Gateways

Procedure

1. Create namespace called httpbin by running the following command:

   $ oc create namespace httpbin

2. Enable sidecar injection in the namespace. If you are using the InPlace upgrade strategy, run the following command:

   $ oc label namespace httpbin istio-injection=enabled

   Note

   If you are using the RevisionBased upgrade strategy, run the following commands:

   1. To find your <revision-name>, run the following command:

      $ oc get istiorevisions.sailoperator.io

      You will get an output similar to the following example:

      NAME      TYPE    READY   STATUS    IN USE   VERSION   AGE
      default   Local   True    Healthy   True    v1.24.3   3m33s

   2. Label the namespace with the revision name to enable sidecar injection:

      $ oc label namespace httpbin istio.io/rev=default

3. Deploy a sample service named httpbin by running the following command:

   $ oc apply -n httpbin -f https://raw.githubusercontent.com/openshift-service-mesh/istio/refs/heads/master/samples/httpbin/httpbin.yaml

4. Create a YAML file named httpbin-gw.yaml that defines an Istio Gateway resource. This resource configures gateway proxies to expose port 80 (HTTP) for the host, httpbin.example.com.

   You can see the following example configuration for reference:

   apiVersion: networking.istio.io/v1
   kind: Gateway
   metadata:
     name: httpbin-gateway
     namespace: httpbin
   spec:
     selector:
       istio: <gateway_name>
     servers:
     - port:
         number: 80
         name: http
         protocol: HTTP
       hosts:
       - httpbin.example.com

   • spec.selector specifies the unique label or set of labels in the pod template of the gateway proxy Deployment. By default, the Istio Gateway resource configuration will apply to matching gateway pods in all namespaces.
   • spec.servers.hosts specifies a list of addresses that the clients use when attempting to access a mesh service at the associated port.

5. Apply the YAML file by running the following command:

   $ oc apply -f httpbin-gw.yaml

6. Create a YAML file named httpbin-vs.yaml for a VirtualService. The VirtualService defines the rules that route traffic from the gateway proxy to the httpbin service.

   You can see the following example configuration for reference:

   apiVersion: networking.istio.io/v1
   kind: VirtualService
   metadata:
     name: httpbin
     namespace: httpbin
   spec:
     hosts:
     - httpbin.example.com
     gateways:
     - httpbin-gateway
     http:
     - match:
       - uri:
           prefix: /status
       - uri:
           prefix: /headers
       route:
       - destination:
           port:
             number: 8000
           host: httpbin

   • spec.hosts the destination hosts for the VirtualService routing rules. The Istio Gateway resource must expose the hosts that you bind to the VirtualService.
   • spec.gateways binds the VirtualService to the Istio Gateway resource created in the previous step by adding the Gateway name to the list of gateways.
   • spec.http.route route matching traffic to the httpbin service deployed earlier by defining a destination that includes the host and port of the httpbin Service.

7. Apply the YAML file by running the following command:

   $ oc apply -f httpbin-vs.yaml

8. For verification purposes, create a namespace for a curl client by running the following command:

   $ oc create namespace curl

9. Deploy the curl client by running the following command:

   $ oc apply -n curl -f https://raw.githubusercontent.com/openshift-service-mesh/istio/refs/heads/master/samples/curl/curl.yaml

10. Set a CURL_POD variable with the name of the curl pod by running the following command:

    $ CURL_POD=$(oc get pods -n curl -l app=curl -o jsonpath='{.items[*].metadata.name}')

11. Using the curl client, send a request to the /headers endpoint of the httpbin application through the ingress gateway Service resource. Set the Host header of the request to httpbin.example.com to match the host that the Istio Gateway and VirtualService resources specify. Run the following curl command to send the request:

    $ oc exec $CURL_POD -n curl -- \
      curl -s -I \
        -H Host:httpbin.example.com \
        <gateway_name>.<gateway_namespace>.svc.cluster.local/headers

12. The response should have a 200 OK HTTP status indicating that the request was successful.

    Example output

    HTTP/1.1 200 OK
    server: istio-envoy
    ...

