11-TAINT AND TOLERANCE

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TAINT AND TOLERANCE-

If tainit is applied then pods which dont have tolerence to that node will not be launched on that node

by default all pods dont have any tolerence to any taint

taint- taint is added to node

command to taint a node - kubectl taint nodes <node name> key=value:<taint-effect>
there are 3 taint effects -NoSchedule  | PreferNoSchedule | NoExecute
command to remove a taint - kubectl taint node <node name> <key>-

NoSchedule - pods will not be scheduled on the node
PreferNoSchedule - pods will not be scheduled on the node but no garuntee
NoExecute- now new pods will not be schedukled and if alredy existing pods cant tolerate the taint then they will be evicted.

toleration - toleration is added to pod
example yaml of pod with toleration - cat > pod-definition.yaml

apiVersion: v1
kind: Pod
metadata:
   name: myapp-pod (this is name of pod)
   labels:
      app: myapp
      anykey: anyvalue
      costcenter: US
      
      
spec:
   containers:
      - name: nginx-container (this is name of container in pod)
        image: nginx (this is the image that kubernetes gets from docker hub)
   tolerations:
      - key: "<key>"
	    operator: "Equal"
		value: "<value>"
		effect: "NoSchedule"
		
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