[4.0->main] prometheus on different port

plugins/http_plugin/http_plugin.cpp

@@ -28,14 +28,18 @@ namespace eosio {
    using std::regex;
    using boost::asio::ip::tcp;
    using std::shared_ptr;
-   
+
    static http_plugin_defaults current_http_plugin_defaults;
    static bool verbose_http_errors = false;
 
    void http_plugin::set_defaults(const http_plugin_defaults& config) {
       current_http_plugin_defaults = config;
    }
 
+   std::string http_plugin::get_server_header() {
+      return current_http_plugin_defaults.server_header;
+   }
+
    using http_plugin_impl_ptr = std::shared_ptr<class http_plugin_impl>;
 
    class http_plugin_impl : public std::enable_shared_from_this<http_plugin_impl> {
@@ -47,9 +51,9 @@ namespace eosio {
 
          http_plugin_impl& operator=(const http_plugin_impl&) = delete;
          http_plugin_impl& operator=(http_plugin_impl&&) = delete;
-         
+
          std::optional<tcp::endpoint>  listen_endpoint;
-         
+
          std::optional<asio::local::stream_protocol::endpoint> unix_endpoint;
 
          shared_ptr<beast_http_listener<plain_session, tcp, tcp_socket_t > >  beast_server;
@@ -272,7 +276,7 @@ namespace eosio {
 
          my->plugin_state->server_header = current_http_plugin_defaults.server_header;
 
-         
+
          //watch out for the returns above when adding new code here
       } FC_LOG_AND_RETHROW()
    }
@@ -309,7 +313,7 @@ namespace eosio {
             if(my->unix_endpoint) {
                try {
                   my->create_beast_server(true);
-                  
+
                   my->beast_unix_server->listen(*my->unix_endpoint);
                   my->beast_unix_server->start_accept();
                } catch ( const fc::exception& e ){
@@ -335,7 +339,7 @@ namespace eosio {
                   }
                }
             }}, appbase::exec_queue::read_only);
-            
+
          } catch (...) {
             fc_elog(logger(), "http_plugin startup fails, shutting down");
             app().quit();
@@ -457,9 +461,9 @@ namespace eosio {
    fc::microseconds http_plugin::get_max_response_time()const {
       return my->plugin_state->max_response_time;
    }
-   
+
    size_t http_plugin::get_max_body_size()const {
       return my->plugin_state->max_body_size;
    }
-   
+
 }

plugins/http_plugin/include/eosio/http_plugin/http_plugin.hpp

@@ -79,6 +79,7 @@ namespace eosio {
 
         //must be called before initialize
         static void set_defaults(const http_plugin_defaults& config);
+        static std::string get_server_header();
 
         APPBASE_PLUGIN_REQUIRES()
         void set_program_options(options_description&, options_description& cfg) override;
@@ -122,7 +123,7 @@ namespace eosio {
         void register_metrics_listener(chain::plugin_interface::metrics_listener listener);
 
         size_t get_max_body_size()const;
-      
+
    private:
         std::shared_ptr<class http_plugin_impl> my;
    };
@@ -176,7 +177,7 @@ namespace eosio {
    };
 
    /**
-    * @brief Used to trim whitespace from body. 
+    * @brief Used to trim whitespace from body.
     * Returned string_view valid only for lifetime of body
     */
    inline std::string_view make_trimmed_string_view(const std::string& body) {