13. Send a curl request to an endpoint that does not have a corresponding URI prefix match defined in the httpbin VirtualService by running the following command:

    $ oc exec $CURL_POD -n curl -- \
      curl -s -I \
        -H Host:httpbin.example.com \
        <gateway_name>.<gateway_namespace>.svc.cluster.local/get

    The response should return a 404 Not Found status as the httpbin VirtualService resource lacks a matching URI prefix for the /get endpoint.

    Example output

    HTTP/1.1 404 Not Found
    server: istio-envoy
    ...

14. Expose the gateway proxy to traffic outside the cluster by setting the Service type to LoadBalancer:

    $ oc patch service <gateway_name> -n <gateway_namespace> -p '{"spec": {"type": "LoadBalancer"}}'

    Note

    OpenShift Routes can also expose a gateway to traffic outside the cluster. For more information, see "Exposing a gateway to traffic outside the cluster using OpenShift Routes".

15. Verify that you can access the httpbin service from outside the cluster when using the external hostname or IP address of the gateway Service resource. Ensure that you set the INGRESS_HOST variable appropriately for the environment that your cluster is running in.

    1. If the cluster runs on AWS, set the INGRESS_HOST variable by running the following command:

       $ INGRESS_HOST=$(oc get service <gateway_name> -n <gateway_namespace> -o jsonpath='{.status.loadBalancer.ingress[0].hostname}')

    2. If the cluster runs on GCP or Azure, set the INGRESS_HOST variable by running the following command:

       $ INGRESS_HOST=$(oc get service <gateway_name> -n <gateway_namespace> -o jsonpath='{.status.loadBalancer.ingress[0].ip}')

    3. Send a curl request to the httpbin service using the host of the gateway by running the following command:

       $ curl -s -I -H Host:httpbin.example.com http://$INGRESS_HOST/headers

16. Verify that the response has the HTTP/1.1 200 OK status, which indicates that the request was successful.

Procedure

1. Create a namespace called httpbin by running the following command:

   $ oc create namespace httpbin

2. Deploy a sample service named httpbin by running the following command:

   $ oc apply -n httpbin -f https://raw.githubusercontent.com/openshift-service-mesh/istio/refs/heads/master/samples/httpbin/httpbin.yaml

3. Create a YAML file named httpbin-gw.yaml that defines a Kubernetes Gateway resource. This resource configures gateway proxies to expose port 80 (HTTP) for the host, httpbin.example.com.

   Example gateway resource file

   apiVersion: gateway.networking.k8s.io/v1
   kind: Gateway
   metadata:
     name: httpbin-gateway
     namespace: httpbin
   spec:
     gatewayClassName: istio
     listeners:
     - name: default
       hostname: "httpbin.example.com" 

   1

   
       port: 80
       protocol: HTTP
       allowedRoutes:
         namespaces:
           from: All

   1 1

   Specifies the virtual hostname that clients use when attempting to access a mesh service on the associated port.

4. Apply the YAML file by running the following command:

   $ oc apply -f httpbin-gw.yaml

5. Create a YAML file named httpbin-hr.yaml that defines an HTTPRoute resource. The HTTPRoute resource specifies the rules that route traffic from the gateway proxy to the httpbin service.

   Example HTTPRoute file

   apiVersion: gateway.networking.k8s.io/v1
   kind: HTTPRoute
   metadata:
     name: httpbin
     namespace: httpbin
   spec:
     parentRefs: 

   1

   
     - name: httpbin-gateway
       namespace: httpbin
     rules:
     - matches:
       - path:
           type: PathPrefix
           value: /status
       - path:
           type: PathPrefix
           value: /headers
       backendRefs: 

   2

   
       - name: httpbin
         port: 8000

   • spec.parentRefs binds the HTTPROUTE resource to the Kubernetes Gateway resource you created in the previous step.
   • spec.rules.backendRefs routes the matching traffic to the httpbin service by defining a backendRefs that includes the name and port of the httpbin service.

   The HTTPRoute resource specifies the rules that route traffic from the gateway proxy to the httpbin service.

