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Route within one cluster

Use the ingress gateway to route incoming requests directly to a Kubernetes service within the same cluster.

For more information, see the following resources:

Before you begin

Configure a basic route table for direct routing to a Kubernetes service

  1. In the cluster where you deployed an instance of your app, create a virtual gateway. This virtual gateway selects the default Istio ingress gateway, which routes incoming traffic (north-south) to your service mesh.

    kubectl apply --context $REMOTE_CONTEXT1 -f- <<EOF
apiVersion: networking.gloo.solo.io/v2
kind: VirtualGateway
metadata:
  name: ingress-gateway
  namespace: gloo-mesh
spec:
  workloads:
    # Selects the istio ingress gateway in workload cluster 1
    - selector:
        labels:
          istio: ingressgateway
        cluster: ${REMOTE_CLUSTER1}
  listeners:
    # The port the ingress gateway listens on for incoming requests to route
    - port:
        number: 80
      http: {}
EOF

  2. Save the external address of the Istio ingress gateway. 

    
   export CLUSTER_1_INGRESS_ADDRESS=$(kubectl --context $REMOTE_CONTEXT1 get svc -n istio-system istio-ingressgateway -o jsonpath='{.status.loadBalancer.ingress[0].ip}')
   echo $CLUSTER_1_INGRESS_ADDRESS
   
    
   export CLUSTER_1_INGRESS_ADDRESS=$(kubectl --context $REMOTE_CONTEXT1 get svc -n istio-system istio-ingressgateway -o jsonpath='{.status.loadBalancer.ingress[0].hostname}')
   echo $CLUSTER_1_INGRESS_ADDRESS

  3. Ensure that the app is exposed by a Kubernetes service. In this example, the label app: single-app is used as the service selector. The service listens on port 3456 and forwards requests to port 9080.

    apiVersion: v1
kind: Service
metadata:
  labels:
    app: single-app
  name: single-app
  namespace: global
spec:
  ports:
  - name: http
    port: 3456
    protocol: TCP
    targetPort: 9080
  type: ClusterIP

  4. Create a basic route table to route requests to your app's service. This resource allows you to define how requests to endpoints should be routed, and is translated to the Istio VirtualService resource. In this example route table, all requests to the /single-app path are routed to the single-app service.

    kubectl apply --context $REMOTE_CONTEXT1 -n global -f- <<EOF
apiVersion: networking.gloo.solo.io/v2
kind: RouteTable
metadata:
  name: single-app-routes
  namespace: global
spec:
  # Applies to any host; can indicate a specific domain
  hosts:
    - '*'
  # Selects the virtual gateway you previously created
  virtualGateways:
    - name: ingress-gateway
      namespace: gloo-mesh
      cluster: ${REMOTE_CLUSTER1}
  http:
    # Route for the single-app service
    - name: single-app
      # Prefix matching
      matchers:
      - uri:
          prefix: /single-app
      # Forwarding directive
      forwardTo:
        destinations:
          # Reference to Kubernetes service in this cluster
          - ref:
              name: single-app
              namespace: global
              cluster: ${REMOTE_CLUSTER1}
            port:
              number: 9080
            kind: SERVICE
EOF

  5. Test the route to your app by curling the ingress gateway address and app path. For example, the following command appends /single-app for the sample app.

    curl http://$CLUSTER_1_INGRESS_ADDRESS/single-app

Example route table setup for BookInfo

If you do not have apps in an Istio service mesh to test with routing, you can complete the demo setup to install Gloo Mesh, Istio, and Bookinfo in your cluster. Then, follow Step 3: Expose the ingress gateway in the Multicluster federation and isolation with Bookinfo guide. These steps walk you through creating a virtual gateway and configuring a route table for the BookInfo services in cluster-1, which you can then test access to in your browser.

Next steps