NodePort Service not accepting connections : Error: connect ECONNREFUSED

Question

I've setup a simple Web API project and made an image. When I run the image directly using docker, I can't access the server using http://localhost:8080, but if I run docker inspect bridge I get back :

[
    {
        "Name": "bridge",
        "Id": "50a9ae0ed8721eaf1e4c5b1dd811d2be55d52e3cd7c012bfeb10d7e163c5d111",
        "Created": "2024-03-12T13:31:17.805598891-06:00",
        "Scope": "local",
        "Driver": "bridge",
        "EnableIPv6": false,
        "IPAM": {
            "Driver": "default",
            "Options": null,
            "Config": [
                {
                    "Subnet": "172.17.0.0/16",
                    "Gateway": "172.17.0.1"
                }
            ]
        },
        "Internal": false,
        "Attachable": false,
        "Ingress": false,
        "ConfigFrom": {
            "Network": ""
        },
        "ConfigOnly": false,
        "Containers": {
            "fc3d2b13168f662685e93fdc59c5508a147d6877147b97036d4c47b2f175ed7e": {
                "Name": "dreamy_mclaren",
                "EndpointID": "5173755a7c8158a30b195ec4d752f029eac0d84785ce20d2968ee18544374775",
                "MacAddress": "02:42:ac:11:00:02",
                "IPv4Address": "172.17.0.2/16",
                "IPv6Address": ""
            }
        },
        "Options": {
            "com.docker.network.bridge.default_bridge": "true",
            "com.docker.network.bridge.enable_icc": "true",
            "com.docker.network.bridge.enable_ip_masquerade": "true",
            "com.docker.network.bridge.host_binding_ipv4": "0.0.0.0",
            "com.docker.network.bridge.name": "docker0",
            "com.docker.network.driver.mtu": "1500"
        },
        "Labels": {}
    }
]

So then I try a GET request to http://172.17.0.2:8080/api/platforms and get back the expected response. I'm not sure where this subnet/gateway is coming from. By default I would expect to be able to use localhost. I went ahead and pushed the image to Dockerhub regardless. This issue is compounded when I try to setup a Deployment for this image, and a NodePort service:

platforms-depl.yaml:

apiVersion: apps/v1
kind: Deployment
metadata:
  name: platforms-depl
spec:
  replicas: 1
  selector:
    matchLabels:
      app: platformservice
  template:
    metadata:
      labels:
        app: platformservice
    spec:
      containers:
        - name: platformservice
          image: itunbridge/platformservice:latest
          ports:
            - containerPort: 80

platforms-np-srv.yaml:

apiVersion: v1
kind: Service
metadata:
  name: platformservice-srv
spec:
  type: NodePort
  selector:
    app: platformservice
  ports:
    - name: platformservice
      protocol: TCP
      port: 80
      targetPort: 80

Then I run: kubectl apply -f platforms-depl.yaml and kubectl apply -f platforms-np-srv.yaml

I can see which port was assigned with kubectl get services:

NAME                  TYPE        CLUSTER-IP       EXTERNAL-IP   PORT(S)        AGE
kubernetes            ClusterIP   10.96.0.1        <none>        443/TCP        46m
platformservice-srv   NodePort    10.104.221.184   <none>        80:30201/TCP   44m

I then try: minikube service platformservice-srv --url which gives me a response of http://192.168.59.100:30201

But none of these addresses give a response:

• http://192.168.59.100:30201/api/platforms
• http://10.104.221.184:30201/api/platforms
• http://localhost:30201/api/platforms
• http://172.17.0.2:30201/api/platforms
• http://10.104.221.184:30201/api/platforms
• http://10.244.0.5:30201/api/platforms

Answer 1

For some strange reason, the default ASPNETCORE_URLS Environment variable was set to http://+:8080 (as opposed to http://+80). After I updated my docker file:

COPY --from=build-env /app/out .
ENV ASPNETCORE_URLS=http://+:80
ENTRYPOINT [ "dotnet", "PlatformService.dll" ]

I pushed the new image to Docker Hub, then set the new image in my deployment: kubectl set image deployment/platforms-depl platformservice=itunbridge/platformservice and kubectl rollout status deployment/platforms-depl then the NodePort configuration I had originally:

(platforms-np-srv.yaml):

apiVersion: v1
kind: Service
metadata:
  name: platformservice-srv
spec:
  type: NodePort
  selector:
    app: platformservice
  ports:
    - name: platformservice
      protocol: TCP
      port: 80
      targetPort: 80
      nodePort: 30201

This works with value targetPort: 80 and I could access the endpoint by finding the IP assigned to minikube ip (http://192.168.59.100:30201/api/platforms)

A big thank you to @DavidMaze for pointing this out and getting me to realize my Web API app was listening on port 8080.