Adding proto changes for new pattern based url matching and rewriting (#21725)

Signed-off-by: silverstar195 <seanmaloney@google.com>

Mirrored from https://github.com/envoyproxy/envoy @ 7987ede6124572b46580cff6711737f85a69516c

envoy/config/route/v3/route_components.proto

@@ -482,7 +482,7 @@ message ClusterSpecifierPlugin {
   bool is_optional = 2;
 }
 
-// [#next-free-field: 15]
+// [#next-free-field: 16]
 message RouteMatch {
   option (udpa.annotations.versioning).previous_message_type = "envoy.api.v2.route.RouteMatch";
 
@@ -558,6 +558,35 @@ message RouteMatch {
     //
     // Expect the value to not contain ``?`` or ``#`` and not to end in ``/``
     string path_separated_prefix = 14 [(validate.rules).string = {pattern: "^[^?#]+[^?#/]$"}];
+
+    // If specified, the route is a template match rule meaning that the
+    // ``:path`` header (without the query string) must match the given
+    // ``path_template`` pattern.
+    //
+    // Path template matching types:
+    //
+    // * ``*`` : Matches a single path component, up to the next path separator: /
+    //
+    // * ``**`` : Matches zero or more path segments. If present, must be the last operator.
+    //
+    // * ``{name} or {name=*}`` :  A named variable matching one path segment up to the next path separator: /.
+    //
+    // * ``{name=videos/*}`` : A named variable matching more than one path segment.
+    //      The path component matching videos/* is captured as the named variable.
+    //
+    // * ``{name=**}`` : A named variable matching zero or more path segments.
+    //
+    //
+    // For example:
+    //
+    // * ``/videos/*/*/*.m4s`` would match ``videos/123414/hls/1080p5000_00001.m4s``
+    //
+    // * ``/videos/{file}`` would match ``/videos/1080p5000_00001.m4s``
+    //
+    // * ``/**.mpd`` would match ``/content/123/india/dash/55/manifest.mpd``
+    // [#not-implemented-hide:]
+    string path_template = 15
+        [(validate.rules).string = {min_len: 1 max_len: 256 ignore_empty: true}];
   }
 
   // Indicates that prefix/path matching should be case sensitive. The default
@@ -672,7 +701,7 @@ message CorsPolicy {
   core.v3.RuntimeFractionalPercent shadow_enabled = 10;
 }
 
-// [#next-free-field: 41]
+// [#next-free-field: 42]
 message RouteAction {
   option (udpa.annotations.versioning).previous_message_type = "envoy.api.v2.route.RouteAction";
 
@@ -1000,9 +1029,9 @@ message RouteAction {
   // place the original path before rewrite into the :ref:`x-envoy-original-path
   // <config_http_filters_router_x-envoy-original-path>` header.
   //
-  // Only one of *prefix_rewrite* or
-  // :ref:`regex_rewrite <envoy_v3_api_field_config.route.v3.RouteAction.regex_rewrite>`
-  // may be specified.
+  // Only one of :ref:`regex_rewrite <envoy_v3_api_field_config.route.v3.RouteAction.regex_rewrite>`
+  // [#comment:TODO(silverstar194) add the following once path_template_rewrite is implemented: :ref:`path_template_rewrite <envoy_v3_api_field_config.route.v3.RouteAction.path_template_rewrite>`]
+  // or *prefix_rewrite* may be specified.
   //
   // .. attention::
   //
@@ -1038,6 +1067,7 @@ message RouteAction {
   // <config_http_filters_router_x-envoy-original-path>` header.
   //
   // Only one of :ref:`prefix_rewrite <envoy_v3_api_field_config.route.v3.RouteAction.prefix_rewrite>`
+  // [#comment:TODO(silverstar194) add the following once path_template_rewrite is implemented: :ref:`path_template_rewrite <envoy_v3_api_field_config.route.v3.RouteAction.path_template_rewrite>`,]
   // or *regex_rewrite* may be specified.
   //
   // Examples using Google's `RE2 <https://github.com/google/re2>`_ engine:
@@ -1058,6 +1088,49 @@ message RouteAction {
   //   ``/aaa/yyy/bbb``.
   type.matcher.v3.RegexMatchAndSubstitute regex_rewrite = 32;
 
+  // Indicates that during forwarding, portions of the path that match the
+  // pattern should be rewritten, even allowing the substitution of variables
+  // from the match pattern into the new path as specified by the rewrite template.
+  // This is useful to allow application paths to be
+  // rewritten in a way that is aware of segments with variable content like
+  // identifiers. The router filter will place the original path as it was
+  // before the rewrite into the :ref:`x-envoy-original-path
+  // <config_http_filters_router_x-envoy-original-path>` header.
+  //
+  // Only one of :ref:`prefix_rewrite <envoy_v3_api_field_config.route.v3.RouteAction.prefix_rewrite>`,
+  // :ref:`regex_rewrite <envoy_v3_api_field_config.route.v3.RouteAction.regex_rewrite>`,
+  // or *path_template_rewrite* may be specified.
+  //
+  // Template pattern matching types:
+  //
+  // * ``*`` : Matches a single path component, up to the next path separator: /
+  //
+  // * ``**`` : Matches zero or more path segments. If present, must be the last operator.
+  //
+  // * ``{name} or {name=*}`` :  A named variable matching one path segment up to the next path separator: /.
+  //
+  // * ``{name=videos/*}`` : A named variable matching more than one path segment.
+  //      The path component matching videos/* is captured as the named variable.
+  //
+  // * ``{name=**}`` : A named variable matching zero or more path segments.
+  //
+  // Only named matches can be used to perform rewrites.
+  //
+  // Examples using path_template_rewrite:
+  //
+  // * The pattern ``/{one}/{two}`` paired with a substitution string of ``/{two}/{one}`` would
+  //   transform ``/cat/dog`` into ``/dog/cat``.
+  //
+  // * The pattern ``/videos/{language=lang/*}/*`` paired with a substitution string of
+  //   ``/{language}`` would transform ``/videos/lang/en/video.m4s`` into ``lang/en``.
+  //
+  // * The path pattern ``/content/{format}/{lang}/{id}/{file}.vtt`` paired with a substitution
+  //   string of ``/{lang}/{format}/{file}.vtt`` would transform ``/content/hls/en-us/12345/en_193913.vtt``
+  //   into ``/en-us/hls/en_193913.vtt``.
+  // [#not-implemented-hide:]
+  string path_template_rewrite = 41
+      [(validate.rules).string = {min_len: 1 max_len: 256 ignore_empty: true}];
+
   oneof host_rewrite_specifier {
     // Indicates that during forwarding, the host header will be swapped with
     // this value. Using this option will append the