http/http_client.hpp - openbmc/bmcweb - Gitiles

 /*
 // Copyright (c) 2020 Intel Corporation
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
 // You may obtain a copy of the License at
 //
 //      http://www.apache.org/licenses/LICENSE-2.0
 //
 // Unless required by applicable law or agreed to in writing, software
 // distributed under the License is distributed on an "AS IS" BASIS,
 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 // See the License for the specific language governing permissions and
 // limitations under the License.
 */
 #pragma once
 #include <boost/asio/strand.hpp>
 #include <boost/beast/core.hpp>
 #include <boost/beast/http.hpp>
 #include <boost/beast/version.hpp>

 #include <cstdlib>
 #include <functional>
 #include <iostream>
 #include <memory>
 #include <queue>
 #include <string>

 namespace crow
 {

 static constexpr uint8_t maxRequestQueueSize = 50;

 enum class ConnState
 {
     initialized,
     connectInProgress,
     connectFailed,
     connected,
     sendInProgress,
     sendFailed,
     recvFailed,
     idle,
     suspended,
     closed,
     terminated
 };

 class HttpClient : public std::enable_shared_from_this<HttpClient>
 {
   private:
     boost::beast::tcp_stream conn;
     boost::asio::steady_timer timer;
     boost::beast::flat_buffer buffer;
     boost::beast::http::request<boost::beast::http::string_body> req;
     boost::beast::http::response<boost::beast::http::string_body> res;
     boost::asio::ip::tcp::resolver::results_type endpoint;
     std::vector<std::pair<std::string, std::string>> headers;
     std::queue<std::string> requestDataQueue;
     ConnState state;
     std::string subId;
     std::string host;
     std::string port;
     std::string uri;
     uint32_t retryCount;
     uint32_t maxRetryAttempts;
     uint32_t retryIntervalSecs;
     std::string retryPolicyAction;
     bool runningTimer;

     void doConnect()
     {
         if (state == ConnState::connectInProgress)
         {
             return;
         }
         state = ConnState::connectInProgress;

         BMCWEB_LOG_DEBUG << "Trying to connect to: " << host << ":" << port;
         // Set a timeout on the operation
         conn.expires_after(std::chrono::seconds(30));
         conn.async_connect(endpoint, [self(shared_from_this())](
                                          const boost::beast::error_code& ec,
                                          const boost::asio::ip::tcp::resolver::
                                              results_type::endpoint_type& ep) {
             if (ec)
             {
                 BMCWEB_LOG_ERROR << "Connect " << ep
                                  << " failed: " << ec.message();
                 self->state = ConnState::connectFailed;
                 self->checkQueue();
                 return;
             }
             self->state = ConnState::connected;
             BMCWEB_LOG_DEBUG << "Connected to: " << ep;

             self->checkQueue();
         });
     }

     void sendMessage(const std::string& data)
     {
         if (state == ConnState::sendInProgress)
         {
             return;
         }
         state = ConnState::sendInProgress;

         BMCWEB_LOG_DEBUG << __FUNCTION__ << "(): " << host << ":" << port;

         req.version(static_cast<int>(11)); // HTTP 1.1
         req.target(uri);
         req.method(boost::beast::http::verb::post);

         // Set headers
         for (const auto& [key, value] : headers)
         {
             req.set(key, value);
         }
         req.set(boost::beast::http::field::host, host);
         req.keep_alive(true);

         req.body() = data;
         req.prepare_payload();

         // Set a timeout on the operation
         conn.expires_after(std::chrono::seconds(30));

         // Send the HTTP request to the remote host
         boost::beast::http::async_write(
             conn, req,
             [self(shared_from_this())](const boost::beast::error_code& ec,
                                        const std::size_t& bytesTransferred) {
                 if (ec)
                 {
                     BMCWEB_LOG_ERROR << "sendMessage() failed: "
                                      << ec.message();
                     self->state = ConnState::sendFailed;
                     self->checkQueue();
                     return;
                 }
                 BMCWEB_LOG_DEBUG << "sendMessage() bytes transferred: "
                                  << bytesTransferred;
                 boost::ignore_unused(bytesTransferred);

                 self->recvMessage();
             });
     }

     void recvMessage()
     {
         // Receive the HTTP response
         boost::beast::http::async_read(
             conn, buffer, res,
             [self(shared_from_this())](const boost::beast::error_code& ec,
                                        const std::size_t& bytesTransferred) {
                 if (ec)
                 {
                     BMCWEB_LOG_ERROR << "recvMessage() failed: "
                                      << ec.message();
                     self->state = ConnState::recvFailed;
                     self->checkQueue();
                     return;
                 }
                 BMCWEB_LOG_DEBUG << "recvMessage() bytes transferred: "
                                  << bytesTransferred;
                 boost::ignore_unused(bytesTransferred);

