Remove headers

Remove headers from requests before they reach the upstream. Use this when a client sends headers that the backend service should not receive, such as internal routing hints, authentication tokens, or debugging headers added by a proxy.

Before you begin

1. Set up an agentgateway proxy.
2. Install the httpbin sample app.

Remove request headers

In this example, you remove the x-debug-trace request header before the request is forwarded to the upstream.

1. Send a request to the httpbin app and include the x-debug-trace request header. Verify that httpbin echoes it back in the response body.

   Cloud Provider LoadBalancerPort-forward for local testing

   curl -s http://$INGRESS_GW_ADDRESS:80/get \
    -H "host: www.example.com:80" \
    -H "x-debug-trace: true"

   curl -s localhost:8080/get \
   -H "host: www.example.com" \
   -H "x-debug-trace: true"

   Example output:

   {
     "args": {},
     "headers": {
       "Accept": [
         "*/*"
       ],
       "Host": [
         "www.example.com"
       ],
       "User-Agent": [
         "curl/8.7.1"
       ],
       "X-Debug-Trace": [
         "true"
       ]
     },
     "origin": "10.244.0.6:12345",
     "url": "http://www.example.com/get"
   }
   

   The x-debug-trace header is present in the echoed headers.

2. Create an AgentgatewayPolicy resource with your transformation rules.

   kubectl apply -f- <<EOF
   apiVersion: agentgateway.dev/v1alpha1
   kind: AgentgatewayPolicy
   metadata:
     name: transformation
     namespace: httpbin
   spec:
     targetRefs:
     - group: gateway.networking.k8s.io
       kind: HTTPRoute
       name: httpbin
     traffic:
       transformation:
         request:
           remove:
           - x-debug-trace
   EOF

3. Send another request with the x-debug-trace request header. Verify that you get back a 200 HTTP response code and that the x-debug-trace header is no longer present in the headers echoed back by httpbin.

   Cloud Provider LoadBalancerPort-forward for local testing

   curl -vi http://$INGRESS_GW_ADDRESS:80/get \
    -H "host: www.example.com:80" \
    -H "x-debug-trace: true"

   curl -vi localhost:8080/get \
   -H "host: www.example.com" \
   -H "x-debug-trace: true"

   Example output:

   < HTTP/1.1 200 OK
   HTTP/1.1 200 OK
   ...
   
   {
     "args": {},
     "headers": {
       "Accept": [
         "*/*"
       ],
       "Host": [
         "www.example.com"
       ],
       "User-Agent": [
         "curl/8.7.1"
       ]
     },
     "origin": "10.244.0.6:12345",
     "url": "http://www.example.com/get"
   }
   

   The x-debug-trace header is absent from the echoed headers, confirming it was stripped before the request reached the upstream.

Cleanup

kubectl delete AgentgatewayPolicy transformation -n httpbin