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Volume management in Kubernetes
Since pods created in k8s are ephemeral, we are able to get the data as long as pods are alive, but if pods are terminated data stored in it completely lost and it cannot get back, for that we need to mount a volume to write the data into that of a pod. To do…
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Quick Understanding on Stateful Sets in Kubernetes
Stateful sets are similar to deployments, they can scale up and scale down, they can perform rolling updates etc. All most it performs similar functions like replica sets and deployment sets. but there some difference as well, in stateful sets pods are created in a sequential order, that means when the pods are deployed, 1st…
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HOW TO DO BACKUP AND RESTORE ENTIRE K8S CLUSTER?
If you have deployed different applications on k8s cluster using various objects like deployments, pods, services etc. all the info about cluster is stored into ETCD cluster. If your application is using persistent storage that will be considered as another backup scenario. We will be creating different resources either using imperative way or declarative way.…
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How to do Installation of K8S using kubeadm?
Till now I have given blogs on k8s objects, services, namespaces, ingress etc. but where to execute and implement all those, yes, we need a k8s cluster for that, if you have it already go n execute, if not, here is the solution for you. Execute below commands to configure the master node “(# are…
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NODE AFFINITY
The k8s node affinity feature is to ensure pods are hosted on a particular node. As mentioned in previous blog large data processing nodes are into node-1. we achieved that using node selectors. As I mentioned that we cannot provide advance expressions like large or medium / not in small nodes. Node affinity feature provides…
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Node Selector
Assume you have 3 nodes cluster of which two of them are having lower hardware resources and one of them is larger node configured with higher resources, and there are different kinds of workloads running in our cluster, and you would like to dedicate data-processing workloads that require higher horse power to the larger nodes…
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Taints and Tolerations
Taints and tolerations are used to restrict the pods to schedule them onto respective nodes. There is nothing to do with security. If no restrictions are applied K8s scheduler places the pods in all respective nodes equally to balance all the pods Assume we have certain resources assigned for application in a particular node, and…
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What is ingress and what are the components of it?
Ingress is a resource, which exposes the http and https from external sources to the services within the cluster, by adding the rules in the ingress resource for routing the traffic, where traffic is controlled by ingress controller. From the above lines we can understand that ingress consists of two components: Ingress resource Ingress controller…
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Kubernetes RBAC (Role Based Access Control)
The Kubernetes RBAC (role bases access control) system helps us in defining set of rules in controlling the access among users across resources. Kubernetes cluster by default has two name spaces, “default” and “kube-system”. Creation of additional namespaces is also possible for organizing and separation of work based on our purpose which I have already…
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Namespaces in Kubernetes
A default namespace is created automatically when the cluster is being setup. To isolate or prevent a user from accidentally deleting the services, Kubernetes creates certain pods for its internal purpose like networking solution, DNS service etc. Kubernetes creates them under another namespace which is created at cluster startup named kube-system. The third namespace that…