Kubernetes architecture

Kubernetes architecture

• 1.
  Kubernetes Architecture Janakiram MSV Analyst| Advisor | Architect Janakiram & Associates Google Developer Expert
• 2.
  Announcing The Kubernetes WebinarSeries ● Monthly webinar focused on helping you get started with Kubernetes ● Delivered by the experts from the container ecosystem ● Each webinar introduces a concept to accelerate your learning ● No specific prerequisites ○ Basic understanding of Docker will help ● All attendees will get $100 Google Cloud Platform Credits ● Win free annual and monthly subscriptions of MAPT eBook library ● The recording of this webinar will be available at Kubernetes.live
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  Objectives ● A closerlook at Kubernetes cluster ● Master components ● Node components ● Pods ● Labels & Selectors ● Replication Controllers ● Services
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  Kubernetes Architecture Kubernetes Master Node 1API UI CLI Node2 Node n Node 3 Registry
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  Kubernetes Master API ServerScheduler Controller etcd API UI CLI
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  Kubernetes Node kube-proxy Docker kubelet Supervisord fluentd PodPod Pod Pod Pod Pod Pod Pod Kubernetes Master AddonsDNSUI
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  A Simple ContainerizedApplication Python Web App Redis Database Client
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  Kubernetes Pod ● Groupof one or more containers that are always co-located, co-scheduled, and run in a shared context ● Containers in the same pod have the same hostname ● Each pod is isolated by ○ Process ID (PID) namespace ○ Network namespace ○ Interprocess Communication (IPC) namespace ○ Unix Time Sharing (UTS) namespace ● Alternative to a VM with multiple processes
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  Labels & Selectors ●Key/value pairs associated with Kubernetes objects ● Used to organize and select subsets of objects ● Attached to objects at creation time but modified at any time. ● Labels are the essential glue to associate one API object with other ○ Replication Controller -> Pods ○ Service -> Pods ○ Pods -> Nodes
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  Deploying a Pod PodDefinition Master kube-p roxyDocker kubelet Supervisord fluentd Web Pod Node DB Pod Pod Definition Python Redis
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  Services ● An abstractionto define a logical set of Pods bound by a policy by to access them ● Services are exposed through internal and external endpoints ● Services can also point to non-Kubernetes endpoints through a Virtual-IP-Bridge ● Supports TCP and UDP ● Interfaces with kube-proxy to manipulate iptables ● Service can be exposed internal or external to the cluster
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  Exposing Services DB PodWeb Pod 2 Web Pod 1 Web Pod 3 ClientNode Port Cluster IP
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  Demo Creating Pods &Services Python Web App & Redis DB
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  Replication Controller ● Ensuresthat a Pod or homogeneous set of Pods are always up and available ● Always maintains desired number of Pods ○ If there are excess Pods, they get killed ○ New pods are launched when they fail, get deleted, or terminated ● Creating a replication controller with a count of 1 ensures that a Pod is always available ● Replication Controller and Pods are associated through Labels
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  kube-p roxyDocker kubelet Supervisord fluentd Web Pod 1 Scaling Podswith Replication Controller RC Definition Master Node Web Pod 2 Web Pod 3 3 DB Pod
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  Demo Scaling Pods withReplication Controller
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  Summary ● Kubernetes Masterruns the API, Scheduler and Controller services ● Each Node is responsible for running one or more Pods ● Pods are the unit of deployment in Kubernetes ● Labels associate one Kubernetes object with the other ● Replication Controller ensures high availability of Pods ● Services expose Pods to internal and external consumers
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  Upcoming Webinar A CloserLook at Kubernetes Pods 9 AM PST, 26th October This session will discuss the best practices of creating, deploying, and managing Pods. We will take a closer look at the storage and networking architecture of containers running in the same Pod. Register at kubernetes.live for the upcoming webinars
• 19.
  Thank You! Send yourFeedback / Questions / Comments info@kubernetes.live