HTTP buffer filter

If the size of the request body is larger than the size you specify, the ingress gateway rejects the request with a 413 HTTP response.

Before you begin link

1. Set up Gloo Mesh Gateway in a single cluster.
2. Install Bookinfo and other sample apps.

3. Configure an HTTP listener on your gateway and set up basic routing for the sample apps.

4. Get the external address of your ingress gateway. The steps vary depending on the type of load balancer that backs the ingress gateway.

     export INGRESS_GW_ADDRESS=$(kubectl get svc -n gloo-mesh-gateways istio-ingressgateway -o jsonpath="{.status.loadBalancer.ingress[0]['hostname','ip']}")
   echo $INGRESS_GW_ADDRESS
     

   Note: Depending on your environment, you might see <pending> instead of an external IP address. For example, if you are testing locally in kind or minikube, or if you have insufficient permissions in your cloud platform, you can instead port-forward the service port of the ingress gateway:

     kubectl -n gloo-mesh-gateways port-forward deploy/istio-ingressgateway-1-23 8081
     

Configure HTTP buffer filter policies link

You can apply an HTTP buffer filter policy at the route level. For more information, see Applying policies.

Review the following sample configuration file.

  apiVersion: trafficcontrol.policy.gloo.solo.io/v2
kind: HTTPBufferPolicy
metadata:
  name: buffer-filter
  namespace: httpbin
spec:
  applyToRoutes:
  - route:
      labels:
        route: httpbin
  config:
    maxRequestBytes: 16384
  

Review the following table to understand this configuration. For more information, see the API docs.

Verify HTTP buffer filter policies link

1. Create a file with a size of 16385 bytes.

     for ((i=1;i<=16*1024+1;i++)); do echo -n "1" >> output.txt; done;
     

2. Send a POST request to the httpbin app and provide the file that you created as data input.

     curl -vik -X POST -H "X-httpbin: true" --data "@output.txt"  --resolve www.example.com:80:${INGRESS_GW_IP} http://www.example.com:80/post
     

     curl -vik -X POST -H "X-httpbin: true" --data "@output.txt"  --resolve www.example.com:443:${INGRESS_GW_IP} https://www.example.com:443/post
     

   
   Example output:

     ...
   * We are completely uploaded and fine
   * Connection state changed (MAX_CONCURRENT_STREAMS == 2147483647)!
   < HTTP/2 200 
   HTTP/2 200 
   < server: istio-envoy
   server: istio-envoy
   < date: Wed, 28 Dec 2022 19:23:15 GMT
   date: Wed, 28 Dec 2022 19:23:15 GMT
   < content-type: application/json
   content-type: application/json
   < content-length: 19192
   content-length: 19192
   ...
     

3. Apply the HTTP buffer filter policy to the httpbin app in your cluster. Note that this example sets the maximum request body size to 16 KB. Due to a bug in Envoy, this is the minimum size that must be set in order for the policy to work.

     kubectl apply -f- <<EOF
   apiVersion: trafficcontrol.policy.gloo.solo.io/v2
   kind: HTTPBufferPolicy
   metadata:
     name: buffer-filter
     namespace: httpbin
   spec:
     applyToRoutes:
     - route:
         labels:
           route: httpbin
     config:
       maxRequestBytes: 16384
   EOF
     

4. Send another POST request to the httpbin app and provide the data file that you created earlier. The request is now rejected with a 413 HTTP response code, because the size of the request body exceeds the maximumRequestBytes size that you specified in the HTTP buffer filter policy by 1 byte.

     curl -vik -X POST -H "X-httpbin: true" --data "@output.txt"  --resolve www.example.com:80:${INGRESS_GW_IP} http://www.example.com:80/post
     

     curl -vik -X POST -H "X-httpbin: true" --data "@output.txt"  --resolve www.example.com:443:${INGRESS_GW_IP} https://www.example.com:443/post
     

   Example output:

     ...
   * We are completely uploaded and fine
   * Connection state changed (MAX_CONCURRENT_STREAMS == 2147483647)!
   < HTTP/2 413 
   HTTP/2 413 
   < content-length: 17
   content-length: 17
   < content-type: text/plain
   content-type: text/plain
   ...
     

Cleanup link

  kubectl delete httpbufferpolicy buffer-filter -n httpbin
rm output.txt