filter: add network filters to the upstreams (#7503)

Signed-off-by: Kuat Yessenov <kuat@google.com>

Mirrored from https://github.com/envoyproxy/envoy @ 0f892c2385e7051d325d22b3f603cc60facedd6e

envoy/api/v2/BUILD

@@ -67,6 +67,7 @@ api_proto_library_internal(
         ":eds",
         "//envoy/api/v2/auth:cert",
         "//envoy/api/v2/cluster:circuit_breaker",
+        "//envoy/api/v2/cluster:filter",
         "//envoy/api/v2/cluster:outlier_detection",
         "//envoy/api/v2/core:address",
         "//envoy/api/v2/core:base",
@@ -86,6 +87,7 @@ api_go_grpc_library(
         ":eds_go_grpc",
         "//envoy/api/v2/auth:cert_go_proto",
         "//envoy/api/v2/cluster:circuit_breaker_go_proto",
+        "//envoy/api/v2/cluster:filter_go_proto",
         "//envoy/api/v2/cluster:outlier_detection_go_proto",
         "//envoy/api/v2/core:address_go_proto",
         "//envoy/api/v2/core:base_go_proto",

envoy/api/v2/cds.proto

@@ -16,6 +16,7 @@ import "envoy/api/v2/discovery.proto";
 import "envoy/api/v2/core/health_check.proto";
 import "envoy/api/v2/core/protocol.proto";
 import "envoy/api/v2/cluster/circuit_breaker.proto";
+import "envoy/api/v2/cluster/filter.proto";
 import "envoy/api/v2/cluster/outlier_detection.proto";
 import "envoy/api/v2/eds.proto";
 import "envoy/type/percent.proto";
@@ -51,7 +52,7 @@ service ClusterDiscoveryService {
 // [#protodoc-title: Clusters]
 
 // Configuration for a single upstream cluster.
-// [#comment:next free field: 40]
+// [#comment:next free field: 41]
 message Cluster {
   // Supplies the name of the cluster which must be unique across all clusters.
   // The cluster name is used when emitting
@@ -632,6 +633,11 @@ message Cluster {
   // If this flag is not set to true, Envoy will wait until the hosts fail active health
   // checking before removing it from the cluster.
   bool drain_connections_on_host_removal = 32;
+
+  // An optional list of network filters that make up the filter chain for
+  // outgoing connections made by the cluster. Order matters as the filters are
+  // processed sequentially as connection events happen.
+  repeated cluster.Filter filters = 40;
 }
 
 // An extensible structure containing the address Envoy should bind to when

envoy/api/v2/cluster/BUILD

@@ -33,3 +33,16 @@ api_go_proto_library(
     name = "outlier_detection",
     proto = ":outlier_detection",
 )
+
+api_proto_library_internal(
+    name = "filter",
+    srcs = ["filter.proto"],
+    visibility = [
+        "//envoy/api/v2:__pkg__",
+    ],
+)
+
+api_go_proto_library(
+    name = "filter",
+    proto = ":filter",
+)

envoy/api/v2/cluster/filter.proto

@@ -0,0 +1,30 @@
+syntax = "proto3";
+
+package envoy.api.v2.cluster;
+
+option java_outer_classname = "FilterProto";
+option java_multiple_files = true;
+option java_package = "io.envoyproxy.envoy.api.v2.cluster";
+option csharp_namespace = "Envoy.Api.V2.ClusterNS";
+option ruby_package = "Envoy.Api.V2.ClusterNS";
+
+import "google/protobuf/any.proto";
+import "google/protobuf/struct.proto";
+
+import "validate/validate.proto";
+import "gogoproto/gogo.proto";
+
+option (gogoproto.equal_all) = true;
+
+// [#protodoc-title: Upstream filters]
+//
+// Upstream filters apply to the connections to the upstream cluster hosts.
+message Filter {
+  // The name of the filter to instantiate. The name must match a
+  // :ref:`supported filter <config_network_filters>`.
+  string name = 1 [(validate.rules).string.min_bytes = 1];
+
+  // Filter specific configuration which depends on the filter being
+  // instantiated. See the supported filters for further documentation.
+  google.protobuf.Any typed_config = 2;
+}