From 957478414028609b7becd3ccc2cddc5a4b13f442 Mon Sep 17 00:00:00 2001
From: Alexey Efimov <xeno@ydb.tech>
Date: Fri, 19 Jul 2024 12:11:56 +0000
Subject: [PATCH] http viewer capabilities

---
 ydb/core/viewer/json_handlers.h          |  4 +-
 ydb/core/viewer/json_handlers_viewer.cpp |  3 ++
 ydb/core/viewer/storage_groups.cpp       |  2 +-
 ydb/core/viewer/viewer.cpp               | 10 ++++
 ydb/core/viewer/viewer.h                 |  2 +
 ydb/core/viewer/viewer_capabilities.cpp  | 68 ++++++++++++++++++++++++
 ydb/core/viewer/ya.make                  |  1 +
 7 files changed, 88 insertions(+), 2 deletions(-)
 create mode 100644 ydb/core/viewer/viewer_capabilities.cpp

diff --git a/ydb/core/viewer/json_handlers.h b/ydb/core/viewer/json_handlers.h
index bfe329ad9385..0a994546740d 100644
--- a/ydb/core/viewer/json_handlers.h
+++ b/ydb/core/viewer/json_handlers.h
@@ -52,10 +52,12 @@ class TJsonHandler : public TJsonHandlerBase {
 struct TJsonHandlers {
     std::vector<TString> JsonHandlersList;
     THashMap<TString, std::shared_ptr<TJsonHandlerBase>> JsonHandlersIndex;
+    std::map<TString, int> Capabilities;
 
-    void AddHandler(const TString& name, TJsonHandlerBase* handler) {
+    void AddHandler(const TString& name, TJsonHandlerBase* handler, int version = 1) {
         JsonHandlersList.push_back(name);
         JsonHandlersIndex[name] = std::shared_ptr<TJsonHandlerBase>(handler);
+        Capabilities[name] = version;
     }
 
     TJsonHandlerBase* FindHandler(const TString& name) const {
diff --git a/ydb/core/viewer/json_handlers_viewer.cpp b/ydb/core/viewer/json_handlers_viewer.cpp
index ff55ada322b4..e037c4f4ea84 100644
--- a/ydb/core/viewer/json_handlers_viewer.cpp
+++ b/ydb/core/viewer/json_handlers_viewer.cpp
@@ -44,7 +44,10 @@
 
 namespace NKikimr::NViewer {
 
+void InitViewerCapabilitiesJsonHandler(TJsonHandlers& jsonHandlers);
+
 void InitViewerJsonHandlers(TJsonHandlers& jsonHandlers) {
+    InitViewerCapabilitiesJsonHandler(jsonHandlers);
     jsonHandlers.AddHandler("/viewer/nodelist", new TJsonHandler<TJsonNodeList>);
     jsonHandlers.AddHandler("/viewer/nodeinfo", new TJsonHandler<TJsonNodeInfo>);
     jsonHandlers.AddHandler("/viewer/sysinfo", new TJsonHandler<TJsonSysInfo>);
diff --git a/ydb/core/viewer/storage_groups.cpp b/ydb/core/viewer/storage_groups.cpp
index 2bdecfa14f4c..684f4a3eb596 100644
--- a/ydb/core/viewer/storage_groups.cpp
+++ b/ydb/core/viewer/storage_groups.cpp
@@ -1700,7 +1700,7 @@ YAML::Node TJsonRequestSwagger<TStorageGroups>::GetSwagger() {
     YAML::Node node = YAML::Load(R"___(
         post:
           tags:
-          - viewer
+          - storage
           summary: Storage groups
           description: Information about storage groups
           parameters:
diff --git a/ydb/core/viewer/viewer.cpp b/ydb/core/viewer/viewer.cpp
index 90f57b2495e8..779571ef32ea 100644
--- a/ydb/core/viewer/viewer.cpp
+++ b/ydb/core/viewer/viewer.cpp
@@ -355,6 +355,15 @@ class TViewer : public TActorBootstrapped<TViewer>, public IViewer {
         return {};
     }
 
