dynamic proxy: add support for header based routing (#8869)

Signed-off-by: Raul Gutierrez Segales <rgs@pinterest.com>

Mirrored from https://github.com/envoyproxy/envoy @ 274f17cabe7f49f105c82919937ab710b9428261

envoy/api/v2/route/route.proto

@@ -727,6 +727,8 @@ message RouteAction {
   oneof host_rewrite_specifier {
     // Indicates that during forwarding, the host header will be swapped with
     // this value.
+    //
+    // [#next-major-version: host_rewrite_literal]
     string host_rewrite = 6;
 
     // Indicates that during forwarding, the host header will be swapped with
@@ -744,6 +746,8 @@ message RouteAction {
     //
     //   Pay attention to the potential security implications of using this option. Provided header
     //   must come from trusted source.
+    //
+    // [#next-major-version: host_rewrite_header]
     string auto_host_rewrite_header = 29;
   }
 

envoy/api/v3alpha/route/route.proto

@@ -667,6 +667,8 @@ message RouteAction {
   oneof host_rewrite_specifier {
     // Indicates that during forwarding, the host header will be swapped with
     // this value.
+    //
+    // [#next-major-version: host_rewrite_literal]
     string host_rewrite = 6;
 
     // Indicates that during forwarding, the host header will be swapped with
@@ -684,6 +686,8 @@ message RouteAction {
     //
     //   Pay attention to the potential security implications of using this option. Provided header
     //   must come from trusted source.
+    //
+    // [#next-major-version: host_rewrite_header]
     string auto_host_rewrite_header = 29;
   }
 

envoy/config/filter/http/dynamic_forward_proxy/v2alpha/dynamic_forward_proxy.proto

@@ -24,8 +24,31 @@ message FilterConfig {
 
 // Per route Configuration for the dynamic forward proxy HTTP filter.
 message PerRouteConfig {
-  // Indicates that before DNS lookup, the host header will be swapped with
-  // this value. If not set or empty, the original host header value
-  // will be used and no rewrite will happen.
-  string host_rewrite = 1;
+  oneof host_rewrite_specifier {
+    // Indicates that before DNS lookup, the host header will be swapped with
+    // this value. If not set or empty, the original host header value
+    // will be used and no rewrite will happen.
+    //
+    // Note: this rewrite affects both DNS lookup and host header forwarding. However, this
+    // option shouldn't be used with
+    // :ref:`HCM host rewrite <envoy_api_field_route.RouteAction.host_rewrite>` given that the
+    // value set here would be used for DNS lookups whereas the value set in the HCM would be used
+    // for host header forwarding which is not the desired outcome.
+    //
+    // [#next-major-version: host_rewrite_literal]
+    string host_rewrite = 1;
+
+    // Indicates that before DNS lookup, the host header will be swapped with
+    // the value of this header. If not set or empty, the original host header
+    // value will be used and no rewrite will happen.
+    //
+    // Note: this rewrite affects both DNS lookup and host header forwarding. However, this
+    // option shouldn't be used with
+    // :ref:`HCM host rewrite header <envoy_api_field_route.RouteAction.auto_host_rewrite_header>`
+    // given that the value set here would be used for DNS lookups whereas the value set in the HCM
+    // would be used for host header forwarding which is not the desired outcome.
+    //
+    // [#next-major-version: host_rewrite_header]
+    string auto_host_rewrite_header = 2;
+  }
 }

envoy/config/filter/http/dynamic_forward_proxy/v3alpha/dynamic_forward_proxy.proto

@@ -24,8 +24,32 @@ message FilterConfig {
 
 // Per route Configuration for the dynamic forward proxy HTTP filter.
 message PerRouteConfig {
-  // Indicates that before DNS lookup, the host header will be swapped with
-  // this value. If not set or empty, the original host header value
-  // will be used and no rewrite will happen.
-  string host_rewrite = 1;
+  oneof host_rewrite_specifier {
+    // Indicates that before DNS lookup, the host header will be swapped with
+    // this value. If not set or empty, the original host header value
+    // will be used and no rewrite will happen.
+    //
+    // Note: this rewrite affects both DNS lookup and host header forwarding. However, this
+    // option shouldn't be used with
+    // :ref:`HCM host rewrite <envoy_api_field_api.v3alpha.route.RouteAction.host_rewrite>` given
+    // that the value set here would be used for DNS lookups whereas the value set in the HCM would
+    // be used for host header forwarding which is not the desired outcome.
+    //
+    // [#next-major-version: host_rewrite_literal]
+    string host_rewrite = 1;
+
+    // Indicates that before DNS lookup, the host header will be swapped with
+    // the value of this header. If not set or empty, the original host header
+    // value will be used and no rewrite will happen.
+    //
+    // Note: this rewrite affects both DNS lookup and host header forwarding. However, this
+    // option shouldn't be used with
+    // :ref:`HCM host rewrite header
+    // <envoy_api_field_api.v3alpha.route.RouteAction.auto_host_rewrite_header>` given that the
+    // value set here would be used for DNS lookups whereas the value set in the HCM would be used
+    // for host header forwarding which is not the desired outcome.
+    //
+    // [#next-major-version: host_rewrite_header]
+    string auto_host_rewrite_header = 2;
+  }
 }