Kubernetes. Future of a containers management.

All of the companies are searching the new ways to accelerate an innovations and functionality of operations. Because of this, it is constantly changing the mean that applications are designed, habituated, scaled and managed in order to assured new modes to improve efficient as well increasing innovation. Kubernetes (K8S) was commonly accepted by almost all interested radical acceleration of application delivery thanks to the container and native cloud loads.

What is Kubernetes?

Kubernetes is an open source system for managing container clusters and services that simplifies configuration and automatization. For this purpose it provides tools to implementing the application, scaling applications according to need, managing changes in existent container applications, and it helps to optimize the using equipment under the containers. Kubernetes has been established in the way to make it extensible and resistant to damage, enabling components of applications to be restarted and cross over applications, if it is necessary.What is container orchestration?

What is container orchestration?

Container organization relies on container lifecycle management, especially in large, dynamic environments. Containers’ orchestration is used to control and automate many tasks such as:

• Supplying and implementing containers
• Redundancy and availability of containers
• Scaling or removing containers in order to distribute the application load over the host infrastructure
• Moving containers from one host to another if in the host is out of supplies
• Resource allocation between containers
• External display of services operating in a container with the outside world
• Balancing the service discovery load between containers
• Monitoring the status of containers and hosts
• Application configuration in relation to running containers

How does the Kubernetes platform work?

The Kubernetes platform provides an open source API interface that allows to control how and where these containers will be run. Moreover, you can organize a cluster of virtual machines and arrange the running of containers on these virtual machines based on their available computing resources and requirements of individual containers resources.

K8S facilitates to services discovery management, enabling load balancing, tracking resource allocation, scaling based on the use of computational resources, checking the condition of individual resources, and enabling a stand-alone application by automatically restarting or replicate containers.

Here are the basic parts of Kubernetes:

Kubernetes clusters

The cluster, the highest level of Kubernetes abstraction, refers to a group of computers running K8S (it is a cluster application itself) and the containers it manages. The Kubernetes cluster must have a layout, a system that commands and controls all other K8S machines in the cluster. The highly available Kubernetes cluster replicates master devices on many computers. But only one master manages the task schedule and the controller manager at a time.

Kubernetes Node (nodes)

Nodes are containe in clusters. They can be physical machines or virtual machines. in clusters. They can be physical machines or virtual machines. Regardless in which application it is working, Kubernetes supports deployment on this foundation. Kubernetes even allows you to ensure that some containers only work on virtual machines.

Kubernetes Pod (trays)

Nodes run containers, the most basic Kubernetes objects that you can create or manage them. Each pod represents a single instance of the application or running process in Kubernetes and consists of one or more containers. The containers pay the user’s attention to the application. Detailed informations on Kubernetes configuration are stored in Etcd, distributed store of keys and values.

Pods are created and destroyed in nodes as needed to adapt to the desired state specified by the user in the definition of pods. Kubernetes provides an abstraction called a controller. Controllers are available in several different versions, depending on the type of application being managed, and they deal with development management.

Service Kubernetes

The Kubernetes service describes in which way you can get access to the group of containers (or other Kubernetes objects) via the network. As Kubernetes documentation puts it, pods may change, but the interface should not know or follow him. Services allows it.

A few more internal elements for Kubernetes complete the picture. The scheduler distributes the loads into nodes thanks to they are balanced between resources and and deployments meet the application definition requirements. The controller manager ensures that the system state – applications, loads, etc. – matches the desired state defined in the configuration settings.

Belongs to remember that none of the low-level mechanisms used by containers, such as Docker, are being replaced by Kubernetes. Instead, Kubernetes provides a larger set of abstractions to use these mechanisms to keep applications running on a large scale.

Kubernetes attributes

Automatic placement

The packaging problem (container packaging problem) has been resolved, and Kubernetes automatically places containers based on requirements to optimize owned resources. Maximizes utilization and at the same time ensures that the critical load is not exceeded. To increase the use of resources and save them. To increase the use of resources and save them.