6. Apply the YAML file by running the following command:

   $ oc apply -f httpbin-hr.yaml

7. Ensure that the Gateway API service is ready and has an allocated address by running the following command:

   $ oc wait --for=condition=programmed gtw httpbin-gateway -n httpbin

Verification

1. Create a namespace for a curl client by running the following command:

   $ oc create namespace curl

2. Deploy a curl client by running the following command:

   $ oc apply -n curl -f https://raw.githubusercontent.com/openshift-service-mesh/istio/refs/heads/master/samples/curl/curl.yaml

3. Set a CURL_POD variable with the name of the curl pod by running the following command:

   $ CURL_POD=$(oc get pods -n curl -l app=curl -o jsonpath='{.items[*].metadata.name}')

4. Using the curl client, send a request to the /headers endpoint of the httpbin application through the ingress gateway Service resource. Set the Host header of the request to httpbin.example.com to match the host that the Kubernetes Gateway and HTTPROUTE resources specify. Send the curl request by running the following command:

   $ oc exec $CURL_POD -n curl -- \
     curl -s -I \
       -H Host:httpbin.example.com \
       <gateway_name>-istio.<gateway_namespace>.svc.cluster.local/headers

   The response should return a 200 OK HTTP status, which indicates that the request was successful.

   Example output

   HTTP/1.1 200 OK
   server: istio-envoy
   ...

5. Send a curl request to an endpoint that does not have a corresponding Uniform Resource Identifier (URI) prefix match defined in the httpbin HTTPROUTE by running the following command:

   $ oc exec $CURL_POD -n curl -- \
     curl -s -I \
       -H Host:httpbin.example.com \
       <gateway_name>-istio.<gateway_namespace>.svc.cluster.local/get

   The response returns a 404 Not Found status. This is expected because the /get endpoint does not have a matching URI prefix in the httpbin HTTPROUTE resource.

   Example output

   HTTP/1.1 404 Not Found
   server: istio-envoy
   ...

6. Expose the gateway proxy to traffic outside the cluster by setting the Service type to LoadBalancer. Run the following command:

   $ oc patch service <gateway_name>-istio -n <gateway_namespace> -p '{"spec": {"type": "LoadBalancer"}}'

   Note

   OpenShift Routes can also expose a gateway to traffic outside the cluster. For more information, see "Exposing a gateway to traffic outside the cluster using OpenShift Routes".

7. Verify that you can access the httpbin service from outside the cluster when using the external hostname or IP address of the gateway Service resource. Ensure that you set the INGRESS_HOST variable appropriately for the environment in which your cluster is running.

   1. Set the INGRESS_HOST variable by running the following command:

      $ export INGRESS_HOST=$(oc get gtw <gateway_name> -n <gateway_namespace> -o jsonpath='{.status.addresses[0].value}')

   2. Set the INGRESS_PORT variable by running the following command:

      $ INGRESS_PORT=$(oc get gtw <gateway_name> -n <gateway_namespace> -o jsonpath='{.spec.listeners[?(@.name=="http")].port}')

   3. Using the gateway host, send a curl request to the httpbin service by running the following command:

      $ curl -s -I -H Host:httpbin.example.com http://$INGRESS_HOST:$INGRESS_PORT/headers

8. Verify that the response has the HTTP/1.1 200 OK status, which indicates that the request was successful.

Procedure

1. Create a namespace called curl by running the following command:

   $ oc create namespace curl

2. Depending on the update strategy you are using, enable sidecar injection in the namespace by running the appropriate commands:

   1. If you are using the InPlace update strategy, run the following command:

      $ oc label namespace curl istio-injection=enabled

   2. If you are using the RevisionBased update strategy, run the following commands:

      1. Display the revision name by running the following command:

         $ oc get istiorevisions.sailoperator.io

         You will get an output similar to the following example:

         NAME     TYPE    READY   STATUS    IN USE   VERSION   AGE
         default  Local   True    Healthy   True     v1.24.3   3m33s

      2. Label the namespace with the revision name to enable sidecar injection by running the following command:

         $ oc label namespace curl istio.io/rev=default

3. Deploy a curl application by running the following command:

   $ oc apply -n curl -f https://raw.githubusercontent.com/openshift-service-mesh/istio/refs/heads/master/samples/curl/curl.yaml

4. Export a CURL_POD environment variable and initialize it with the name of the curl pod by running the following command:

   $ export CURL_POD=$(oc get pod -n curl -l app=curl -o jsonpath='{.items[0].metadata.name}')

5. Create a YAML file named http-se.yaml that directs traffic from the mesh to an external service. The following example defines a ServiceEntry for a URL:

