Basics of affinity and antiaffinity in k8s cluster Affinity Node affinity is somewhat like an attachment based on the labels that a node has, Let us say we need to schedule pods on nodes that have certain labels, we use node affinity to tell pods to schedule itself to the…

Simplified taints and tolerations in k8s Taints Similar to labels but pods understand to avoid tainted nodes by default unless the pods have toleration towards it. Kind of like a repellent by default, unless there is some explicit toleration towards it. Tolerations The tolerations defined on pods make the pods tolerant to…

k8s svc and how to use them A kubernetes object. Provides abstraction over a set of running pods. clients can access using services which loadbalance the requests to the pods. endpoints: backend entities where services route traffic. each pod will be the endpoint of the service. Basic service definition apiVersion…

k8s network policies allows flow control to and from pods. isolates pods from traffic they do not require. pods are non isolated and open to all communication by default. Any network policy that selects pod will cause it to be isolated and abide the network policy rules. A networkPolicy can…

Rolling updates in kubernetes deployment Managed using deployments. Rolling update: allows deployment to use new updates without downtime via gradual replacement of old pods with new updated ones. Change can be anything in the pod template that is part of the deployment manifest. Rollback: If there is a problem in…

Scale your applications using deployments in kubernetes. Let us understand some of the important components and their use cases :- deployment defines a desired state for a replica set. deployment controller ensures the desired state by creating, deleting and replacing pods with new configs. replicas Specifies no of pod replicas…

A Guide to static pod with example. Static pods are created by the kubelet directly without any usage of kubernetes api. How do we do this ? This is due to a default path that kubelet uses, if you keep a manifest file the kubelet picks it up and applies it. path: /etc/kubernetes/manifests Example: kubectl run nginx-pod-2 --image nginx --dry-run=client -o yaml > /etc/kubernetes/manifests/nginx-pod-2.yaml

Basics of daemonsets in kubernetes Daemonset ensures that all the available worker nodes have a copy of a running pod defined within the DaemonSet. As new nodes are added the pods of daemonset are added to them. Daemonsets follow the regular scheduling rules and if the scheduling rules don’t allow pods to run on a particular node then the daemonset will respect scheduling rule and won’t assign pod to it.

assign your pods to the nodes of your choice. Scheduling: assigning pods to the nodes. scheduler manages the pods scheduling. Primarily resource requests and node resource availability is checked by the kubernetes scheduler before scheduling the pod. nodeSelector limit which node pods can be scheduled. uses node lables. example of node…