[thrift_proxy] Add metadata_match to RouteAction and WeightedClusters (…

…#4402)

This change adds the ability to attach metadata to the clusters and weighted clusters to allow users to filter a down to instances that match metadata criteria provided. This is used only when the subset load balancer is enabled and leverages what exists already for http metadata matching.

Changes include:
- construct MetadataMatchCriteria objects from protobufs
- expose through Thrift::Router::RouteEntry and use in router impl

Risk Level: LOW
Testing: tests, new and old, pass
Docs Changes: added description for new proto fields. docs build successfully.
Release Notes: n/a

Signed-off-by: Brian Ramos <[email protected]>

api/envoy/config/filter/network/thrift_proxy/v2alpha1/route.proto

@@ -84,6 +84,14 @@ message RouteAction {
     // assigned to each cluster.
     WeightedCluster weighted_clusters = 2;
   }
+
+  // Optional endpoint metadata match criteria used by the subset load balancer. Only endpoints in
+  // the upstream cluster with metadata matching what is set in this field will be considered.
+  // Note that this will be merged with what's provided in :ref: `WeightedCluster.MetadataMatch
+  // <envoy_api_field_config.filter.network.thrift_proxy.v2alpha1.WeightedCluster.ClusterWeight.metadata_match>`,
+  // with values there taking precedence. Keys and values should be provided under the "envoy.lb"
+  // metadata key.
+  envoy.api.v2.core.Metadata metadata_match = 3;
 }
 
 // Allows for specification of multiple upstream clusters along with weights that indicate the
@@ -98,6 +106,14 @@ message WeightedCluster {
     // weight. The sum of weights across all entries in the clusters array determines the total
     // weight.
     google.protobuf.UInt32Value weight = 2 [(validate.rules).uint32.gte = 1];
+
+    // Optional endpoint metadata match criteria used by the subset load balancer. Only endpoints in
+    // the upstream cluster with metadata matching what is set in this field, combined with what's
+    // provided in :ref: `RouteAction's metadata_match
+    // <envoy_api_field_config.filter.network.thrift_proxy.v2alpha1.RouteAction.metadata_match>`,
+    // will be considered. Values here will take precedence. Keys and values should be provided
+    // under the "envoy.lb" metadata key.
+    envoy.api.v2.core.Metadata metadata_match = 3;
   }
 
   // Specifies one or more upstream clusters associated with the route.

source/extensions/filters/network/thrift_proxy/router/BUILD

@@ -27,6 +27,7 @@ envoy_cc_library(
     hdrs = ["router.h"],
     external_deps = ["abseil_optional"],
     deps = [
+        "//include/envoy/router:router_interface",
         "//source/extensions/filters/network/thrift_proxy:metadata_lib",
     ],
 )
@@ -43,6 +44,7 @@ envoy_cc_library(
         "//include/envoy/upstream:thread_local_cluster_interface",
         "//source/common/common:logger_lib",
         "//source/common/http:header_utility_lib",
+        "//source/common/router:metadatamatchcriteria_lib",
         "//source/common/upstream:load_balancer_lib",
         "//source/extensions/filters/network:well_known_names",
         "//source/extensions/filters/network/thrift_proxy:app_exception_lib",

source/extensions/filters/network/thrift_proxy/router/router.h

@@ -3,6 +3,8 @@
 #include <memory>
 #include <string>
 
+#include "envoy/router/router.h"
+
 #include "extensions/filters/network/thrift_proxy/metadata.h"
 
 namespace Envoy {
@@ -22,6 +24,12 @@ class RouteEntry {
    * @return const std::string& the upstream cluster that owns the route.
    */
   virtual const std::string& clusterName() const PURE;
+
+  /**
+   * @return MetadataMatchCriteria* the metadata that a subset load balancer should match when
+   * selecting an upstream host
+   */
+  virtual const Envoy::Router::MetadataMatchCriteria* metadataMatchCriteria() const PURE;
 };
 
 /**

source/extensions/filters/network/thrift_proxy/router/router_impl.cc

@@ -5,6 +5,7 @@
 #include "envoy/upstream/thread_local_cluster.h"
 
 #include "common/common/utility.h"
+#include "common/router/metadatamatchcriteria_impl.h"
 
 #include "extensions/filters/network/thrift_proxy/app_exception_impl.h"
 #include "extensions/filters/network/well_known_names.h"
@@ -22,12 +23,21 @@ RouteEntryImplBase::RouteEntryImplBase(
     config_headers_.push_back(header_map);
   }
 
+  if (route.route().has_metadata_match()) {
+    const auto filter_it = route.route().metadata_match().filter_metadata().find(
+        Envoy::Config::MetadataFilters::get().ENVOY_LB);
+    if (filter_it != route.route().metadata_match().filter_metadata().end()) {
+      metadata_match_criteria_.reset(
+          new Envoy::Router::MetadataMatchCriteriaImpl(filter_it->second));
+    }
+  }
+
   if (route.route().cluster_specifier_case() ==
       envoy::config::filter::network::thrift_proxy::v2alpha1::RouteAction::kWeightedClusters) {
 
     total_cluster_weight_ = 0UL;
     for (const auto& cluster : route.route().weighted_clusters().clusters()) {
-      std::unique_ptr<WeightedClusterEntry> cluster_entry(new WeightedClusterEntry(cluster));
+      std::unique_ptr<WeightedClusterEntry> cluster_entry(new WeightedClusterEntry(*this, cluster));
       weighted_clusters_.emplace_back(std::move(cluster_entry));
       total_cluster_weight_ += weighted_clusters_.back()->clusterWeight();
     }
@@ -69,10 +79,25 @@ bool RouteEntryImplBase::headersMatch(const Http::HeaderMap& headers) const {
 }
 
