernetes, to help facilitate the process of development-to-deployment.