Nginx ingress controller not working with namespace

[skoulouzis]

Describe the bug
Following the tutorial at https://www.youtube.com/watch?v=2VUQ4WjLxDg everything works as expected. However, if we add namespace to the deployments we get '503 Service Temporarily Unavailable' on all paths: '/', '/green', '/blue'

How To Reproduce
create new namespace:

kubectl create namespace example

install nginx-ingress:

helm install my-conf-nginx --namespace example  stable/nginx-ingress

create resources:

kubectl create -f ingress-resource-3.yaml -f nginx-deploy-blue.yaml -f nginx-deploy-green.yaml -f nginx-deploy-main.yaml

Resources:
ingress-resource-3.yaml

apiVersion: networking.k8s.io/v1beta1
kind: Ingress
metadata:
  namespace: example
  annotations:
    kubernetes.io/ingress.class: nginx
    nginx.ingress.kubernetes.io/rewrite-target: /
  name: ingress-resource-3
spec:
  rules:
  - host: fry.lab.uvalight.net
    http:
      paths:
      - path: /
        backend:
          serviceName: nginx-deploy-main
          servicePort: 80  
      - path: /blue
        backend:
          serviceName: nginx-deploy-blue
          servicePort: 80
      - path: /green
        backend:
          serviceName: nginx-deploy-green
          servicePort: 80

nginx-deploy-blue.yaml

apiVersion: apps/v1
kind: Deployment
metadata:
  namespace: example
  labels:
    run: nginx
  name: nginx-deploy-blue
spec:
  replicas: 1
  selector:
    matchLabels:
      run: nginx-blue
  template:
    metadata:
      labels:
        run: nginx-blue
    spec:
      volumes:
      - name: webdata
        emptyDir: {}
      initContainers:
      - name: web-content
        image: busybox
        volumeMounts:
        - name: webdata
          mountPath: "/webdata"
        command: ["/bin/sh", "-c", 'echo "<h1>I am <font color=blue>BLUE</font></h1>" > /webdata/index.html']
      containers:
      - image: nginx
        name: nginx
        volumeMounts:
        - name: webdata
          mountPath: "/usr/share/nginx/html"

nginx-deploy-green.yaml

apiVersion: apps/v1
kind: Deployment
metadata:
  namespace: example
  labels:
    run: nginx
  name: nginx-deploy-green
spec:
  replicas: 1
  selector:
    matchLabels:
      run: nginx-green
  template:
    metadata:
      labels:
        run: nginx-green
    spec:
      volumes:
      - name: webdata
        emptyDir: {}
      initContainers:
      - name: web-content
        image: busybox
        volumeMounts:
        - name: webdata
          mountPath: "/webdata"
        command: ["/bin/sh", "-c", 'echo "<h1>I am <font color=green>GREEN</font></h1>" > /webdata/index.html']
      containers:
      - image: nginx
        name: nginx
        volumeMounts:
        - name: webdata
          mountPath: "/usr/share/nginx/html"

nginx-deploy-main.yaml

apiVersion: apps/v1
kind: Deployment
metadata:
  namespace: example
  labels:
    run: nginx
  name: nginx-deploy-main
spec:
  replicas: 1
  selector:
    matchLabels:
      run: nginx-main
  template:
    metadata:
      labels:
        run: nginx-main
    spec:
      containers:
      - image: nginx
        name: nginx

Expose ports:

kubectl expose deploy nginx-deploy-blue --port 80 -n example
kubectl expose deploy nginx-deploy-green --port 80 -n example
kubectl expose deploy nginx-deploy-main --port 80 -n example

Expected behavior
For each path on the browser to show the corresponding nginx index.html

Screenshots (if any)

Environment (please complete the following information):

kubectl version --short
Client Version: v1.18.2
Server Version: v1.18.2

helm version --short
v3.2.0+ge11b7ce

Additional context
Add any other context about the problem here.

[justmeandopensource]

I will test it this weekend. Thanks