router: deprecate optional http filters and add route/vh level `is_optional` support in the typed_per_filter_config (#27263)

* router: remove optional http filters because it's hcm dependent

Signed-off-by: wbpcode <wangbaiping@corp.netease.com>

* Revert "router: remove optional http filters because it's hcm dependent"

This reverts commit 1725ce7d259d8586b0ba298e7e9a50953163fa73.

Signed-off-by: wbpcode <wangbaiping@corp.netease.com>

* add runtime guard/tests/change log

Signed-off-by: wbpcode <wangbaiping@corp.netease.com>

* fix more test

Signed-off-by: wbpcode <wangbaiping@corp.netease.com>

* add route/virual host level optional flag support and test and change log

Signed-off-by: wbpcode <wangbaiping@corp.netease.com>

* fix format

Signed-off-by: wbpcode <wangbaiping@corp.netease.com>

* fix docs

Signed-off-by: wbpcode <wangbaiping@corp.netease.com>

* fix test

Signed-off-by: wbpcode <wangbaiping@corp.netease.com>

* Update changelogs/current.yaml

Co-authored-by: Adi (Suissa) Peleg <adip@google.com>
Signed-off-by: code <wangbaiping@corp.netease.com>

* address all comments

Signed-off-by: wbpcode <wangbaiping@corp.netease.com>

* fix conflict

Signed-off-by: wbpcode <wangbaiping@corp.netease.com>

* address comment

Signed-off-by: wbpcode <wangbaiping@corp.netease.com>

* address comments

Signed-off-by: wbpcode <wangbaiping@corp.netease.com>

* fix test and add new test to cover the new exception throwing

Signed-off-by: wbpcode <wangbaiping@corp.netease.com>

---------

Signed-off-by: wbpcode <wangbaiping@corp.netease.com>
Signed-off-by: code <wangbaiping@corp.netease.com>
Co-authored-by: Adi (Suissa) Peleg <adip@google.com>

Mirrored from https://github.com/envoyproxy/envoy @ 9ecf7611bdace7d7ff77959fdb607b59012c6a6d

envoy/config/route/v3/route_components.proto

@@ -2376,7 +2376,6 @@ message InternalRedirectPolicy {
 // :ref:`Route.typed_per_filter_config<envoy_v3_api_field_config.route.v3.Route.typed_per_filter_config>`,
 // or :ref:`WeightedCluster.ClusterWeight.typed_per_filter_config<envoy_v3_api_field_config.route.v3.WeightedCluster.ClusterWeight.typed_per_filter_config>`
 // to add additional flags to the filter.
-// [#not-implemented-hide:]
 message FilterConfig {
   // The filter config.
   google.protobuf.Any config = 1;
@@ -2398,5 +2397,7 @@ message FilterConfig {
   //   created and it is too late to change the chain.
   //
   //   This field only make sense for the downstream HTTP filters for now.
+  //
+  // [#not-implemented-hide:]
   bool disabled = 3;
 }

envoy/extensions/filters/network/http_connection_manager/v3/http_connection_manager.proto

@@ -1145,7 +1145,6 @@ message HttpFilter {
   // If true, clients that do not support this filter may ignore the
   // filter but otherwise accept the config.
   // Otherwise, clients that do not support this filter must reject the config.
-  // This is also same with typed per filter config.
   bool is_optional = 6;
 }