<p>My ingress pod is having trouble reaching two clusterIP services by IP. There are plenty of other clusterIP services it has no trouble reaching. Including in the same namespace. Another pod has no problem reaching the service (I tried the default backend in the same namespace and it was fine).</p>

<p>Where should I look? Here are my actual services, it cannot reach the first but can reach the second:</p>

<pre><code>- apiVersion: v1
  kind: Service
  metadata:
    creationTimestamp: "2019-08-23T16:59:10Z"
    labels:
      app: pka-168-emtpy-id
      app.kubernetes.io/instance: palletman-pka-168-emtpy-id
      app.kubernetes.io/managed-by: Tiller
      helm.sh/chart: pal-0.0.1
      release: palletman-pka-168-emtpy-id
    name: pka-168-emtpy-id
    namespace: palletman
    resourceVersion: "108574168"
    selfLink: /api/v1/namespaces/palletman/services/pka-168-emtpy-id
    uid: 539364f9-c5c7-11e9-8699-0af40ce7ce3a
  spec:
    clusterIP: 100.65.111.47
    ports:
    - port: 80
      protocol: TCP
      targetPort: 8080
    selector:
      app: pka-168-emtpy-id
    sessionAffinity: None
    type: ClusterIP
  status:
    loadBalancer: {}
- apiVersion: v1
  kind: Service
  metadata:
    creationTimestamp: "2019-03-05T19:57:26Z"
    labels:
      app: production
      app.kubernetes.io/instance: palletman
      app.kubernetes.io/managed-by: Tiller
      helm.sh/chart: pal-0.0.1
      release: palletman
    name: production
    namespace: palletman
    resourceVersion: "81337664"
    selfLink: /api/v1/namespaces/palletman/services/production
    uid: e671c5e0-3f80-11e9-a1fc-0af40ce7ce3a
  spec:
    clusterIP: 100.65.82.246
    ports:
    - port: 80
      protocol: TCP
      targetPort: 8080
    selector:
      app: production
    sessionAffinity: None
    type: ClusterIP
  status:
    loadBalancer: {}
</code></pre>

<p>My ingress pod:</p>

<pre><code>apiVersion: v1
kind: Pod
metadata:
  annotations:
    sumologic.com/format: text
    sumologic.com/sourceCategory: 103308/CT/LI/kube_ingress
    sumologic.com/sourceName: kube_ingress
  creationTimestamp: "2019-08-21T19:34:48Z"
  generateName: ingress-nginx-65877649c7-
  labels:
    app: ingress-nginx
    k8s-addon: ingress-nginx.addons.k8s.io
    pod-template-hash: "2143320573"
  name: ingress-nginx-65877649c7-5npmp
  namespace: kube-ingress
  ownerReferences:
  - apiVersion: extensions/v1beta1
    blockOwnerDeletion: true
    controller: true
    kind: ReplicaSet
    name: ingress-nginx-65877649c7
    uid: 97db28a9-c43f-11e9-920a-0af40ce7ce3a
  resourceVersion: "108278133"
  selfLink: /api/v1/namespaces/kube-ingress/pods/ingress-nginx-65877649c7-5npmp
  uid: bcd92d96-c44a-11e9-8699-0af40ce7ce3a
spec:
  containers:
  - args:
    - /nginx-ingress-controller
    - --default-backend-service=$(POD_NAMESPACE)/nginx-default-backend
    - --configmap=$(POD_NAMESPACE)/ingress-nginx
    - --publish-service=$(POD_NAMESPACE)/ingress-nginx
    env:
    - name: POD_NAME
      valueFrom:
        fieldRef:
          apiVersion: v1
          fieldPath: metadata.name
    - name: POD_NAMESPACE
      valueFrom:
        fieldRef:
          apiVersion: v1
          fieldPath: metadata.namespace
    image: gcr.io/google_containers/nginx-ingress-controller:0.9.0-beta.13
    imagePullPolicy: Always
    livenessProbe:
      failureThreshold: 3
      httpGet:
        path: /healthz
        port: 10254
        scheme: HTTP
      initialDelaySeconds: 30
      periodSeconds: 10
      successThreshold: 1
      timeoutSeconds: 5
    name: ingress-nginx
    ports:
    - containerPort: 80
      name: http
      protocol: TCP
    resources: {}
    terminationMessagePath: /dev/termination-log
    terminationMessagePolicy: File
    volumeMounts:
    - mountPath: /var/run/secrets/kubernetes.io/serviceaccount
      name: default-token-dg5wn
      readOnly: true
  dnsPolicy: ClusterFirst
  nodeName: ip-10-55-131-177.eu-west-1.compute.internal
  restartPolicy: Always
  schedulerName: default-scheduler
  securityContext: {}
  serviceAccount: default
  serviceAccountName: default
  terminationGracePeriodSeconds: 60
  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:
  - name: default-token-dg5wn
    secret:
      defaultMode: 420
      secretName: default-token-dg5wn
status:
  conditions:
  - lastProbeTime: null
    lastTransitionTime: "2019-08-21T19:34:48Z"
    status: "True"
    type: Initialized
  - lastProbeTime: null
    lastTransitionTime: "2019-08-21T19:34:50Z"
    status: "True"
    type: Ready
  - lastProbeTime: null
    lastTransitionTime: "2019-08-21T19:34:48Z"
    status: "True"
    type: PodScheduled
  containerStatuses:
  - containerID: docker://d597673f4f38392a52e9537e6dd2473438c62c2362a30e3d58bf8a98e177eb12
    image: gcr.io/google_containers/nginx-ingress-controller:0.9.0-beta.13
    imageID: docker-pullable://gcr.io/google_containers/nginx-ingress-controller@sha256:c9d2e67f8096d22564a6507794e1a591fbcb6461338fc655a015d76a06e8dbaa
    lastState: {}
    name: ingress-nginx
    ready: true
    restartCount: 0
    state:
      running:
        startedAt: "2019-08-21T19:34:50Z"
  hostIP: 10.55.131.177
  phase: Running
  podIP: 172.6.218.18
  qosClass: BestEffort
  startTime: "2019-08-21T19:34:48Z"
</code></pre>

Lev Kuznetsov
<p>It could be connectivity to the node where your Pod is running. (Or network overlay related) You can check where that pod is running:</p>

<pre><code>$ kubectl get pod -o=json  | jq .items[0].spec.nodeName
</code></pre>

<p>Check if the node is 'Ready':</p>

<pre><code>$ kubectl get node &lt;node-from-above&gt;
</code></pre>

<p>If it's ready, then ssh into the node to further troubleshoot:</p>

<pre><code>$ ssh &lt;node-from-above&gt;
</code></pre>

<p>Is your overlay pod running on the node? (Calico, Weave, CNI, etc)</p>

<p>You can further troubleshoot connecting to the pod/container</p>

<pre><code># From &lt;node-from-above&gt;
$ docker exec -it &lt;container-id-in-pod&gt; bash
# Check connectivity (ping, dig, curl, etc)
</code></pre>

<p>Also, from using the kubectl command line (if you have network connectivity to the node)</p>

<pre><code>$ kubectl exec -it &lt;pod-id&gt; -c &lt;container-name&gt; bash 
# Troubleshoot...
</code></pre>
