title: Auto-provisioned node pool is not getting cleaned up
body: <p>I have a Kubernetes cluster with auto-provisioning enabled on GKE.</p>
  
  <pre><code>gcloud beta container clusters create "some-name" --zone "us-central1-a" \
    --no-enable-basic-auth --cluster-version "1.13.11-gke.14" \
    --machine-type "n1-standard-1" --image-type "COS" \
    --disk-type "pd-standard" --disk-size "100" \
    --metadata disable-legacy-endpoints=true \
    --scopes "https://www.googleapis.com/auth/devstorage.read_only","https://www.googleapis.com/auth/logging.write","https://www.googleapis.com/auth/monitoring","https://www.googleapis.com/auth/servicecontrol","https://www.googleapis.com/auth/service.management.readonly","https://www.googleapis.com/auth/trace.append" \
    --num-nodes "1" --enable-stackdriver-kubernetes --enable-ip-alias \
    --network "projects/default-project/global/networks/default" \
    --subnetwork "projects/default-project/regions/us-central1/subnetworks/default" \
    --default-max-pods-per-node "110" \
    --enable-autoscaling --min-nodes "0" --max-nodes "8" \
    --addons HorizontalPodAutoscaling,KubernetesDashboard \
    --enable-autoupgrade --enable-autorepair \
    --enable-autoprovisioning --min-cpu 1 --max-cpu 40 --min-memory 1 --max-memory 64
  </code></pre>
  
  <p>I ran a deployment which wouldn't fit on the existing node (which has 1 CPU).</p>
  
  <pre><code>kubectl run say-lol --image ubuntu:18.04 --requests cpu=4 -- bash -c 'echo lolol &amp;&amp; sleep 30'
  </code></pre>
  
  <p>The auto-provisioner correctly detected that a new node pool was needed, and it created a new cluster and started running the new deployment. <strong>However, it was not able to delete it after it was no longer needed.</strong></p>
  
  <pre><code>kubectl delete deployment say-lol
  </code></pre>
  
  <p>After all pods are gone, the new cluster has been sitting idle for more than 20 hours.</p>
  
  <pre><code>$ kubectl get nodes
  NAME                                                  STATUS   ROLES    AGE   VERSION
  gke-some-name-default-pool-5003d6ff-pd1p        Ready    &lt;none&gt;   21h   v1.13.11-gke.14
  gke-some-name-nap-n1-highcpu-8--585d94be-vbxw   Ready    &lt;none&gt;   21h   v1.13.11-gke.14
  
  $ kubectl get deployments
  No resources found in default namespace.
  
  $ kubectl get events
  No resources found in default namespace.
  </code></pre>
  
  <p>Why isn't it cleaning up the expensive node pool?</p>