 RouteEntryImplBase::WeightedClusterEntry::WeightedClusterEntry(
+    const RouteEntryImplBase& parent,
     const envoy::config::filter::network::thrift_proxy::v2alpha1::WeightedCluster_ClusterWeight&
         cluster)
-    : cluster_name_(cluster.name()),
-      cluster_weight_(PROTOBUF_GET_WRAPPED_REQUIRED(cluster, weight)) {}
+    : parent_(parent), cluster_name_(cluster.name()),
+      cluster_weight_(PROTOBUF_GET_WRAPPED_REQUIRED(cluster, weight)) {
+  if (cluster.has_metadata_match()) {
+    const auto filter_it = cluster.metadata_match().filter_metadata().find(
+        Envoy::Config::MetadataFilters::get().ENVOY_LB);
+    if (filter_it != cluster.metadata_match().filter_metadata().end()) {
+      if (parent.metadata_match_criteria_) {
+        metadata_match_criteria_ =
+            parent.metadata_match_criteria_->mergeMatchCriteria(filter_it->second);
+      } else {
+        metadata_match_criteria_.reset(
+            new Envoy::Router::MetadataMatchCriteriaImpl(filter_it->second));
+      }
+    }
+  }
+}
 
 MethodNameRouteEntryImpl::MethodNameRouteEntryImpl(
     const envoy::config::filter::network::thrift_proxy::v2alpha1::Route& route)

source/extensions/filters/network/thrift_proxy/router/router_impl.h

@@ -5,6 +5,7 @@
 #include <vector>
 
 #include "envoy/config/filter/network/thrift_proxy/v2alpha1/thrift_proxy.pb.h"
+#include "envoy/router/router.h"
 #include "envoy/tcp/conn_pool.h"
 #include "envoy/upstream/load_balancer.h"
 
@@ -34,6 +35,10 @@ class RouteEntryImplBase : public RouteEntry,
   // Router::RouteEntry
   const std::string& clusterName() const override;
 
+  const Envoy::Router::MetadataMatchCriteria* metadataMatchCriteria() const override {
+    return metadata_match_criteria_.get();
+  }
+
   // Router::Route
   const RouteEntry* routeEntry() const override;
 
@@ -48,27 +53,38 @@ class RouteEntryImplBase : public RouteEntry,
   class WeightedClusterEntry : public RouteEntry, public Route {
   public:
     WeightedClusterEntry(
+        const RouteEntryImplBase& parent,
         const envoy::config::filter::network::thrift_proxy::v2alpha1::WeightedCluster_ClusterWeight&
             cluster);
 
     uint64_t clusterWeight() const { return cluster_weight_; }
 
     // Router::RouteEntry
     const std::string& clusterName() const override { return cluster_name_; }
+    const Envoy::Router::MetadataMatchCriteria* metadataMatchCriteria() const override {
+      if (metadata_match_criteria_) {
+        return metadata_match_criteria_.get();
+      }
+
+      return parent_.metadataMatchCriteria();
+    }
 
     // Router::Route
     const RouteEntry* routeEntry() const override { return this; }
 
   private:
+    const RouteEntryImplBase& parent_;
     const std::string cluster_name_;
     const uint64_t cluster_weight_;
+    Envoy::Router::MetadataMatchCriteriaConstPtr metadata_match_criteria_;
   };
   typedef std::shared_ptr<WeightedClusterEntry> WeightedClusterEntrySharedPtr;
 
   const std::string cluster_name_;
   std::vector<Http::HeaderUtility::HeaderData> config_headers_;
   std::vector<WeightedClusterEntrySharedPtr> weighted_clusters_;
   uint64_t total_cluster_weight_;
+  Envoy::Router::MetadataMatchCriteriaConstPtr metadata_match_criteria_;
 };
 
 typedef std::shared_ptr<const RouteEntryImplBase> RouteEntryImplBaseConstSharedPtr;
@@ -138,6 +154,12 @@ class Router : public Tcp::ConnectionPool::UpstreamCallbacks,
 
   // Upstream::LoadBalancerContext
   const Network::Connection* downstreamConnection() const override;
+  const Envoy::Router::MetadataMatchCriteria* metadataMatchCriteria() override {
+    if (route_entry_) {
+      return route_entry_->metadataMatchCriteria();
+    }
+    return nullptr;
+  }
 
   // Tcp::ConnectionPool::UpstreamCallbacks
   void onUpstreamData(Buffer::Instance& data, bool end_stream) override;

test/extensions/filters/network/thrift_proxy/BUILD

@@ -263,6 +263,7 @@ envoy_extension_cc_test(
     deps = [
         ":utility_lib",
         "//source/extensions/filters/network/thrift_proxy/router:config",
+        "//source/extensions/filters/network/thrift_proxy/router:router_interface",
         "//source/extensions/filters/network/thrift_proxy/router:router_lib",
         "//test/test_common:utility_lib",
     ],

test/extensions/filters/network/thrift_proxy/mocks.h

@@ -1,5 +1,7 @@
 #pragma once
 
+#include "envoy/router/router.h"
+
 #include "extensions/filters/network/thrift_proxy/conn_manager.h"
 #include "extensions/filters/network/thrift_proxy/conn_state.h"
 #include "extensions/filters/network/thrift_proxy/filters/filter.h"
@@ -239,6 +241,7 @@ class MockRouteEntry : public RouteEntry {
 
   // ThriftProxy::Router::RouteEntry
   MOCK_CONST_METHOD0(clusterName, const std::string&());
+  MOCK_CONST_METHOD0(metadataMatchCriteria, const Envoy::Router::MetadataMatchCriteria*());
 };
 
 class MockRoute : public Route {