One of the questions in my CKA exam was how to display taints with kubectl. While you can use kubectl describe, it creates a lot of other information too.

Then I found out about jsonpath and it’s similarity to jq

You can display the taints with something like

for a in $(kubectl get nodes --no-headers | awk '{print $1}')
do
echo $a -- $(kubectl get nodes/$a -o jsonpath='{.spec.taints[*].key}{":"}{.spec.taints[*].effect}')
done

Sample output

ip-10-10-10-147.eu-west-2.compute.internal -- node-role.kubernetes.io/master:NoSchedule
ip-10-10-10-159.eu-west-2.compute.internal -- :

So the first one has a taint (it’s the master node) and the second one doesn’t.
(maybe I need to hack this a bit more when I have multiple taints but I’ll do that when I have some multi-tainted nodes to play with)

EDIT: Another way as provided by tdodds81

$ kubectl get nodes -o=custom-columns=NAME:.metadata.name,TAINTS:.spec.taints
NAME TAINTS
ip-10-10-10-148.eu-west-2.compute.internal [map[effect:NoSchedule key:node-role.kubernetes.io/master]]
ip-10-10-10-218.eu-west-2.compute.internal
ip-10-10-10-239.eu-west-2.compute.internal
ip-10-10-10-249.eu-west-2.compute.internal
ip-10-10-10-51.eu-west-2.compute.internal

And with multi-taints, it looks like this (on a GKE cluster)

$ kubectl get nodes -o custom-columns=NAME:.metadata.name,TAINTS:.spec.taints
NAME                                                  TAINTS
gke-test-cluster-k8s-n1-highmem-2-nod-589548dd-3z1v   [map[effect:NoSchedule key:key1 timeAdded:<nil> value:value1] map[value:value2 effect:NoSchedule key:key2 timeAdded:<nil>]]
gke-test-cluster-k8s-n1-highmem-2-nod-7a33f13b-9lwk   <none>
gke-test-cluster-k8s-n1-highmem-2-nod-7a33f13b-lnvl   <none>
gke-test-cluster-k8s-n1-highmem-2-nod-7a33f13b-nt49   <none>
gke-test-cluster-k8s-n1-highmem-2-nod-7a33f13b-xgbd   <none>