Kubernetes - Deploying older version of app in new API

Question

I'm working with yaml files built for an older version of the API

apiVersion: extensions/v1beta1

I tried changing to

apiVersion: apps/v1 

But couldn't figure out the correct "selector" formatting. So I changed back to v1beta1

Then I ran across this command:

kubectl convert -f . | kubectl -n robot-shop create -f -

All seemed to deploy correctly. But now when I try to reach my app, I get connection refused. After some investigation, I took a look at iptables and see this:

iptables -L | grep 30080
REJECT     tcp  --  0.0.0.0/0            0.0.0.0/0            
/* robot-shop/web:8080 has no endpoints */ ADDRTYPE match 
dst-type LOCAL tcp dpt:30080 reject-with icmp-port- 
unreachable

After some more research, this seems to have something to do with kube-proxy and "selector".

Question is, what's the right course of action?
1. Change the fw rule to ACCEPT
2. make the correct changes to yaml file (need help with that)
 a. If so, do I delete the deployment and then make correct changes, then redeploy?

Here's my deployment yaml file:

apiVersion: extensions/v1beta1
kind: Deployment
metadata:
  annotations:
    kompose.cmd: kompose -f ../docker-compose.yaml convert
    kompose.version: 1.10.0 (8bb0907)
  creationTimestamp: null
  labels:
    io.kompose.service: web
  name: web
spec:
  replicas: 1
  strategy: {}
  template:
    metadata:
      creationTimestamp: null
      labels:
        io.kompose.service: web
    spec:
      containers:
      - image: linuxacademycontent/rs-web:latest
        name: web
        ports:
        - containerPort: 8080
        resources:
          limits:
            cpu: 200m
            memory: 100Mi
          requests:
            cpu: 100m
            memory: 50Mi
      restartPolicy: Always
status: {}

And my service yaml file:

apiVersion: v1
kind: Service
metadata:
  annotations:
    kompose.cmd: kompose -f ../docker-compose.yaml convert
    kompose.version: 1.10.0 (8bb0907)
  creationTimestamp: null
  labels:
    io.kompose.service: web
  name: web
spec:
  type: NodePort
  ports:
  - name: "8080"
    port: 8080
    targetPort: 8080
    nodePort: 30080
  selector:
    io.kompose.service: web
status:
  loadBalancer: {}

Answer 1

Prior to apps/v1 the selector field was implicitly picked up from the pod template's labels. So in your case it would be:

spec:
  selector:
    matchLabels:
      io.kompose.service: web

Starting with apps/v1 an explicit selector field is required by the Kubernetes API.

I would suggest not to change the iptables on your own as it it the responsibility of your Kubernetes network plugin and is most likely done well.

As far as I am concerned you may simple update the Deployment manifest and no uninstall is required.