gcp-fanout-ingress.sh

#! /bin/bash

# Get credentials for cluster <cluster> (which must exist in your working project)
# gcloud container clusters list
# gcloud container clusters get-credentials <cluster>

# Poke around ...
# kubectl get deployments
# kubectl get services
# kubectl get ingress

# Create the first deployment "web1" and service "web1-service". To keep this documentation simple I'm using heredocs. Note that the container exposes port 8080 and the service maps port 80 to the container's 8080.
cat << EOF | kubectl apply -f -
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
  name: web1
  namespace: default
spec:
  selector:
    matchLabels:
      app: web1
  template:
    metadata:
      labels:
        app: web1
    spec:
      containers:
      - image: gcr.io/google-samples/hello-app:1.0
        imagePullPolicy: IfNotPresent
        name: web1
        ports:
        - containerPort: 8080
          protocol: TCP

EOF

cat << EOF | kubectl apply -f -
apiVersion: v1
kind: Service
metadata:
  name: web1-service
spec:
  selector:
    app: web1
  type: NodePort
  ports:
  - protocol: TCP
    port: 80
    targetPort: 8080

EOF

# Create the second deployment "web2" and service "web2-service"
cat << EOF | kubectl apply -f -
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
  name: web2
  namespace: default
spec:
  selector:
    matchLabels:
      app: web2
  template:
    metadata:
      labels:
        app: web2
    spec:
      containers:
      - image: gcr.io/google-samples/hello-app:1.0
        imagePullPolicy: IfNotPresent
        name: web2
        ports:
        - containerPort: 8080
          protocol: TCP

EOF

cat << EOF | kubectl apply -f -
apiVersion: v1
kind: Service
metadata:
  name: web2-service
spec:
  selector:
    app: web2
  type: NodePort
  ports:
  - protocol: TCP
    port: 80
    targetPort: 8080

EOF


# Name of the GCP reserved IP address. Note that it must be "global". I created this from the GCP web console: https://console.cloud.google.com/networking/addresses/list
SIP=reserved-global-static-address-001

# Create an ingress resource
cat << EOF | kubectl apply -f -
apiVersion: extensions/v1beta1
kind: Ingress
metadata:
  name: web-fanout-ingress
  annotations:
    kubernetes.io/ingress.global-static-ip-name: "$SIP"
spec:
  rules:
  - http:
      paths:
      - path: /*
        backend:
          serviceName: web1-service
          servicePort: 80
      - path: /v2/*
        backend:
          serviceName: web2-service
          servicePort: 80

EOF

# Wait a few minutes. Note the difference between routes / and /v2/ :-)

# What if I only wanted a basic ingress to a single exposed service? In this case "web1-service"
# SIP=reserved-global-static-address-002

# cat << EOF | kubectl apply -f -
# apiVersion: extensions/v1beta1
# kind: Ingress
# metadata:
#   name: web1-ingress
#   annotations:
#     kubernetes.io/ingress.global-static-ip-name: "$SIP"
# spec:
#   backend:
#     serviceName: web1-service
#     servicePort: 80
#
# EOF

# What if I wanted an ingress to a service prepended by a specific url pattern with a failback? In this case "web1-service" is the failback and "web2-service" uses a prepended path
# SIP=reserved-global-static-address-003

# apiVersion: extensions/v1beta1
# kind: Ingress
# metadata:
#   name: web-fanout-ingress-with-default-backend
#   annotations:
#     kubernetes.io/ingress.global-static-ip-name: "$SIP"
# spec:
#   backend:
#     serviceName: web1-service
#     servicePort: 80
#   rules:
#   - http:
#       paths:
#       - path: /v2/*
#         backend:
#           serviceName: web2-service
#           servicePort: 80
#
# EOF