This tutorial shows how to expose service endpoints in multiple Namespaces using API Gateway Controller.

CAUTION: Exposing a workload to the outside world causes a potential security vulnerability, so tread carefully. In a production environment, secure the workload you expose with OAuth2 or JWT.

Prerequisites

1. Create three Namespaces: one for an instance of the HttpBin service, one for a sample Function, and one for an APIRule custom resource (CR). Deploy an instance of the HttpBin service and a sample Function in their respective Namespaces. To learn how to do it, follow the Create a workload tutorial.

   NOTE: Remember to enable the Istio sidecar proxy injection in each Namespace.

2. Export the Namespaces' names as environment variables:

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   export NAMESPACE_HTTPBIN={NAMESPACE_NAME}
   export NAMESPACE_FUNCTION={NAMESPACE_NAME}
   export NAMESPACE_APIRULE={NAMESPACE_NAME}

3. Depending on whether you use your custom domain or a Kyma domain, export the necessary values as environment variables:

   • Custom domain
   • Kyma domain

Expose and access your workloads in multiple Namespaces

1. Expose the HttpBin and Function services in their respective Namespaces by creating an APIRule CR in its own Namespace. Run:

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   cat <<EOF | kubectl apply -f -
   apiVersion: gateway.kyma-project.io/v1beta1
   kind: APIRule
   metadata:
     name: httpbin-and-function
     namespace: $NAMESPACE_APIRULE
   spec:
     host: httpbin-and-function.$DOMAIN_TO_EXPOSE_WORKLOADS
     gateway: $GATEWAY
     rules:
       - path: /headers
         methods: ["GET"]
         service:
           name: httpbin
           namespace: $NAMESPACE_HTTPBIN
           port: 8000
         accessStrategies:
           - handler: noop
         mutators:
           - handler: noop
       - path: /function
         methods: ["GET"]
         service:
           name: function
           namespace: $NAMESPACE_FUNCTION
           port: 80
         accessStrategies:
           - handler: noop
         mutators:
           - handler: noop
   EOF

   NOTE: If you are running Kyma on k3d, add httpbin.kyma.local to the entry with k3d IP in your system's /etc/hosts file.

2. Call the HttpBin endpoint by sending a GET request to the HttpBin service:

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   curl -ik -X GET https://httpbin-and-function.$DOMAIN_TO_EXPOSE_WORKLOADS/headers

   If successful, the call returns the code 200 OK response.

3. Call the Function endpoint by sending a GET request to the Function service:

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   curl -ik -X GET https://httpbin-and-function.$DOMAIN_TO_EXPOSE_WORKLOADS/function

   If successful, the call returns the code 200 OK response.