Add request header tutorial to how-to guides (#2715)

Add request header tutorial to how-to guides

Problem: Users need a consolidated document for both request and response header modifiers

Solution: Updated existing response header modifier guide with request header modifier docs.

Author: salonichf5

examples/http-request-header-filter/README.md

@@ -1,78 +1,3 @@
-# Example
+# HTTP request headers example
 
-In this example we will deploy NGINX Gateway Fabric and configure traffic routing for a simple echo server.
-We will use HTTPRoute resources to route traffic to the echo server, using the `RequestHeaderModifier` filter to modify
-headers to the request.
-
-## Running the Example
-
-## 1. Deploy NGINX Gateway Fabric
-
-1. Follow the [installation instructions](https://docs.nginx.com/nginx-gateway-fabric/installation/) to deploy NGINX Gateway Fabric.
-
-1. Save the public IP address of NGINX Gateway Fabric into a shell variable:
-
-   ```text
-   GW_IP=XXX.YYY.ZZZ.III
-   ```
-
-1. Save the port of NGINX Gateway Fabric:
-
-   ```text
-   GW_PORT=<port number>
-   ```
-
-## 2. Deploy the Headers Application
-
-1. Create the headers Deployment and Service:
-
-   ```shell
-   kubectl apply -f headers.yaml
-   ```
-
-1. Check that the Pod is running in the `default` Namespace:
-
-   ```shell
-   kubectl -n default get pods
-   ```
-
-   ```text
-   NAME                      READY   STATUS    RESTARTS   AGE
-   headers-6f4b79b975-2sb28   1/1     Running   0          12s
-   ```
-
-## 3. Configure Routing
-
-1. Create the Gateway:
-
-   ```shell
-   kubectl apply -f gateway.yaml
-   ```
-
-1. Create the HTTPRoute resources:
-
-   ```shell
-   kubectl apply -f echo-route.yaml
-   ```
-
-## 4. Test the Application
-
-To access the application, we will use `curl` to send requests to the `headers` Service, including sending headers with
-our request.
-Notice our configured header values can be seen in the `requestHeaders` section below, and that the `User-Agent` header
-is absent.
-
-```shell
-curl -s --resolve echo.example.com:$GW_PORT:$GW_IP http://echo.example.com:$GW_PORT/headers -H "My-Cool-Header:my-client-value" -H "My-Overwrite-Header:dont-see-this"
-```
-
-```text
-Headers:
-  header 'Accept-Encoding' is 'compress'
-  header 'My-cool-header' is 'my-client-value, this-is-an-appended-value'
-  header 'My-Overwrite-Header' is 'this-is-the-only-value'
-  header 'Host' is 'echo.example.com:$GW_PORT'
-  header 'X-Forwarded-For' is '$GW_IP'
-  header 'Connection' is 'close'
-  header 'Accept' is '*/*'
-```
+This directory contains the YAML files used in the [Modify HTTP request and response headers](https://docs.nginx.com/nginx-gateway-fabric/how-to/traffic-management/request-response-headers/) guide.

examples/http-response-header-filter/README.md

@@ -1,3 +1,3 @@
-# HTTP Response Headers
+# HTTP response headers example
 
-This directory contains the YAML files used in the [HTTP Response Headers](https://docs.nginx.com/nginx-gateway-fabric/how-to/traffic-management/response-headers/) guide.
+This directory contains the YAML files used in the [Modify HTTP request and response headers](https://docs.nginx.com/nginx-gateway-fabric/how-to/traffic-management/request-response-headers/) guide.

site/content/how-to/data-plane-configuration.md

@@ -160,7 +160,7 @@ as arguments and add `/bin/sh` as the command. The deployment manifest should lo
 
 ## Configure PROXY protocol and RewriteClientIP settings
 
-When the request is passed through multiple proxies or load balancers, the client IP is set to the IP address of the server that last handled the request. To preserve the original client IP address, you can configure `RewriteClientIP` settings in the `NginxProxy` resource. `RewriteClientIP` has the fields: _mode_, _trustedAddresses_ and _setIPRecursively_.
+When a request is passed through multiple proxies or load balancers, the client IP is set to the IP address of the server that last handled the request. To preserve the original client IP address, you can configure `RewriteClientIP` settings in the `NginxProxy` resource. `RewriteClientIP` has the fields: _mode_, _trustedAddresses_ and _setIPRecursively_.
 
 **Mode** determines how the original client IP is passed through multiple proxies and the way the load balancer is set to receive it. It can have two values:
 
@@ -173,7 +173,7 @@ The choice of mode depends on how the load balancer fronting NGINX Gateway Fabri
 
 **SetIPRecursively** is a boolean field used to enable recursive search when selecting the client's address from a multi-value header. It is applicable in cases where we have a multi-value header containing client IPs to select from, i.e., when using `XForwardedFor` mode.
 
-The following command creates an `NginxProxy` resource with `RewriteClientIP` settings that set the mode to XForwardedFor, enables recursive search for finding the client IP and sets a CIDR, IPAddress and Hostname in the list of trusted addresses to find the original client IP address.
+The following command creates an `NginxProxy` resource with `RewriteClientIP` settings that set the mode to ProxyProtocol and sets a CIDR in the list of trusted addresses to find the original client IP address.
 
 ```yaml
 kubectl apply -f - <<EOF
@@ -184,18 +184,13 @@ metadata:
 spec:
   config:
     rewriteClientIP:
-      mode: XForwardedFor
-      setIPRecursively: true
+      mode: ProxyProtocol
       trustedAddresses:
       - type: CIDR
-        value: ":1/28"
-      - type: IPAddress
-        value: "192.68.74.28"
-      - type: Hostname
-        value: "cafe.com"
+        value "76.89.90.11/24"
 EOF
 ```
 
-For more information, see the `NginxProxy spec` in the [API reference]({{< relref "reference/api.md" >}}).
+For the full configuration API, see the `NginxProxy spec` in the [API reference]({{< relref "reference/api.md" >}}).
 
-{{< note >}} When sending curl requests to a server expecting proxy information, use the flag `--harproxy-protocol` to avoid broken header errors. {{< /note >}}
+{{< note >}} When sending curl requests to a server expecting proxy information, use the flag `--haproxy-protocol` to avoid broken header errors. {{< /note >}}