DevOps with Kubernetes - Second Edition

Resource types and allocations

There are two core resource types that participate in the scheduling process, namely CPU and memory. To see the capability of a node, we can check its .status.allocatable path:

# Here we only show the path with a go template.$ kubectl get node <node_name> -o go-template --template=\'{{range $k,$v:=.status.allocatable}}{{printf "%s: %s\n" $k $v}}{{end}}'cpu: 2ephemeral-storage: 14796951528hugepages-2Mi: 0memory: 1936300Kipods: 110

As we can see, these resources will be allocated to any pod in need by the scheduler. But how does the scheduler know how many resources a pod will consume? We actually have to instruct Kubernetes about the request and the limit for each pod. The syntax is spec.containers[].resources.{limits,requests}.{resource_name} ...