loadbalancer: Add hostname support for ring hash and maglev (#10233)

Signed-off-by: Vivian Mathews <vivian.mathews@shopify.com>

Mirrored from https://github.com/envoyproxy/envoy @ 7f80d6346ed3367aca56a669789143433a02224a

envoy/api/v2/cluster.proto

@@ -354,7 +354,7 @@ message Cluster {
   }
 
   // Common configuration for all load balancer implementations.
-  // [#next-free-field: 7]
+  // [#next-free-field: 8]
   message CommonLbConfig {
     // Configuration for :ref:`zone aware routing
     // <arch_overview_load_balancing_zone_aware_routing>`.
@@ -384,6 +384,13 @@ message Cluster {
     message LocalityWeightedLbConfig {
     }
 
+    // Common Configuration for all consistent hashing load balancers (MaglevLb, RingHashLb, etc.)
+    message ConsistentHashingLbConfig {
+      // If set to `true`, the cluster will use hostname instead of the resolved
+      // address as the key to consistently hash to an upstream host. Only valid for StrictDNS clusters with hostnames which resolve to a single IP address.
+      bool use_hostname_for_hashing = 1;
+    }
+
     // Configures the :ref:`healthy panic threshold <arch_overview_load_balancing_panic_threshold>`.
     // If not specified, the default is 50%.
     // To disable panic mode, set to 0%.
@@ -438,6 +445,9 @@ message Cluster {
     // If set to `true`, the cluster manager will drain all existing
     // connections to upstream hosts whenever hosts are added or removed from the cluster.
     bool close_connections_on_host_set_change = 6;
+
+    //Common Configuration for all consistent hashing load balancers (MaglevLb, RingHashLb, etc.)
+    ConsistentHashingLbConfig consistent_hashing_lb_config = 7;
   }
 
   message RefreshRate {

envoy/config/cluster/v3/cluster.proto

@@ -373,7 +373,7 @@ message Cluster {
   }
 
   // Common configuration for all load balancer implementations.
-  // [#next-free-field: 7]
+  // [#next-free-field: 8]
   message CommonLbConfig {
     option (udpa.annotations.versioning).previous_message_type =
         "envoy.api.v2.Cluster.CommonLbConfig";
@@ -411,6 +411,16 @@ message Cluster {
           "envoy.api.v2.Cluster.CommonLbConfig.LocalityWeightedLbConfig";
     }
 
+    // Common Configuration for all consistent hashing load balancers (MaglevLb, RingHashLb, etc.)
+    message ConsistentHashingLbConfig {
+      option (udpa.annotations.versioning).previous_message_type =
+          "envoy.api.v2.Cluster.CommonLbConfig.ConsistentHashingLbConfig";
+
+      // If set to `true`, the cluster will use hostname instead of the resolved
+      // address as the key to consistently hash to an upstream host. Only valid for StrictDNS clusters with hostnames which resolve to a single IP address.
+      bool use_hostname_for_hashing = 1;
+    }
+
     // Configures the :ref:`healthy panic threshold <arch_overview_load_balancing_panic_threshold>`.
     // If not specified, the default is 50%.
     // To disable panic mode, set to 0%.
@@ -465,6 +475,9 @@ message Cluster {
     // If set to `true`, the cluster manager will drain all existing
     // connections to upstream hosts whenever hosts are added or removed from the cluster.
     bool close_connections_on_host_set_change = 6;
+
+    //Common Configuration for all consistent hashing load balancers (MaglevLb, RingHashLb, etc.)
+    ConsistentHashingLbConfig consistent_hashing_lb_config = 7;
   }
 
   message RefreshRate {