For more information, see the Header manipulation API.

Before you begin

  1. Follow the Get started guide to install Gloo Gateway, set up a gateway resource, and deploy the httpbin sample app.

  2. Get the external address of the gateway and save it in an environment variable.

      export INGRESS_GW_ADDRESS=$(kubectl get svc -n gloo-system gloo-proxy-http -o jsonpath="{.status.loadBalancer.ingress[0]['hostname','ip']}")
echo $INGRESS_GW_ADDRESS  
  
      kubectl port-forward deployment/gloo-proxy-http -n gloo-system 8080:8080

Add response headers

Add response headers to responses before they are sent back to the client.

Use a VirtualHostOption resource to add response headers for responses from all routes that the gateway serves.

  1. Create a VirtualHostOption custom resource to specify your header manipulation rules. In the following example, the my-header: gloo-gateway header is added to each response.

      kubectl apply -n gloo-system -f- <<EOF
apiVersion: gateway.solo.io/v1
kind: VirtualHostOption
metadata:
  name: header-manipulation
  namespace: gloo-system
spec:
  options:
    headerManipulation:
      responseHeadersToAdd: 
        - header:
            key: "my-header"
            value: "gloo-gateway"
  targetRefs:
    group: gateway.networking.k8s.io
    kind: Gateway
    name: http
    namespace: gloo-system
EOF

  2. Send a request to the httpbin app and verify that the my-header header is added to the response.

    • LoadBalancer IP address or hostname
        curl -vik http://$INGRESS_GW_ADDRESS:8080/response-headers -H "host: www.example.com:8080"
    • Port-forward for local testing
        curl -vik localhost:8080/response-headers -H "host: www.example.com"

    Example output:

       * Mark bundle as not supporting multiuse
< HTTP/1.1 200 OK
HTTP/1.1 200 OK
< access-control-allow-credentials: true
access-control-allow-credentials: true
< access-control-allow-origin: *
access-control-allow-origin: *
< content-type: application/json; encoding=utf-8
content-type: application/json; encoding=utf-8
< date: Fri, 19 Apr 2024 13:26:23 GMT
date: Fri, 19 Apr 2024 13:26:23 GMT
< content-length: 3
content-length: 3
< x-envoy-upstream-service-time: 0
x-envoy-upstream-service-time: 0
< my-header: gloo-gateway
my-header: gloo-gateway
< server: envoy
server: envoy

  3. Optional: Clean up the resources that you created.

      kubectl delete virtualhostoption header-manipulation -n gloo-system

Use a RouteOption resource to add response headers to responses from a specific route.

  1. Create a RouteOption custom resource to specify your header manipulation rules. In the following example, the my-response: gloo-gateway header is added to each response.

      kubectl apply -n httpbin -f- <<EOF
apiVersion: gateway.solo.io/v1
kind: RouteOption
metadata:
  name: header-manipulation
  namespace: httpbin
spec:
  options:
    headerManipulation:
      responseHeadersToAdd:
        - header:
            key: "my-response"
            value: "gloo-gateway"
EOF

  2. Create an HTTPRoute resource for the httpbin app that references the RouteOptions that you just created.

      kubectl apply -f- <<EOF
apiVersion: gateway.networking.k8s.io/v1
kind: HTTPRoute
metadata:
  name: httpbin-headers
  namespace: httpbin
spec:
  parentRefs:
  - name: http
    namespace: gloo-system
  hostnames:
    - headers.example
  rules:
    - filters:
        - type: ExtensionRef
          extensionRef:
            group: gateway.solo.io
            kind: RouteOption
            name: header-manipulation
      backendRefs:
        - name: httpbin
          port: 8000
EOF

  3. Send a request to the httpbin app on the headers.example domain. Verify that you get back a 200 HTTP response code and that you see the my-response header in the response.

    • LoadBalancer IP address or hostname
        curl -vik http://$INGRESS_GW_ADDRESS:8080/response-headers -H "host: headers.example:8080"
    • Port-forward for local testing
        curl -vik localhost:8080/response-headers -H "host: headers.example"

    Example output:

       * Mark bundle as not supporting multiuse
< HTTP/1.1 200 OK
HTTP/1.1 200 OK
< access-control-allow-credentials: true
access-control-allow-credentials: true
< access-control-allow-origin: *
access-control-allow-origin: *
< content-type: application/json; encoding=utf-8
content-type: application/json; encoding=utf-8
< date: Fri, 19 Apr 2024 02:23:58 GMT
date: Fri, 19 Apr 2024 02:23:58 GMT
< content-length: 3
content-length: 3
< x-envoy-upstream-service-time: 0
x-envoy-upstream-service-time: 0
< my-response: gloo-gateway
my-response: gloo-gateway
< server: envoy
server: envoy

  4. Optional: Remove the resources that you created.

      kubectl delete httproute httpbin-headers -n httpbin
kubectl delete routeoption header-manipulation -n httpbin

Remove response headers

You can remove HTTP headers from a response before the response is sent back to the client.

Remove specific headers from all responses from the routes that the gateway serves.

