<p>I have a pod running and want to port forward so i can access the pod from the internal network.
I don't know what port it is listening on though, there is no service yet.</p>

<p>I describe the pod:</p>

<pre><code>$ kubectl describe pod queue-l7wck 
Name:         queue-l7wck
Namespace:    default
Priority:     0
Node:         minikube/192.168.64.3
Start Time:   Wed, 18 Dec 2019 05:13:56 +0200
Labels:       app=work-queue
              chapter=jobs
              component=queue
Annotations:  &lt;none&gt;
Status:       Running
IP:           172.17.0.2
IPs:
  IP:           172.17.0.2
Controlled By:  ReplicaSet/queue
Containers:
  queue:
    Container ID:   docker://13780475170fa2c0d8e616ba1a3b1554d31f404cc0a597877e790cbf01838e63
    Image:          gcr.io/kuar-demo/kuard-amd64:blue
    Image ID:       docker-pullable://gcr.io/kuar-demo/kuard-amd64@sha256:1ecc9fb2c871302fdb57a25e0c076311b7b352b0a9246d442940ca8fb4efe229
    Port:           &lt;none&gt;
    Host Port:      &lt;none&gt;
    State:          Running
      Started:      Wed, 18 Dec 2019 05:14:02 +0200
    Ready:          True
    Restart Count:  0
    Environment:    &lt;none&gt;
    Mounts:
      /var/run/secrets/kubernetes.io/serviceaccount from default-token-mbn5b (ro)
Conditions:
  Type              Status
  Initialized       True 
  Ready             True 
  ContainersReady   True 
  PodScheduled      True 
Volumes:
  default-token-mbn5b:
    Type:        Secret (a volume populated by a Secret)
    SecretName:  default-token-mbn5b
    Optional:    false
QoS Class:       BestEffort
Node-Selectors:  &lt;none&gt;
Tolerations:     node.kubernetes.io/not-ready:NoExecute for 300s
                 node.kubernetes.io/unreachable:NoExecute for 300s
Events:
  Type    Reason     Age        From               Message
  ----    ------     ----       ----               -------
  Normal  Scheduled  &lt;unknown&gt;  default-scheduler  Successfully assigned default/queue-l7wck to minikube
  Normal  Pulling    31h        kubelet, minikube  Pulling image "gcr.io/kuar-demo/kuard-amd64:blue"
  Normal  Pulled     31h        kubelet, minikube  Successfully pulled image "gcr.io/kuar-demo/kuard-amd64:blue"
  Normal  Created    31h        kubelet, minikube  Created container queue
  Normal  Started    31h        kubelet, minikube  Started container queue
</code></pre>

<p>even the JSON has nothing:</p>

<pre><code>$ kubectl get pods queue-l7wck -o json
{
    "apiVersion": "v1",
    "kind": "Pod",
    "metadata": {
        "creationTimestamp": "2019-12-18T03:13:56Z",
        "generateName": "queue-",
        "labels": {
            "app": "work-queue",
            "chapter": "jobs",
            "component": "queue"
        },
        "name": "queue-l7wck",
        "namespace": "default",
        "ownerReferences": [
            {
                "apiVersion": "apps/v1",
                "blockOwnerDeletion": true,
                "controller": true,
                "kind": "ReplicaSet",
                "name": "queue",
                "uid": "a9ec07f7-07a3-4462-9ac4-a72226f54556"
            }
        ],
        "resourceVersion": "375402",
        "selfLink": "/api/v1/namespaces/default/pods/queue-l7wck",
        "uid": "af43027d-8377-4227-b366-bcd4940b8709"
    },
    "spec": {
        "containers": [
            {
                "image": "gcr.io/kuar-demo/kuard-amd64:blue",
                "imagePullPolicy": "Always",
                "name": "queue",
                "resources": {},
                "terminationMessagePath": "/dev/termination-log",
                "terminationMessagePolicy": "File",
                "volumeMounts": [
                    {
                        "mountPath": "/var/run/secrets/kubernetes.io/serviceaccount",
                        "name": "default-token-mbn5b",
                        "readOnly": true
                    }
                ]
            }
        ],
        "dnsPolicy": "ClusterFirst",
        "enableServiceLinks": true,
        "nodeName": "minikube",
        "priority": 0,
        "restartPolicy": "Always",
        "schedulerName": "default-scheduler",
        "securityContext": {},
        "serviceAccount": "default",
        "serviceAccountName": "default",
        "terminationGracePeriodSeconds": 30,
        "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-mbn5b",
                "secret": {
                    "defaultMode": 420,
                    "secretName": "default-token-mbn5b"
                }
            }
        ]
    },
    "status": {
        "conditions": [
            {
                "lastProbeTime": null,
                "lastTransitionTime": "2019-12-18T03:13:56Z",
                "status": "True",
                "type": "Initialized"
            },
            {
                "lastProbeTime": null,
                "lastTransitionTime": "2019-12-18T03:14:02Z",
                "status": "True",
                "type": "Ready"
            },
            {
                "lastProbeTime": null,
                "lastTransitionTime": "2019-12-18T03:14:02Z",
                "status": "True",
                "type": "ContainersReady"
            },
            {
                "lastProbeTime": null,
                "lastTransitionTime": "2019-12-18T03:13:56Z",
                "status": "True",
                "type": "PodScheduled"
            }
        ],
        "containerStatuses": [
            {
                "containerID": "docker://13780475170fa2c0d8e616ba1a3b1554d31f404cc0a597877e790cbf01838e63",
                "image": "gcr.io/kuar-demo/kuard-amd64:blue",
                "imageID": "docker-pullable://gcr.io/kuar-demo/kuard-amd64@sha256:1ecc9fb2c871302fdb57a25e0c076311b7b352b0a9246d442940ca8fb4efe229",
                "lastState": {},
                "name": "queue",
                "ready": true,
                "restartCount": 0,
                "started": true,
                "state": {
                    "running": {
                        "startedAt": "2019-12-18T03:14:02Z"
                    }
                }
            }
        ],
        "hostIP": "192.168.64.3",
        "phase": "Running",
        "podIP": "172.17.0.2",
        "podIPs": [
            {
                "ip": "172.17.0.2"
            }
        ],
        "qosClass": "BestEffort",
        "startTime": "2019-12-18T03:13:56Z"
    }
}
</code></pre>

<p>How do you checker what port a pod is listening on with kubectl?</p>

<p><strong>Update</strong></p>

<p>If I ssh into the pod and run <code>netstat -tulpn</code> as suggested in the comments I get:</p>

<pre><code>$ kubectl exec -it queue-pfmq2 -- sh
~ $ netstat -tulpn
Active Internet connections (only servers)
Proto Recv-Q Send-Q Local Address           Foreign Address         State       PID/Program name    
tcp        0      0 :::8080                 :::*                    LISTEN      1/kuard
</code></pre>

<p>But this method is not using <code>kubectl</code>.</p>

tread
<p>Your container image has a port opened during the build (looks like port 8080 in your case) using the <a href="https://docs.docker.com/engine/reference/builder/#expose" rel="noreferrer">EXPOSE command in the Dockerfile</a>. Since the exposed port is baked into the image, k8s does not keep track of this open port since k8s does not need to take steps to open it.</p>

<p>Since k8s is not responsible for opening the port, you won't be able to find the listening port using kubectl or checking the pod YAML</p>
