Kubernetes NodePort not listening - nginx

Question

I'm doing some tutorials using k3d (k3s in docker) and my yml looks like this:
apiVersion: apps/v1
kind: Deployment
metadata:
name: nginx
labels:
app: nginx
spec:
selector:
matchLabels:
app: nginx
template:
metadata:
labels:
app: nginx
spec:
containers:
- name: nginx
image: nginx:alpine
ports:
- containerPort: 80
---
apiVersion: v1
kind: Service
metadata:
name: nginx
labels:
app: nginx
spec:
type: NodePort
selector:
app: nginx
ports:
- name: http
port: 80
targetPort: 80
With the resulting node port being 31747:
:~$ kubectl get service
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
kubernetes ClusterIP 10.43.0.1 <none> 443/TCP 18m
nginx NodePort 10.43.254.138 <none> 80:31747/TCP 17m
:~$ kubectl get endpoints
NAME ENDPOINTS AGE
kubernetes 172.18.0.2:6443 22m
nginx 10.42.0.8:80 21m
However wget does not work:
:~$ wget localhost:31747
Connecting to localhost:31747 ([::1]:31747)
wget: can't connect to remote host: Connection refused
:~$
What have I missed? I've ensured that my labels all say app: nginx and my containerPort, port and targetPort are all 80

Answer 1

The question is, is the NodePort range mapped from the host to the docker container acting as the node. The command docker ps will show you, for more details you can docker inspect $container_id and look at the Ports attribute under NetworkSettings. I don't have k3d around, but here is an example from kind.
$ docker ps
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
1d2225b83a73 kindest/node:v1.17.0 "/usr/local/bin/entr…" 18 hours ago Up 18 hours 127.0.0.1:32769->6443/tcp kind-control-plane
$ docker inspect kind-control-plane
[
{
# [...]
"NetworkSettings": {
# [...]
"Ports": {
"6443/tcp": [
{
"HostIp": "127.0.0.1",
"HostPort": "32769"
}
]
},
# [...]
}
]
If it is not, working with kubectl port-forward as suggested in the comment is probably the easiest approach. Alternatively, start looking into Ingress. Ingress is the preferred method to expose workloads outside of a cluster, and in the case of kind, they have support for Ingress. It seems k3d also has a way to map the ingress port to the host.

Answer 2

Turns out I didn't expose the ports when creating the cluster
https://k3d.io/usage/guides/exposing_services/

Answer 3

maybe, your pod is running on the other work node, not localhost. you should use the correct node ip.