YT-23887: Support http proxies in discover_proxies handler

* Changelog entry
Type: feature
Component: proxy

Support HTTP proxies in `discover_proxies` handler
commit_hash:05fc624699785c3a54ec18f8d0a9f315d723f254

Author: savnadya

yt/yt/client/api/rpc_proxy/public.h

@@ -36,6 +36,10 @@ DEFINE_ENUM(EAddressType,
     ((InternalRpc)        (0))
     ((MonitoringHttp)     (1))
     ((TvmOnlyInternalRpc) (2))
+    ((Http)               (3))
+    ((Https)              (4))
+    ((TvmOnlyHttp)        (5))
+    ((TvmOnlyHttps)       (6))
 );
 
 ////////////////////////////////////////////////////////////////////////////////

yt/yt/client/driver/etc_commands.cpp

@@ -412,21 +412,31 @@ void TDiscoverProxiesCommand::Register(TRegistrar registrar)
         .Alias("type")
         .Default(EProxyKind::Rpc);
     registrar.Parameter("role", &TThis::Role)
-        .Default(DefaultRpcProxyRole);
+        .Optional();;
     registrar.Parameter("address_type", &TThis::AddressType)
-        .Default(NApi::NRpcProxy::DefaultAddressType);
+        .Optional();;
     registrar.Parameter("network_name", &TThis::NetworkName)
-        .Default(NApi::NRpcProxy::DefaultNetworkName);
+        .Default(NRpcProxy::DefaultNetworkName);
     registrar.Parameter("ignore_balancers", &TThis::IgnoreBalancers)
         .Default(false);
+
+    registrar.Postprocessor([] (TThis* config) {
+        if (config->Kind == EProxyKind::Http) {
+            config->Role = config->Role.value_or(DefaultHttpProxyRole);
+            config->AddressType = config->AddressType.value_or(NRpcProxy::EAddressType::Http);
+        } else {
+            config->Role = config->Role.value_or(DefaultRpcProxyRole);
+            config->AddressType = config->AddressType.value_or(NRpcProxy::DefaultAddressType);
+        }
+    });
 }
 
 void TDiscoverProxiesCommand::DoExecute(ICommandContextPtr context)
 {
     TProxyDiscoveryRequest request{
         .Kind = Kind,
-        .Role = Role,
-        .AddressType = AddressType,
+        .Role = Role.value_or(DefaultRpcProxyRole),
+        .AddressType = AddressType.value_or(NRpcProxy::DefaultAddressType),
         .NetworkName = NetworkName,
         .IgnoreBalancers = IgnoreBalancers,
     };

yt/yt/client/driver/etc_commands.h

@@ -231,8 +231,8 @@ class TDiscoverProxiesCommand
 
 private:
     NApi::EProxyKind Kind;
-    std::string Role;
-    NApi::NRpcProxy::EAddressType AddressType;
+    std::optional<std::string> Role;
+    std::optional<NApi::NRpcProxy::EAddressType> AddressType;
     std::string NetworkName;
     bool IgnoreBalancers;
 

yt/yt/client/driver/proxy_discovery_cache.cpp

@@ -157,7 +157,7 @@ class TProxyDiscoveryCache
                 if (address) {
                     response.Addresses.push_back(*address);
                 } else {
-                    // COMPAT(verytable): Drop it after all rpc proxies migrate to 22.3.
+                    // COMPAT(nadya73): Drop it after all http proxies migrate to 25.2.
                     if (!proxyNode->Attributes().Contains(AddressesAttributeName)) {
                         response.Addresses.push_back(proxyAddress);
                     }
@@ -175,6 +175,8 @@ class TProxyDiscoveryCache
                 return RpcProxiesPath;
             case EProxyKind::Grpc:
                 return GrpcProxiesPath;
+            case EProxyKind::Http:
+                return HttpProxiesPath;
             default:
                 THROW_ERROR_EXCEPTION("Proxy type %Qlv is not supported",
                     type);