   Example configuration

   apiVersion: networking.istio.io/v1
   kind: ServiceEntry
   metadata:
     name: egress-se
     namespace: curl
   spec:
     hosts:
       - docs.redhat.com
     ports:
       - number: 80
         name: http-port
         protocol: HTTP
     location: MESH_EXTERNAL
     resolution: DNS

6. Apply the YAML file by running the following command:

   $ oc apply -f http-se.yaml

7. Ensure that you applied the ServiceEntry configuration correctly. Send an HTTP request to the host that you specified in the previous step by running the following command:

   $ oc exec "$CURL_POD" -n curl -c curl -- curl -sSL -o /dev/null -D - http://docs.redhat.com

   This command should return HTTP status codes, such as 301 (redirect) or 200 (success), indicating that the connection works.

8. Create a YAML file named http-gtw.yaml that creates an egress Gateway and routes traffic from the mesh to the host specified for the external service, similar to the following example:

   Example configuration

   apiVersion: networking.istio.io/v1alpha3
   kind: Gateway
   metadata:
     name: egress-gw
     namespace: <gateway_namespace> # Namespace where the egress gateway is deployed
   spec:
     selector:
       istio: <gateway_name> # Selects the egress-gateway instance to handle this traffic
     servers:
       - port:
           number: 80
           name: http
           protocol: HTTP
         hosts:
           - docs.redhat.com # External service host, not a full URL.
   ---
   apiVersion: networking.istio.io/v1alpha3
   kind: DestinationRule
   metadata:
     name: egress-dr
     namespace: <gateway_namespace> # Namespace where the egress gateway is deployed
   spec:
     host: <gateway_name>.<gateway_namespace>.svc.cluster.local
     subsets:
       - name: rh-docs

9. Apply the YAML file by running the following command:

   $ oc apply -f http-gtw.yaml

10. Create a YAML file named http-vs.yaml that sets up a VirtualService to manage the flow of traffic from the application sidecars through the egress gateway to the external host, similar to the following example:

    Example configuration

    apiVersion: networking.istio.io/v1alpha3
    kind: VirtualService
    metadata:
      name: egress-vs
      namespace: curl # Namespace where the curl pod is running
    spec:
      hosts:
        - docs.redhat.com # External service host, not a full URL.
      gateways:
        - mesh
        - <gateway_namespace>/egress-gw # Egress gateway name defined in the file that you used in the previous step.
      http:
        - match:
            - gateways:
                - mesh
              port: 80
          route:
            - destination:
                host: <gateway_name>.<gateway_namespace>.svc.cluster.local
                subset: rh-docs
                port:
                  number: 80
              weight: 100
        - match:
            - gateways:
                - <gateway_namespace>/egress-gw # Egress gateway name defined in the file that you used in the previous step.
              port: 80
          route:
            - destination:
                host: docs.redhat.com
                port:
                  number: 80
              weight: 100

11. Apply the YAML file by running the following command:

    $ oc apply -f http-vs.yaml

12. Resend the HTTP request to the URL:

    $ oc exec "$CURL_POD" -n curl -c curl -- curl -sSL -o /dev/null -D - http://docs.redhat.com

    The terminal should display information similar to the following output:

    Example output

    ...
    HTTP/1.1 301 Moved Permanently
    ...
    location: <example_url>
    ...
    
    HTTP/2 200
    Content-Type: text/html; charset=utf-8

13. Ensure that the gateway routed the request by running the following command:

    $ oc logs deployment/<gateway_name> -n <gateway_namespace> | tail -1

    Note

    You must enable access logging for this verification step to work. You can enable access logging to the standard output by setting the spec.values.meshConfig.accessLogFile field to /dev/stdout in the Istio resource.

    The terminal should display information similar to the following output:

    Example output

    [2024-11-07T14:35:52.428Z] "GET / HTTP/2" 301 - via_upstream - "-" 0 0 24 24 "10.128.2.30" "curl/8.11.0" "79551af2-341b-456d-b414-9220b487a03b" "docs.redhat.com" "23.55.176.201:80" outbound|80||docs.redhat.com 10.128.2.29:49766 10.128.2.29:80 10.128.2.30:38296 -

Procedure

1. Optional: Enable the {k8} Gateway API custom resource definitions (CRDs).

   Note

   As of Kubernetes 1.28 and OpenShift Container Platform 4.18 or earlier version of Red Hat OpenShift Service Mesh, the Kubernetes Gateway API CRDs are not available by default and you must enabled the CRDs before you can use them. OpenShift Container Platform 4.19 and later versions enable the CRDs by default.

