Kubernetes is an open-source container orchestration platform for managing and scaling business applications. It allows you to deploy and manage microservices that make up the technology stack as an orchestration tool. It ensures both portability and scalability while deploying container-based applications across cloud environments. It improves the overall speed and ease of application deployment in Azure whilst ensuring lower application downtime and cost-effectiveness. Azure Kubernetes services incorporate resource utility-based load balancing, track allocated resources, and are also capable of auto-scaling resources based on demands. Based on the health of individual resources, Azure Kubernetes can enable self-healing of applications by automatically restarting and replicating them to use in new containers.
Azure Kubernetes Service (AKS) streamlines
the deployment and management of the Kubernetes clusters in Azure. AKS reduces
the complexity and operational overhead by offloading the responsibility of
resource allocation and security to Azure. AKS is a free container service
where you need to pay only for cloud resources. Some of the core features of Azure
Kubernetes services are:
●
Flexible
deployment
●
Identity
and Security management
●
Integrated
logging and Monitoring
●
Cluster
node scaling and Updates
●
HTTP
application routing
●
GPU-enabled
nodes
Why
do we need Kubernetes?
Kubernetes integrates natively with
Microsoft Azure’s cloud serverless DevOps offerings and its continuous
integration and deployment experience.
●
Provides
container communication
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Appropriate
container deployment using DevOps
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Facilitates
careful container management and self-healing
●
Enables
autoscaling and intelligent scheduling
Kubernetes Architecture
Kubernetes constitute two different layers,
one being the Kubernetes master and the other being the worker nodes. The
Kubernetes master is responsible for scheduling, provisioning, controlling, and
exposing the API to the clients through the user interface or the command-line
interface. Kubernetes understands declarative artifacts, defined using YAML,
and submitted to the master. Depending on the constraints and rules, the
Kubernetes master will schedule the pods or the artifacts submitted in one of
the nodes. Here, the master is responsible for front-ending the operations, and
the nodes that participate in the distributed computing form a cluster. The
registry plays a vital role in storing the docker images in the private or
public registries, like the docker hub or google container registry running
within the data center. Visit us for Azure Cost and Subscription Monitoring Tool
Kubernetes Master
The Kubernetes master runs the scheduler,
controller, and API server, delivering high-level cluster management. An API
server is responsible for exposing various API for every operation. Kubernetes
is API-centered. Kubernetes provides a powerful command-line tool called cube
CTL. This Go language application is compiled into binary and communicates with
the API server. Kubernetes comes with an add-on called the ‘Kubernetes
dashboard.' The scheduler is responsible for physically scheduling the
artifacts, containers, or pods across multiple nodes. Depending on the
constraints, the scheduler will look for the appropriate nodes that meet the
criteria and schedule the pods appropriately. The controller is responsible for
proper coordination and health of the entire cluster, ensuring the precise
functioning of pods and nodes. It facilitates adequate configuration
maintenance. ‘Etcd’ is a distributed key-value database developed by the core
OS. At any point in time, the component of Kubernetes can query the XD for
understanding the state of the cluster. UnifyCloud's Cloud Migration Tool
Kubernetes
Nodes
The nodes in the Kubernetes contain Kube-proxy, the core networking component of Kubernetes, which is responsible for maintaining network configuration. It manipulates IP tables on each host to make the network configuration intact. In addition, it supports network distribution across all the nodes, pods, and containers. It effectively maintains communication across all the elements of the cluster.
This node will run the docker responsible
for running the containers. The ‘kubelet’ is the agent responsible for
communicating the API with the cluster master. The nodes will communicate
metrics, health, and the present state of the nodes to XD and to the Kubernetes
master. The ‘kubelet’ and docker get packed into the supervisory ‘D’ layer, a
process manager. ‘Fluentd’ is another component that manages logs and
communicates with the locking mechanism.
The nodes are responsible for running
multiple pods of different configurations. In addition, the Kubernetes nodes
also run add-ons such as DNS and UI.
AKS
Networking
To allow access to the application or for application components to communicate, Kubernetes provides an abstraction layer to virtual networking. Kubernetes nodes connect to the virtual network and provide inbound and outbound connectivity for pods. The Kube-proxy component runs on every node to provide these extensive network features.
