compression docs

Signed-off-by: Huabing Zhao <[email protected]>

site/content/en/latest/tasks/traffic/response-compression.md

@@ -0,0 +1,104 @@
+---
+title: "Response Compression"
+---
+
+Response Compression allows you to compress the response from the backend before sending it to the client. This can be useful for scenarios where the backend sends large responses that can be compressed to reduce the network bandwidth. However, this comes with a trade-off of increased CPU usage on the Envoy side to compress the response.
+
+## Installation
+
+Follow the steps from the [Quickstart](../../quickstart) to install Envoy Gateway and the example manifest.
+Before proceeding, you should be able to query the example backend using HTTP.
+
+## Testing Response Compression
+
+Envoy Gateway supports Brotli and Gzip compression algorithms. You can enable compression by specifying the compression types in the `BackendTrafficPolicy` resource. If you specify multiple compression types, Envoy will use the compression type that is requested by the client in the `Accept-Encoding` header.
+
+{{< tabpane text=true >}}
+{{% tab header="Apply from stdin" %}}
+
+```shell
+cat <<EOF | kubectl apply -f -
+apiVersion: gateway.envoyproxy.io/v1alpha1
+kind: BackendTrafficPolicy
+metadata:
+  name: response-compression
+spec:
+  targetRef:
+    group: gateway.networking.k8s.io
+    kind: HTTPRoute
+    name: backend
+  compression:
+    - type: Brotli
+    - type: Gzip
+EOF
+```
+
+{{% /tab %}}
+{{% tab header="Apply from file" %}}
+Save and apply the following resource to your cluster:
+
+```yaml
+---
+apiVersion: gateway.envoyproxy.io/v1alpha1
+kind: BackendTrafficPolicy
+metadata:
+  name: response-compression
+spec:
+  targetRef:
+    group: gateway.networking.k8s.io
+    kind: HTTPRoute
+    name: backend
+  compression:
+    - type: Brotli
+    - type: Gzip
+```
+
+{{% /tab %}}
+{{< /tabpane >}}
+
+
+Send requests to the Envoy Gateway with the `Accept-Encoding` header to specify the compression type. The quantity value in the `Accept-Encoding` header is used to specify the priority of the compression type. The compression type with the highest quantity that is configured in the `BackendTrafficPolicy` resource will be used.
+
+```shell
+curl --verbose --header "Host: www.example.com" --header "Accept-Encoding: br;q=1.0, gzip;q=0.8" http://$GATEWAY_HOST/
+```
+
+```console
+*   Trying 172.18.0.200:80...
+* Connected to 172.18.0.200 (172.18.0.200) port 80
+> GET / HTTP/1.1
+> Host: www.example.com
+> User-Agent: curl/8.5.0
+> Accept: */*
+> Accept-Encoding: br;q=1.0, gzip;q=0.8
+>
+< HTTP/1.1 200 OK
+< content-type: application/json
+< x-content-type-options: nosniff
+< date: Wed, 15 Jan 2025 08:23:42 GMT
+< vary: Accept-Encoding
+< content-encoding: br
+< transfer-encoding: chunked
+```
+
+```shell
+curl --verbose --header "Host: www.example.com" --header "Accept-Encoding: br;q=0.8, gzip;q=1.0" http://$GATEWAY_HOST/
+```
+
+```console
+*   Trying 172.18.0.200:80...
+* Connected to 172.18.0.200 (172.18.0.200) port 80
+> GET / HTTP/1.1
+> Host: www.example.com
+> User-Agent: curl/8.5.0
+> Accept: */*
+> Accept-Encoding: br;q=0.8, gzip;q=1.0
+>
+< HTTP/1.1 200 OK
+< content-type: application/json
+< x-content-type-options: nosniff
+< date: Wed, 15 Jan 2025 08:29:22 GMT
+< content-encoding: gzip
+< vary: Accept-Encoding
+< transfer-encoding: chunked
+```