+    NJson::TJsonValue GetCapabilities() override {
+        std::lock_guard guard(JsonHandlersMutex);
+        NJson::TJsonValue capabilities(NJson::JSON_MAP);
+        for (const auto& [name, version] : JsonHandlers.Capabilities) {
+            capabilities[name] = version;
+        }
+        return capabilities;
+    }
+
     void RegisterVirtualHandler(
             NKikimrViewer::EObjectType parentObjectType,
             TVirtualHandlerType handler) override {
@@ -385,6 +394,7 @@ class TViewer : public TActorBootstrapped<TViewer>, public IViewer {
 
 private:
     TJsonHandlers JsonHandlers;
+    std::mutex JsonHandlersMutex;
     std::unordered_map<TString, TString> Redirect307;
     const TKikimrRunConfig KikimrRunConfig;
     std::unordered_multimap<NKikimrViewer::EObjectType, TVirtualHandler> VirtualHandlersByParentType;
diff --git a/ydb/core/viewer/viewer.h b/ydb/core/viewer/viewer.h
index 912de93d668d..67cac550005c 100644
--- a/ydb/core/viewer/viewer.h
+++ b/ydb/core/viewer/viewer.h
@@ -206,6 +206,8 @@ class IViewer {
     virtual void AddRunningQuery(const TString& queryId, const TActorId& actorId) = 0;
     virtual void EndRunningQuery(const TString& queryId, const TActorId& actorId) = 0;
     virtual TActorId FindRunningQuery(const TString& queryId) = 0;
+
+    virtual NJson::TJsonValue GetCapabilities() = 0;
 };
 
 void SetupPQVirtualHandlers(IViewer* viewer);
diff --git a/ydb/core/viewer/viewer_capabilities.cpp b/ydb/core/viewer/viewer_capabilities.cpp
new file mode 100644
index 000000000000..42cb851971b3
--- /dev/null
+++ b/ydb/core/viewer/viewer_capabilities.cpp
@@ -0,0 +1,68 @@
+#include <unordered_map>
+#include <ydb/library/actors/core/actor_bootstrapped.h>
+#include <library/cpp/json/json_writer.h>
+#include "viewer.h"
+#include "json_handlers.h"
+#include "json_pipe_req.h"
+
+namespace NKikimr {
+namespace NViewer {
+
+using namespace NActors;
+
+class TViewerCapabilities : public TViewerPipeClient<TViewerCapabilities> {
+public:
+    using TBase = TViewerPipeClient<TViewerCapabilities>;
+
+    static constexpr NKikimrServices::TActivity::EType ActorActivityType() {
+        return NKikimrServices::TActivity::VIEWER_HANDLER;
+    }
+
+    TViewerCapabilities(IViewer* viewer, NMon::TEvHttpInfo::TPtr& ev)
+        : TBase(viewer, ev)
+    {}
+
+    void Bootstrap() {
+        ReplyAndPassAway();
+    }
+
+    void ReplyAndPassAway() {
+        NJson::TJsonValue json;
+        json["Capabilities"] = Viewer->GetCapabilities();
+        TBase::ReplyAndPassAway(GetHTTPOKJSON(NJson::WriteJson(json, false)));
+    }
+};
+
+template <>
+YAML::Node TJsonRequestSwagger<TViewerCapabilities>::GetSwagger() {
+    YAML::Node node = YAML::Load(R"___(
+        post:
+          tags:
+          - viewer
+          summary: Viewer capabilities
+          description: Viewer capabilities
+          responses:
+            200:
+              description: OK
+              content:
+                application/json:
+                  schema:
+                    type: object
+                    description: format depends on schema parameter
+            400:
+              description: Bad Request
+            403:
+              description: Forbidden
+            504:
+              description: Gateway Timeout
+            )___");
+    return node;
+}
+
+
+void InitViewerCapabilitiesJsonHandler(TJsonHandlers& jsonHandlers) {
+    jsonHandlers.AddHandler("/viewer/capabilities", new TJsonHandler<TViewerCapabilities>());
+}
+
+} // namespace NViewer
+} // namespace NKikimr
diff --git a/ydb/core/viewer/ya.make b/ydb/core/viewer/ya.make
index f1a37de383c9..1972ce9a31c9 100644
--- a/ydb/core/viewer/ya.make
+++ b/ydb/core/viewer/ya.make
@@ -70,6 +70,7 @@ SRCS(
     scheme_directory.h
     storage_groups.cpp
     query_autocomplete_helper.h
+    viewer_capabilities.cpp
     viewer_request.cpp
     viewer_request.h
     viewer.cpp