The cluster IP generates an internal IP
address to use within the AKS cluster and serves for internal-only applications
that support other workloads within the cluster. The node port creates a port
mapping on the underlying node that allows the application to be accessed
directly within the node IP address and the port. Finally, the Load balancer
creates an Azure load balancer resource that configures an external IP address,
connects the requested pods to the load balancing backend pool, allows customer
traffic to reach the application, and creates load-balancing rules on the
desired ports. Navigate here for knowing more about CloudAtlas Migration and Assessment Platform
AKS
Storage
Applications in Azure Kubernetes services
may need to store and retrieve data for some application workloads. For
temporary storage, this collecting of data locally uses the fast cache
mechanism of the respective nodes. However, specific application workloads such
as rescheduling the pods on different nodes may require storage that persists
on regular data volumes within the Azure platform. Multiple pods need to share
the same data or reattached data volumes in such cases. Finally, sensitive data
or application configuration information are saved directly into the pods.
These storage resources, such as volume, persistent volume, storage classes,
and persistent volume claims, are created and managed by the Kubernetes API.
AKS Security
Azure runs workloads in the Azure
Kubernetes services to protect your customer data. Therefore, securing your
cluster is the primary concern for Azure. Kubernetes comprises security
components such as network policies that control the traffic between pods and
endpoints and facilitate secrets to store sensitive data. In addition, Azure
adds elements such as network security groups and orchestrations for upgrading
the cluster. These security components get merged and keep the AKS cluster
running on the latest OS security upgrades and Kubernetes releases. As a
result, AKS provides security for accessing credentials and ensures safe
network traffic.
In AKS, the Kubernetes master components
are part of the managed services provided by Microsoft. Each AKS cluster has
its own dedicated Kubernetes master that provides the API server scheduler.
Microsoft ultimately maintains this master. AKS nodes are Azure virtual
machines that one maintains and manages. The nodes are automatically deployed
with the latest operating system, security, and configuration upgrades when an
AKS cluster is created or scaled up.
AKS
and Azure Active Directory
You can use AKS and integrate with the Azure active directory. You can enhance the security of the AKS cluster by integrating the Azure active directory built on decades of Azure identity management. Azure AD is a cross-functional cloud-based directory and identity management service that combines complete directory services, application access management, and identity protection. With Azure AD, you can integrate on-premises identities into the AKS cluster to provide a single secure source of account management. In addition, in combination with Azure ID, AKS clusters can grant users or groups access to Kubernetes resources within a namespace or across the cluster.
AKS
Scaling
AKS
Scaling to Azure Container Instance (ACI)
If you need to scale your AKS cluster
rapidly, you can integrate with Azure container instances or ACI. Kubernetes
has built-in components for scaling down the replica and node count. However,
the horizontal pod auto scaler may schedule more pods if your application needs
to be rapidly scaled; this is because it gets provisioned by the existing
compute resources in the node pool. Azure container instances let one quickly
deploy container instances without additional infrastructure overheads. When
connecting with AKS, ACI becomes a secured, logical extension of your AKS
cluster. Your application requires no modification to use these nodes.
Virtual
‘Kubelet’
Virtual ‘kubelet’ is an open-source Kubernetes ‘kubelet’ implementation. Virtual Kubernetes is used to back up the Kubernetes clusters services such as container instances and Azure batch. These services then host application nodes on behalf of the Kubernetes cluster. The virtual ‘kubelet’ registers itself as a node and allows developers to deploy unlimited pods and containers with serverless and stateless applications. Visit us for cloud consulting services
Azure
Kubernetes Service- Use Cases
Ease
of Migration: You can easily migrate from the
existing applications to containers using Azure Kubernetes services. It
controls the network access through the Azure active directory integration and
Azure database using Open Service Broker for Azure.
Configuration
and Management of Microservices: AKS
simplifies the management and development of microservice-based applications
and offers load-balancing, scaling, and self-healing.
Elastic
Provisioning: AKS offers the simplicity of
managing Kubernetes services in the cloud with flexible provisioning and
eliminates the need to control the deployment infrastructure.
DevOps
Security: Azure offers a stable platform for enhanced
security when using Kubernetes and DevOps services. It improves the runtime,
integration, and delivery with dynamic policies.
Data
Streamlining: Azure Kubernetes services process
real-time data streaming with data point sensing for improved analysis.
Virtual
Node Scaling: AKS virtual node provisions the pods
inside the container interface and initiates the run time; if the AKS cluster
runs out of resources, additional pods are assigned automatically without
involving servers.
References
●
n.d. Microsoft Azure: Cloud
Computing Services. Accessed May 30, 2022. https://azure.microsoft.com.
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n.d. NetApp Cloud Solutions | Optimized
Storage In Any Cloud. Accessed May 30, 2022. https://cloud.netapp.com.
●
n.d. GitHub: Where the world
builds software · GitHub. Accessed May 30, 2022. https://github.com.
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