istio self cert, prefix routing, gateway in another namespace and virtual service routing to a k8s service

certs.yaml

apiVersion: cert-manager.io/v1alpha2
kind: ClusterIssuer
metadata:
  name: selfsigning-issuer
spec:
  selfSigned: {}

---

apiVersion: cert-manager.io/v1alpha2
kind: Certificate
metadata:
  name: awesome-io
  namespace: istio-system
spec:
  secretName: awesome-io
  # The use of the common name field has been deprecated since 2000
  commonName: "awesome.io"
  organization:
  - Awesome inc
  dnsNames:
  - awesome.io
  
  keySize: 2048
  keyAlgorithm: rsa
  keyEncoding: pkcs1
  
  issuerRef:
    name: selfsigning-issuer
    kind: ClusterIssuer
  
  privateKey:
    rotationPolicy: Always

gateway.yaml

apiVersion: networking.istio.io/v1alpha3
kind: Gateway
metadata:
  name: awesome-io-gateway
  namespace: istio-system
spec:
  selector:
    istio: ingressgateway # use istio default ingress gateway
  servers:
  - port:
      number: 443
      name: https
      protocol: HTTPS
    tls:
      mode: SIMPLE
      credentialName: awesome-io # must be the same as secret
    hosts:
    - "awesome.io"

  - port:
      number: 80
      name: http
      protocol: HTTP
    hosts:
    - "awesome.io"

service.yaml

apiVersion: v1
kind: Namespace
metadata:
  name: weather
  labels:
    istio-injection: enabled

---

apiVersion: v1
kind: ServiceAccount
metadata:
  namespace: weather
  name: weather

---

apiVersion: apps/v1
kind: Deployment
metadata:
  namespace: weather
  name: weather
spec:
  replicas: 1
  selector:
    matchLabels:
      app: weather
      version: v1
  template:
    metadata:
      labels:
        app: weather
        version: v1
    spec:
      serviceAccountName: weather
      containers:
      - image: docker.io/dbones/weather
        imagePullPolicy: IfNotPresent
        name: weather
        ports:
        - containerPort: 80

---
apiVersion: v1
kind: Service
metadata:
  namespace: weather
  name: weather
  labels:
    app: weather
spec:
  ports:
  - name: http
    port: 80
    targetPort: 80
  selector:
    app: weather
---

apiVersion: networking.istio.io/v1alpha3
kind: VirtualService
metadata:
  namespace: weather
  name: weather
spec:
  hosts:
  - "*"
  gateways:
  - istio-system/awesome-io-gateway
  http:
  - match:
    - uri:
        prefix: "/weather/"
    - uri:
        prefix: "/weather"
    rewrite:
      uri: "/"
    route:
    - destination:
        port:
          number: 80
        host: weather