Kubectl extension to spawn a shell on a k8s node

kubectl-shell

#!/bin/bash -eu
# This script starts a new pod with a privileged container to run admin commands
if [ "$#" -ne 1 ]; then
    echo "usage: $0 nodeName" >&2
    exit 1
fi
node=${1:?}
nodeName=$(kubectl get node ${node} -o template --template='{{index .metadata.labels "kubernetes.io/hostname"}}')
podName=${USER:-unknown}-shell-${nodeName}
exec kubectl run ${podName:?} --restart=Never -it --rm --image overriden --overrides '
{
  "spec": {
    "priorityClassName": "system-node-critical",
    "hostPID": true,
    "hostNetwork": true,
    "nodeSelector": { "kubernetes.io/hostname": "'${nodeName:?}'" },
    "tolerations": [{
        "operator": "Exists"
    }],
    "containers": [
      {
        "name": "nsenter",
        "image": "ubuntu:latest",
        "command": [
          "nsenter", "--all", "--target=1", "--", "su", "-"
        ],
        "stdin": true,
        "tty": true,
        "securityContext": {
          "privileged": true
        }
      }
    ]
  }
}' --attach "$@"