Self-repair

Kubernetes restarts failed containers; replaces containers when nodes have died; kills containers which do not respond to status checks and does not disclose them to customers until they are ready to provide services.

Horizontal scaling

Scale the application by increasing or decreasing the cloud with simple commands, user interface or automatically based on the CPU load.

Discovering services and load balancing

You do not have to modify the application to use the service discovery mechanism. Kubernetes provides containers with its own IP addresses and a single DNS name for the container set and can balance the load between them.

Automation of implementation and removal

Kubernetes incrementally makes changes to the application or configuration while monitoring their status so as not to violate all instances at the same time. If something goes wrong, Kubernetes pulls back the change.

Confidential data and configuration management

Implement and update confidential information such as passwords or application configuration without rebuilding the image and without revealing that confidential information in the configuration.

Medium orchestration

Automatically mounts external memories choosing by user from local resources, from public cloud such as GCP and AWS, or network media such as NFS, iSCSI, Gluster, Ceph, Cinder, or Flocker.

Batch processing

Kubernetes can manage batch processing by replacing containers that have stopped working.

Kubernetes advantages

• Open source and free software
• Highly scalable
• Works with various PaaS systems, including GCE (Google Compute Engine), Microsoft Azure, Rackspace and vSphere, as well as operating systems such as Red Hat Atomic and CoreOS
• Based on Google’s many years of experience with containers in production
• Constant updates of microservices
• Makes task grouping easier thanks to labels which help identify objects by different characteristics

Kubernetes manages your application health, replication, load balancing and hardware resource allocation for you. The system was designed from the ground up to be resistant to damage and to cope in the event of a component failure, which is especially useful for companies using clusters.

Kubernetes disadvantages

• Some degree of reorganization is needed while using Kubernetes with an existing application
• Containers sometimes need to be manually started or restarted before they work according to specifications. This can happen in some situations, for example at almost full performance
• Uses a different configuration, YAML definition and API

Alternatives to Kubernetes

There are several other tools which also provide container arrangement options. The two largest players competing with Kubernetes are Docker Swarm and Mesosphere DC / OS. Docker Swarm is an easier-to-use option, which is a problem for Kubernetes, because it is criticized for being very complicated in implementation and management.

Mesosphere DC / OS is a container orchestrating system, designed for large data sets. It has been designed to set up containers along with other workloads such as machine learning and large data sets, and offers integration with related tools such as Apache Spark.

In general, Kubernetes is currently the most widely accepted and mature tool for arranging containers, as evidenced by the number of community contributors and the number of adaptations by enterprises. The key to K8S’ success was the ability to provide not only components for launching and monitoring containers, but also their efforts to create different sets of container use cases on their platform to cope with various types of advanced loads. For example, in Kubernetes we can find native objects, native units on the system that allow us to enablement a container or start a database. For other solutions, there is no distinction between containers in which have something that can be destroyed at any time.

A bright future for Kubernetes

Kubernetes’ development last year took place at the speed of light, the community became the real power of K8S. The future of Kubernetes is closely linked to the future of containers and microservices. Although it is possible to crossing to microservices without containers, the benefits are not so pronounced. Containers offer more precise runtime environments, better server utilization, and better load response which are less predictable, though solid container organization is needed to take full advantage of these benefits. Kubernetes facilitates the adoption of containers, providing a solid organization to run implementations with thousands of containers in production, which is crucial for the architecture of microservices.

Containers are quickly taking over the world of software development, and the momentum of Kubernetes is accelerating. He became the main container orchestrator thanks to his deep specialist knowledge, company adoption and reliable ecosystem. Through the growing number of collaborators and service providers, Kubernetes will continue to improve and expand its functionality, types of supported applications and integration with the superior ecosystem. The combination of these factors will further accelerate and streamline the use of containers and microservices to fundamentally change the way software is developed, implemented and improved. Moreover, with the maturation of container orchestrations and microservices, they will open the door to adopting new implementation standards, programming practices and business models.