旧バージョンのドキュメントを参照しています。最新のドキュメントはこちらをご参照ください。

Expose an external application

Learn to expose a service located outside the Kubernetes cluster using an Ingress.

Prerequisites: Install Kong Ingress Controller in your Kubernetes cluster and connect to Kong.

Prerequisites

Install Kong

You can install Kong in your Kubernetes cluster using Helm.

Add the Kong Helm charts:

 helm repo add kong https://charts.konghq.com
 helm repo update

Install Kong Ingress Controller and Kong Gateway with Helm:

 helm install kong kong/ingress -n kong --create-namespace 

Test connectivity to Kong

Kubernetes exposes the proxy through a Kubernetes service. Run the following commands to store the load balancer IP address in a variable named PROXY_IP:

Populate $PROXY_IP for future commands:

 export PROXY_IP=$(kubectl get svc --namespace kong kong-gateway-proxy -o jsonpath='{.status.loadBalancer.ingress[0].ip}')
 echo $PROXY_IP

Ensure that you can call the proxy IP:

 curl -i $PROXY_IP

The results should look like this:

 HTTP/1.1 404 Not Found
 Content-Type: application/json; charset=utf-8
 Connection: keep-alive
 Content-Length: 48
 X-Kong-Response-Latency: 0
 Server: kong/3.0.0
  
 {"message":"no Route matched with those values"}

Create a Kubernetes Service

Deploy a Kubernetes Service type=ExternalName using the hostname of the application you want to expose.

 echo "
 kind: Service
 apiVersion: v1
 metadata:
   name: proxy-to-httpbin
 spec:
   ports:
   - protocol: TCP
     port: 80
   type: ExternalName
   externalName: httpbin.konghq.com
 " | kubectl apply -f -

The results should look like this:

 service/proxy-to-httpbin created

Create an Ingress to expose the service at the path /httpbin

Gateway API

Ingress

echo "
apiVersion: gateway.networking.k8s.io/v1beta1
kind: HTTPRoute
metadata:
  name: proxy-from-k8s-to-httpbin
  annotations:
    konghq.com/strip-path: 'true'
spec:
  parentRefs:
  - name: kong
  hostnames:
  - 'kong.example'
  rules:
  - matches:
    - path:
        type: PathPrefix
        value: /httpbin
    backendRefs:
    - name: proxy-to-httpbin
      kind: Service
      port: 80
" | kubectl apply -f -

echo "
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: proxy-from-k8s-to-httpbin
  annotations:
    konghq.com/strip-path: 'true'
spec:
  ingressClassName: kong
  rules:
  - host: kong.example
    http:
      paths:
      - path: /httpbin
        pathType: ImplementationSpecific
        backend:
          service:
            name: proxy-to-httpbin
            port:
              number: 80
" | kubectl apply -f -

The results should look like this:

      Gateway API
    
      Ingress
    
httproute.gateway.networking.k8s.io/proxy-from-k8s-to-httpbin created
ingress.networking.k8s.io/proxy-from-k8s-to-httpbin created

Test the Service

curl -i -H 'Host:kong.example' $PROXY_IP/httpbin/anything

The results should look like this:

HTTP/1.1 200 OK
Date: Thu, 15 Dec 2022 21:31:47 GMT
Content-Type: application/json
Content-Length: 341
Connection: keep-alive
Server: gunicorn/19.9.0
Access-Control-Allow-Origin: *
Access-Control-Allow-Credentials: true
X-Kong-Upstream-Latency: 2
X-Kong-Proxy-Latency: 1
Via: kong/3.1.1

{
  "args": {},
  "data": "",
  "files": {},
  "form": {},
  "headers": {
    "Accept": "*/*",
    "Host": "httpbin.konghq.com",
    "User-Agent": "curl/7.86.0",
    "X-Amzn-Trace-Id": "Root=1-639b9243-7cdb670008b8189a5948d619"
  },
  "json": null,
  "method": "GET",
  "origin": "136.25.153.9",
  "url": "https://httpbin.konghq.com/anything"
}