  1. Send a request to the httpbin app and find the content-length header.

    • LoadBalancer IP address or hostname
        curl -vik http://$INGRESS_GW_ADDRESS:8080/response-headers -H "host: www.example.com:8080"
    • Port-forward for local testing
        curl -vik localhost:8080/response-headers -H "host: www.example.com"

    Example output:

       ...
* Mark bundle as not supporting multiuse
< HTTP/1.1 200 OK
HTTP/1.1 200 OK
< access-control-allow-credentials: true
access-control-allow-credentials: true
< access-control-allow-origin: *
access-control-allow-origin: *
< content-type: application/json; encoding=utf-8
content-type: application/json; encoding=utf-8
< date: Fri, 19 Apr 2024 13:37:36 GMT
date: Fri, 19 Apr 2024 13:37:36 GMT
< content-length: 3
content-length: 3
< x-envoy-upstream-service-time: 0
x-envoy-upstream-service-time: 0
< server: envoy
server: envoy

  2. Create a VirtualHostOption custom resource to specify your header manipulation rules. In the following example, the content-length header is removed from each response.

      kubectl apply -n gloo-system -f- <<EOF
apiVersion: gateway.solo.io/v1
kind: VirtualHostOption
metadata:
  name: header-manipulation
  namespace: gloo-system
spec:
  options:
    headerManipulation:
      responseHeadersToRemove: ["content-length"] 
  targetRefs:
    group: gateway.networking.k8s.io
    kind: Gateway
    name: http
    namespace: gloo-system
EOF

  3. Send a request to the httpbin app and verify that the content-length header is removed from the response.

    • LoadBalancer IP address or hostname
        curl -vik http://$INGRESS_GW_ADDRESS:8080/response-headers -H "host: www.example.com:8080"
    • Port-forward for local testing
        curl -vik localhost:8080/response-headers -H "host: www.example.com"

    Example output:

      * Mark bundle as not supporting multiuse
< HTTP/1.1 200 OK
HTTP/1.1 200 OK
< access-control-allow-credentials: true
access-control-allow-credentials: true
< access-control-allow-origin: *
access-control-allow-origin: *
< content-type: application/json; encoding=utf-8
content-type: application/json; encoding=utf-8
< date: Fri, 19 Apr 2024 13:51:53 GMT
date: Fri, 19 Apr 2024 13:51:53 GMT
< x-envoy-upstream-service-time: 0
x-envoy-upstream-service-time: 0
< server: envoy
server: envoy
< transfer-encoding: chunked
transfer-encoding: chunked

  4. Optional: Clean up the resources that you created.

      kubectl delete virtualhostoption header-manipulation -n gloo-system

You can remove HTTP headers from a response of a specific route before the response is sent back to the client.

  1. Send a request to the httpbin app and find the content-length header.

    • LoadBalancer IP address or hostname
        curl -vik http://$INGRESS_GW_ADDRESS:8080/response-headers -H "host: www.example.com:8080"
    • Port-forward for local testing
        curl -vik localhost:8080/response-headers -H "host: www.example.com"

    Example output:

       ...
* Mark bundle as not supporting multiuse
< HTTP/1.1 200 OK
HTTP/1.1 200 OK
< access-control-allow-credentials: true
access-control-allow-credentials: true
< access-control-allow-origin: *
access-control-allow-origin: *
< content-type: application/json; encoding=utf-8
content-type: application/json; encoding=utf-8
< date: Fri, 19 Apr 2024 16:40:01 GMT
date: Fri, 19 Apr 2024 16:40:01 GMT
< content-length: 3
content-length: 3
< x-envoy-upstream-service-time: 0
x-envoy-upstream-service-time: 0
< server: envoy
server: envoy

  2. Create a RouteOption resource to specify your header manipulation rules. In this example, you remove the content-length response header from each response.

      kubectl apply -n httpbin -f- <<EOF
apiVersion: gateway.solo.io/v1
kind: RouteOption
metadata:
  name: header-manipulation
  namespace: httpbin
spec:
  options:
    headerManipulation:
      responseHeadersToRemove: ["content-length"]
EOF

  3. Create an HTTPRoute resource for the httpbin app that references the RouteOptions that you just created.

      kubectl apply -f- <<EOF
apiVersion: gateway.networking.k8s.io/v1
kind: HTTPRoute
metadata:
  name: httpbin-headers
  namespace: httpbin
spec:
  parentRefs:
  - name: http
    namespace: gloo-system
  hostnames:
    - headers.example
  rules:
    - filters:
        - type: ExtensionRef
          extensionRef:
            group: gateway.solo.io
            kind: RouteOption
            name: header-manipulation
      backendRefs:
        - name: httpbin
          port: 8000
EOF

  4. Send a request to the httpbin app on the headers.example domain . Verify that the content-length response header is removed.

    • LoadBalancer IP address or hostname
        curl -vik http://$INGRESS_GW_ADDRESS:8080/response-headers -H "host: headers.example:8080"
    • Port-forward for local testing
        curl -vik localhost:8080/reesponse-headers -H "host: headers.example"

    Example output:

      * Mark bundle as not supporting multiuse
< HTTP/1.1 200 OK
HTTP/1.1 200 OK
< access-control-allow-credentials: true
access-control-allow-credentials: true
< access-control-allow-origin: *
access-control-allow-origin: *
< content-type: application/json; encoding=utf-8
content-type: application/json; encoding=utf-8
< date: Fri, 19 Apr 2024 13:51:53 GMT
date: Fri, 19 Apr 2024 13:51:53 GMT
< x-envoy-upstream-service-time: 0
x-envoy-upstream-service-time: 0
< server: envoy
server: envoy
< transfer-encoding: chunked
transfer-encoding: chunked

  5. Optional: Remove the resources that you created.

      kubectl delete httproute httpbin-headers -n httpbin
kubectl delete routeoption header-manipulation -n httpbin