plugins/prometheus_plugin/include/eosio/prometheus_plugin/simple_rest_server.hpp

@@ -0,0 +1,234 @@
+#pragma once
+
+#include <boost/beast/core.hpp>
+#include <boost/beast/http.hpp>
+#include <boost/beast/version.hpp>
+
+namespace eosio { namespace rest {
+
+   // The majority of the code here are derived from boost source
+   // libs/beast/example/http/server/async/http_server_async.cpp
+   // with minimum modification and yet reusable.
+
+   namespace beast = boost::beast;         // from <boost/beast.hpp>
+   namespace http  = beast::http;          // from <boost/beast/http.hpp>
+   namespace net   = boost::asio;          // from <boost/asio.hpp>
+   using tcp       = boost::asio::ip::tcp; // from <boost/asio/ip/tcp.hpp>
+   template <typename T>
+   class simple_server {
+      T* self() { return static_cast<T*>(this); }
+
+      void fail(beast::error_code ec, char const* what) { self()->log_error(what, ec.message()); }
+      // Return a response for the given request.
+      http::response<http::string_body> handle_request(http::request<http::string_body>&& req) {
+         auto server_header = self()->server_header();
+         // Returns a bad request response
+         auto const bad_request = [&req, &server_header](std::string_view why) {
+            http::response<http::string_body> res{ http::status::bad_request, req.version() };
+            res.set(http::field::server, server_header);
+            res.set(http::field::content_type, "text/plain");
+            res.keep_alive(req.keep_alive());
+            res.body() = std::string(why);
+            res.prepare_payload();
+            return res;
+         };
+
+         // Returns a not found response
+         auto const not_found = [&req, &server_header](std::string_view target) {
+            http::response<http::string_body> res{ http::status::not_found, req.version() };
+            res.set(http::field::server, server_header);
+            res.set(http::field::content_type, "text/plain");
+            res.keep_alive(req.keep_alive());
+            res.body() = "The resource '" + std::string(target) + "' was not found.";
+            res.prepare_payload();
+            return res;
+         };
+
+         // Returns a server error response
+         auto const server_error = [&req, &server_header](std::string_view what) {
+            http::response<http::string_body> res{ http::status::internal_server_error, req.version() };
+            res.set(http::field::server, server_header);
+            res.set(http::field::content_type, "text/plain");
+            res.keep_alive(req.keep_alive());
+            res.body() = "An error occurred: '" + std::string(what) + "'";
+            res.prepare_payload();
+            return res;
+         };
+
+         // Make sure we can handle the method
+         if (!self()->allow_method(req.method()))
+            return bad_request("Unknown HTTP-method");
+
+         // Request path must be absolute and not contain "..".
+         std::string_view target{req.target().data(), req.target().size()};
+         if (target.empty() || target[0] != '/' || target.find("..") != std::string_view::npos)
+            return bad_request("Illegal request-target");
+
+         try {
+            auto res = self()->on_request(std::move(req));
+            if (!res)
+               not_found(target);
+            return *res;
+         } catch (std::exception& ex) { return server_error(ex.what()); }
+      }
+
+      class session : public std::enable_shared_from_this<session> {
+         tcp::socket                                        socket_;
+         boost::asio::io_context::strand                    strand_;
+         beast::flat_buffer                                 buffer_;
+         http::request<http::string_body>                   req_;
+         simple_server*                                     server_;
+         std::shared_ptr<http::response<http::string_body>> res_;
+
+       public:
+         // Take ownership of the stream
+         session(net::io_context& ioc, tcp::socket&& socket, simple_server* server)
+             : socket_(std::move(socket)), strand_(ioc), server_(server) {}
+
+         // Start the asynchronous operation
+         void run() { do_read(); }
+
+         void do_read() {
+            // Make the request empty before reading,
+            // otherwise the operation behavior is undefined.
+            req_ = {};
+
+            // Read a request
+            http::async_read(
+                  socket_, buffer_, req_,
+                  boost::asio::bind_executor(strand_, [self = this->shared_from_this()](beast::error_code ec,
+                                                                                        std::size_t bytes_transferred) {
+                     self->on_read(ec, bytes_transferred);
+                  }));
+         }
+
+         void on_read(beast::error_code ec, std::size_t bytes_transferred) {
+            boost::ignore_unused(bytes_transferred);
+
+            // This means they closed the connection
+            if (ec == http::error::end_of_stream)
+               return do_close();
+
+            if (ec)
+               return server_->fail(ec, "read");
+
+            // Send the response
+            send_response(server_->handle_request(std::move(req_)));
+         }
+
+         void send_response(http::response<http::string_body>&& msg) {
+            // The lifetime of the message has to extend
+            // for the duration of the async operation so
+            // we use a shared_ptr to manage it.
+            res_ = std::make_shared<http::response<http::string_body>>(std::move(msg));
+
+            // Write the response
+            http::async_write(socket_, *res_,
+                              boost::asio::bind_executor(socket_.get_executor(),
+                                                         [self = this->shared_from_this(), close = res_->need_eof()](
+                                                               beast::error_code ec, std::size_t bytes_transferred) {
+                                                            self->on_write(ec, bytes_transferred, close);
+                                                         }));
+         }
+
+         void on_write(boost::system::error_code ec, std::size_t bytes_transferred, bool close) {
+            boost::ignore_unused(bytes_transferred);
+
+            if (ec)
+               return server_->fail(ec, "write");
+
+            if (close) {
+               // This means we should close the connection, usually because
+               // the response indicated the "Connection: close" semantic.
+               return do_close();
+            }
+
+            // We're done with the response so delete it
+            res_ = nullptr;
+
+            // Read another request
+            do_read();
+         }
+
+         void do_close() {
+            // Send a TCP shutdown
+            beast::error_code ec;
+            socket_.shutdown(tcp::socket::shutdown_send, ec);
+
+            // At this point the connection is closed gracefully
+         }
+      };
+
+      //------------------------------------------------------------------------------
+
+      // Accepts incoming connections and launches the sessions
+      class listener : public std::enable_shared_from_this<listener> {
+         net::io_context& ioc_;
+         tcp::acceptor    acceptor_;
+         tcp::socket      socket_;
+         simple_server*   server_;
+
+       public:
+         listener(net::io_context& ioc, tcp::endpoint endpoint, simple_server* server)
+             : ioc_(ioc), acceptor_(ioc), socket_(ioc), server_(server) {
+            boost::system::error_code ec;
+
+            // Open the acceptor
+            acceptor_.open(endpoint.protocol(), ec);
+            if (ec) {
+               server_->fail(ec, "open");
+               return;
+            }
+
+            // Allow address reuse
+            acceptor_.set_option(net::socket_base::reuse_address(true), ec);
+            if (ec) {
+               server_->fail(ec, "set_option");
+               return;
+            }
+
+            // Bind to the server address
+            acceptor_.bind(endpoint, ec);
+            if (ec) {
+               server_->fail(ec, "bind");
+               return;
+            }
+
+            // Start listening for connections
+            acceptor_.listen(net::socket_base::max_listen_connections, ec);
+            if (ec) {
+               server_->fail(ec, "listen");
+               return;
+            }
+         }
+
+         // Start accepting incoming connections
+         void run() {
+            if (!acceptor_.is_open())
+               return;
+            do_accept();
+         }
+
+       private:
+         void do_accept() {
+            acceptor_.async_accept(
+                  socket_, [self = this->shared_from_this()](boost::system::error_code ec) { self->on_accept(ec); });
+         }
+
+         void on_accept(boost::system::error_code ec) {
+            if (ec) {
+               server_->fail(ec, "accept");
+            } else {
+               // Create the session and run it
+               std::make_shared<session>(ioc_, std::move(socket_), server_)->run();
+            }
+
+            // Accept another connection
+            do_accept();
+         }
+      };
+
+    public:
+      void run(net::io_context& ioc, tcp::endpoint endpoint) { std::make_shared<listener>(ioc, endpoint, this)->run(); }
+   };
+}} // namespace eosio::rest