hostPort not working in cluster created via kubeadm

[mikedanese]

From @linfan on October 30, 2016 16:26

Is this a request for help? (If yes, you should use our troubleshooting guide and community support channels, see http://kubernetes.io/docs/troubleshooting/.): No

What keywords did you search in Kubernetes issues before filing this one? (If you have found any duplicates, you should instead reply there.): nodePort, kubeadm

---

Is this a BUG REPORT or FEATURE REQUEST? (choose one): BUG REPORT

Kubernetes version (use kubectl version):

$ kubectl version
Client Version: version.Info{Major:"1", Minor:"4", GitVersion:"v1.4.3", GitCommit:"4957b090e9a4f6a68b4a40375408fdc74a212260", GitTreeState:"clean", BuildDate:"2016-10-16T06:36:33Z", GoVersion:"go1.6.3", Compiler:"gc", Platform:"linux/amd64"}
Server Version: version.Info{Major:"1", Minor:"4", GitVersion:"v1.4.5", GitCommit:"5a0a696437ad35c133c0c8493f7e9d22b0f9b81b", GitTreeState:"clean", BuildDate:"2016-10-29T01:32:42Z", GoVersion:"go1.6.3", Compiler:"gc", Platform:"linux/amd64"}

Environment:

• Cloud provider or hardware configuration: AWS
• OS (e.g. from ca): Ubuntu 16.04.1 LTS
• Kernel (e.g. uname -a): 4.4.0-31-generic x86_64 GNU/Linux
• Install tools: kubeadm
• Others: single node cluster, with calico network plugin

What happened:

nodePort attribute in pod does not map container port to host.

What you expected to happen:

Yaml file like:

ports:
- containerPort: 80
   hostPort: 80

should expose the container port 80 to host port 80.

How to reproduce it (as minimally and precisely as possible):

Create a pod use below yaml file:

apiVersion: v1
kind: Pod
metadata:
  name: demo
spec:
  containers:
  - name: nginx-demo
    image: nginx
    ports:
    - containerPort: 80
      hostPort: 80

Then use curl <node-ip>:80 try access it, will get Connection refused error.

Check the docker container via docker inspect <container-id>, the container port is actually not exposed:

"HostConfig": {
  "PortBindings": null
}
"Config": {
  "ExposedPorts": {
    "443/tcp": {},
    "80/tcp": {}
  }
}
"NetworkSettings": {
  "Ports": null,
}

Anything else do we need to know:

Issue was found originally because the rc-default.yaml file in ingress example require nodePort.

Copied from original issue: kubernetes/kubernetes#35875

[mikedanese]

From @luxas on October 30, 2016 19:21

This is a known issue, but I agree we should document it.
See: kubernetes/kubernetes#31307

We're using cni networking.

Do you want to make the change in the docs or should I take it?

[mikedanese]

From @linfan on November 3, 2016 17:42

Sure, PR-1615 created.

[luxas]

This is documented both on the kubeadm page and on the network plugin page