<p>I have a problem with one of the pods. It says that it is in a pending state.</p>

<p>If I describe the pod, this is what I can see:</p>

<pre><code>Events:
  Type     Reason             Age                From                Message
  ----     ------             ----               ----                -------
  Normal   NotTriggerScaleUp  1m (x58 over 11m)  cluster-autoscaler  pod didn't trigger scale-up (it wouldn't fit if a new node is added): 2 node(s) didn't match node selector
  Warning  FailedScheduling   1m (x34 over 11m)  default-scheduler   0/6 nodes are available: 6 node(s) didn't match node selector. 
</code></pre>

<p>If I check the logs, there is nothing in there (it just outputs empty value).</p>

<p>--- Update ---
This is my pod yaml file</p>

<pre><code>apiVersion: v1
kind: Pod
metadata:
  annotations:
    checksum/config: XXXXXXXXXXX
    checksum/dashboards-config: XXXXXXXXXXX
  creationTimestamp: 2020-02-11T10:15:15Z
  generateName: grafana-654667db5b-
  labels:
    app: grafana-grafana
    component: grafana
    pod-template-hash: "2102238616"
    release: grafana
  name: grafana-654667db5b-tnrlq
  namespace: monitoring
  ownerReferences:
  - apiVersion: apps/v1
    blockOwnerDeletion: true
    controller: true
    kind: ReplicaSet
    name: grafana-654667db5b
    uid: xxxx-xxxxx-xxxxxxxx-xxxxxxxx
  resourceVersion: "98843547"
  selfLink: /api/v1/namespaces/monitoring/pods/grafana-654667db5b-tnrlq
  uid: xxxx-xxxxx-xxxxxxxx-xxxxxxxx
spec:
  containers:
  - env:
    - name: GF_SECURITY_ADMIN_USER
      valueFrom:
        secretKeyRef:
          key: xxxx
          name: grafana
    - name: GF_SECURITY_ADMIN_PASSWORD
      valueFrom:
        secretKeyRef:
          key: xxxx
          name: grafana
    - name: GF_INSTALL_PLUGINS
      valueFrom:
        configMapKeyRef:
          key: grafana-install-plugins
          name: grafana-config
    image: grafana/grafana:5.0.4
    imagePullPolicy: Always
    name: grafana
    ports:
    - containerPort: 3000
      protocol: TCP
    readinessProbe:
      failureThreshold: 3
      httpGet:
        path: /api/health
        port: 3000
        scheme: HTTP
      initialDelaySeconds: 30
      periodSeconds: 10
      successThreshold: 1
      timeoutSeconds: 30
    resources:
      requests:
        cpu: 200m
        memory: 100Mi
    terminationMessagePath: /dev/termination-log
    terminationMessagePolicy: File
    volumeMounts:
    - mountPath: /etc/grafana
      name: config-volume
    - mountPath: /var/lib/grafana/dashboards
      name: dashboard-volume
    - mountPath: /var/lib/grafana
      name: storage-volume
    - mountPath: /var/run/secrets/kubernetes.io/serviceaccount
      name: default-token-tqb6j
      readOnly: true
  dnsPolicy: ClusterFirst
  initContainers:
  - command:
    - sh
    - -c
    - cp /tmp/config-volume-configmap/* /tmp/config-volume 2&gt;/dev/null || true; cp
      /tmp/dashboard-volume-configmap/* /tmp/dashboard-volume 2&gt;/dev/null || true
    image: busybox
    imagePullPolicy: Always
    name: copy-configs
    resources: {}
    terminationMessagePath: /dev/termination-log
    terminationMessagePolicy: File
    volumeMounts:
    - mountPath: /tmp/config-volume-configmap
      name: config-volume-configmap
    - mountPath: /tmp/dashboard-volume-configmap
      name: dashboard-volume-configmap
    - mountPath: /tmp/config-volume
      name: config-volume
    - mountPath: /tmp/dashboard-volume
      name: dashboard-volume
    - mountPath: /var/run/secrets/kubernetes.io/serviceaccount
      name: default-token-tqb6j
      readOnly: true
  nodeSelector:
    nodePool: cluster
  priority: 0
  restartPolicy: Always
  schedulerName: default-scheduler
  securityContext: {}
  serviceAccount: default
  serviceAccountName: default
  terminationGracePeriodSeconds: 300
  tolerations:
  - effect: NoExecute
    key: node.kubernetes.io/not-ready
    operator: Exists
    tolerationSeconds: 300
  - effect: NoExecute
    key: node.kubernetes.io/unreachable
    operator: Exists
    tolerationSeconds: 300
  volumes:
  - emptyDir: {}
    name: config-volume
  - emptyDir: {}
    name: dashboard-volume
  - configMap:
      defaultMode: 420
      name: grafana-config
    name: config-volume-configmap
  - configMap:
      defaultMode: 420
      name: grafana-dashs
    name: dashboard-volume-configmap
  - name: storage-volume
    persistentVolumeClaim:
      claimName: grafana
  - name: default-token-tqb6j
    secret:
      defaultMode: 420
      secretName: default-token-tqb6j
status:
  conditions:
  - lastProbeTime: 2020-02-11T10:45:37Z
    lastTransitionTime: 2020-02-11T10:15:15Z
    message: '0/6 nodes are available: 6 node(s) didn''t match node selector.'
    reason: Unschedulable
    status: "False"
    type: PodScheduled
  phase: Pending
  qosClass: Burstable
</code></pre>

<p>Do you know how should I further debug this?</p>

<p>Solution :  You can do one of the two things to allow scheduler to fullfil your pod creation request.</p>
<ol>
<li><p>you can choose to remove these lines from your pod yaml and start your pod creation again from scratch (if you need a selector for a reason go for approach as on next step 2)</p>
<pre><code>nodeSelector: 
    nodePool: cluster 
</code></pre>
</li>
</ol>
<p>or</p>
<ol start="2">
<li>You can ensure that you add this <code>nodePool: cluster</code> as label to all your nodes so the pod will be scheduled by using the available selector.</li>
</ol>
<p>You can use this command to label all nodes</p>
<p><code>kubectl label nodes &lt;your node name&gt; nodePool=cluster</code></p>
<p>Run above command by replacing node name from your cluster details for each node or only the nodes you want to be select with this label.</p>