   1. Create a YAML file named gateway-cr.yaml that enables the Kubernetes Gateway API CRDs, similar to the following example:

      Example Kubernetes Gateway Custom Resource (CR) file

      apiVersion: gateway.networking.k8s.io/v1
      kind: Gateway
      metadata:
        name: bookinfo-gateway
      spec:
        gatewayClassName: istio
        listeners:
        - name: http
          port: 80
          protocol: HTTP
          allowedRoutes:
            namespaces:
              from: Same
      ---
      apiVersion: gateway.networking.k8s.io/v1
      kind: HTTPRoute
      metadata:
        name: bookinfo
      spec:
        parentRefs:
        - name: bookinfo-gateway
        rules:
        - matches:
          - path:
              type: Exact
              value: /productpage
          - path:
              type: PathPrefix
              value: /static
          - path:
              type: Exact
              value: /login
          - path:
              type: Exact
              value: /logout
          - path:
              type: PathPrefix
              value: /api/v1/products
          backendRefs:
          - name: productpage
            port: 9080

   2. Apply the YAML file by running the following command:

      $ oc apply -f gateway-cr.yaml

2. Create a namespace called egress-gateway by running the following command:

   $ oc create namespace egress-gateway

3. Apply the istio-injection label to the namespace by running the following command:

   $ oc label namespace egress-gateway istio-injection=enabled

4. Create a YAML file named egress-gateway-cr.yaml that defines the egress gateway, similar to the following example:

   Example egress gateway CR file

   # ServiceEntry to allow traffic to httpbin.org
   apiVersion: networking.istio.io/v1
   kind: ServiceEntry
   metadata:
     name: httpbin-ext
   spec:
     hosts:
     - httpbin.org
     ports:
     - number: 80
       name: http
       protocol: HTTP
     location: MESH_EXTERNAL
     resolution: DNS
   ---
   # Gateway API Gateway for egress
   apiVersion: gateway.networking.k8s.io/v1
   kind: Gateway
   metadata:
     name: httpbin-egress-gateway
     annotations:
       networking.istio.io/service-type: ClusterIP
   spec:
     gatewayClassName: istio
     listeners:
     - name: http
       hostname: httpbin.org
       port: 80
       protocol: HTTP
       allowedRoutes:
         namespaces:
           from: Same
   ---
   # HTTPRoute to direct traffic from sidecars to the egress gateway
   apiVersion: gateway.networking.k8s.io/v1
   kind: HTTPRoute
   metadata:
     name: direct-httpbin-to-egress-gateway
   spec:
     parentRefs:
     - kind: ServiceEntry
       group: networking.istio.io
       name: httpbin-ext
     rules:
     - backendRefs:
       - name: httpbin-egress-gateway-istio
         port: 80
   ---
   # HTTPRoute to forward traffic from the egress gateway to httpbin.org
   apiVersion: gateway.networking.k8s.io/v1
   kind: HTTPRoute
   metadata:
     name: forward-httpbin-from-egress-gateway
   spec:
     parentRefs:
     - name: httpbin-egress-gateway
     hostnames:
     - httpbin.org
     rules:
     - backendRefs:
       - kind: Hostname
         group: networking.istio.io
         name: httpbin.org
         port: 80

   1. Apply the YAML file by running the following command:

      $ oc apply -f egress-gateway-cr.yaml

Verification

1. Verify the status of the gateway configuration by running the following command:

   $ oc describe gateway -n egress-gateway

   The Status column displays Programmed to indicate the required output.

2. Create a curl pod in the egress-gateway namespace by running the following command:

   $ oc run test-pod --image=curlimages/curl:latest -n egress-gateway --rm -it --restart=Never -- sh

3. By using the curl client, verify that you can access httpbin.org through the egress gateway by entering following command:

   $ curl -v http://httpbin.org/get

   The required output shows a response from httpbin.org that indicates egress traffic routes through the configured gateway.