feat: Graceful shutdown with old web server (#2786)

- Stop accepting connections during graceful shutdown in the old web server
- Stop all the services before Clio exits
- Move cache saving into stop callback

src/web/Server.hpp

@@ -34,6 +34,7 @@
 #include <boost/asio/ip/address.hpp>
 #include <boost/asio/ip/tcp.hpp>
 #include <boost/asio/socket_base.hpp>
+#include <boost/asio/spawn.hpp>
 #include <boost/asio/ssl/context.hpp>
 #include <boost/asio/ssl/error.hpp>
 #include <boost/asio/strand.hpp>
@@ -43,6 +44,7 @@
 #include <boost/beast/core/tcp_stream.hpp>
 #include <fmt/format.h>
 
+#include <atomic>
 #include <chrono>
 #include <cstdint>
 #include <exception>
@@ -221,7 +223,8 @@ template <
     template <typename> class PlainSessionType,
     template <typename> class SslSessionType,
     SomeServerHandler HandlerType>
-class Server : public std::enable_shared_from_this<Server<PlainSessionType, SslSessionType, HandlerType>> {
+class Server : public ServerTag,
+               public std::enable_shared_from_this<Server<PlainSessionType, SslSessionType, HandlerType>> {
     using std::enable_shared_from_this<Server<PlainSessionType, SslSessionType, HandlerType>>::shared_from_this;
 
     util::Logger log_{"WebServer"};
@@ -235,6 +238,7 @@ class Server : public std::enable_shared_from_this<Server<PlainSessionType, SslS
     std::shared_ptr<AdminVerificationStrategy> adminVerification_;
     std::uint32_t maxWsSendingQueueSize_;
     std::shared_ptr<ProxyIpResolver> proxyIpResolver_;
+    std::atomic_bool isStopped_{false};
 
 public:
     /**
@@ -308,6 +312,13 @@ public:
         doAccept();
     }
 
+    /** @brief Stop accepting new connections */
+    void
+    stop(boost::asio::yield_context)
+    {
+        isStopped_ = true;
+    }
+
 private:
     void
     doAccept()
@@ -321,6 +332,10 @@ private:
     void
     onAccept(boost::beast::error_code ec, tcp::socket socket)
     {
+        if (isStopped_) {
+            return;
+        }
+
         if (!ec) {
             auto ctxRef =
                 ctx_ ? std::optional<std::reference_wrapper<boost::asio::ssl::context>>{ctx_.value()} : std::nullopt;

src/web/interface/Concepts.hpp

@@ -22,6 +22,7 @@
 #include <boost/beast.hpp>
 #include <boost/beast/core/error.hpp>
 
+#include <concepts>
 #include <memory>
 #include <string>
 
@@ -39,4 +40,14 @@ concept SomeServerHandler =
         { handler(req, ws) };
     };
 
+/**
+ * @brief A tag class for server to help identify Server in templated code.
+ */
+struct ServerTag {
+    virtual ~ServerTag() = default;
+};
+
+template <typename T>
+concept SomeServer = std::derived_from<T, ServerTag>;
+
 }  // namespace web

src/web/ng/Server.hpp

@@ -23,6 +23,7 @@
 #include "util/config/ConfigDefinition.hpp"
 #include "util/log/Logger.hpp"
 #include "web/ProxyIpResolver.hpp"
+#include "web/interface/Concepts.hpp"
 #include "web/ng/Connection.hpp"
 #include "web/ng/MessageHandler.hpp"
 #include "web/ng/ProcessingPolicy.hpp"
@@ -34,7 +35,6 @@
 #include <boost/asio/spawn.hpp>
 #include <boost/asio/ssl/context.hpp>
 
-#include <concepts>
 #include <cstddef>
 #include <functional>
 #include <optional>
@@ -42,16 +42,6 @@
 
 namespace web::ng {
 
-/**
- * @brief A tag class for server to help identify Server in templated code.
- */
-struct ServerTag {
-    virtual ~ServerTag() = default;
-};
-
-template <typename T>
-concept SomeServer = std::derived_from<T, ServerTag>;
-
 /**
  * @brief Web server class.
  */