                 // Discard received data. We are not interested.
                 BMCWEB_LOG_DEBUG << "recvMessage() data: " << self->res;

                 // Send is successful, Lets remove data from queue
                 // check for next request data in queue.
                 self->requestDataQueue.pop();
                 self->state = ConnState::idle;
                 self->checkQueue();
             });
     }

     void doClose()
     {
         boost::beast::error_code ec;
         conn.socket().shutdown(boost::asio::ip::tcp::socket::shutdown_both, ec);

         state = ConnState::closed;
         // not_connected happens sometimes so don't bother reporting it.
         if (ec && ec != boost::beast::errc::not_connected)
         {
             BMCWEB_LOG_ERROR << "shutdown failed: " << ec.message();
             return;
         }
         BMCWEB_LOG_DEBUG << "Connection closed gracefully";
     }

     void checkQueue(const bool newRecord = false)
     {
         if (requestDataQueue.empty())
         {
             // TODO: Having issue in keeping connection alive. So lets close if
             // nothing to be trasferred.
             doClose();

             BMCWEB_LOG_DEBUG << "requestDataQueue is empty\n";
             return;
         }

         if (retryCount >= maxRetryAttempts)
         {
             BMCWEB_LOG_ERROR << "Maximum number of retries is reached.";

             // Clear queue.
             while (!requestDataQueue.empty())
             {
                 requestDataQueue.pop();
             }

             BMCWEB_LOG_DEBUG << "Retry policy is set to " << retryPolicyAction;
             if (retryPolicyAction == "TerminateAfterRetries")
             {
                 // TODO: delete subscription
                 state = ConnState::terminated;
                 return;
             }
             else if (retryPolicyAction == "SuspendRetries")
             {
                 state = ConnState::suspended;
                 return;
             }
             else
             {
                 // keep retrying, reset count and continue.
                 retryCount = 0;
             }
         }

         if ((state == ConnState::connectFailed) ||
             (state == ConnState::sendFailed) ||
             (state == ConnState::recvFailed))
         {
             if (newRecord)
             {
                 // We are already running async wait and retry.
                 // Since record is added to queue, it gets the
                 // turn in FIFO.
                 return;
             }

             if (runningTimer)
             {
                 BMCWEB_LOG_DEBUG << "Retry timer is already running.";
                 return;
             }
             runningTimer = true;

             retryCount++;

             BMCWEB_LOG_DEBUG << "Attempt retry after " << retryIntervalSecs
                              << " seconds. RetryCount = " << retryCount;
             timer.expires_after(std::chrono::seconds(retryIntervalSecs));
             timer.async_wait([self = shared_from_this()](
                                  const boost::system::error_code& ec) {
                 self->runningTimer = false;
                 self->connStateCheck();
             });
             return;
         }
         else
         {
             // reset retry count.
             retryCount = 0;
         }
         connStateCheck();

         return;
     }

     void connStateCheck()
     {
         switch (state)
         {
             case ConnState::connectInProgress:
             case ConnState::sendInProgress:
             case ConnState::suspended:
             case ConnState::terminated:
                 // do nothing
                 break;
             case ConnState::initialized:
             case ConnState::closed:
             case ConnState::connectFailed:
             case ConnState::sendFailed:
             case ConnState::recvFailed:
             {
                 // After establishing the connection, checkQueue() will
                 // get called and it will attempt to send data.
                 doConnect();
                 break;
             }
             case ConnState::connected:
             case ConnState::idle:
             {
                 std::string data = requestDataQueue.front();
                 sendMessage(data);
                 break;
             }
             default:
                 break;
         }
     }

   public:
     explicit HttpClient(boost::asio::io_context& ioc, const std::string& id,
                         const std::string& destIP, const std::string& destPort,
                         const std::string& destUri) :
         conn(ioc),
         timer(ioc), subId(id), host(destIP), port(destPort), uri(destUri),
         retryCount(0), maxRetryAttempts(5),
         retryPolicyAction("TerminateAfterRetries"), runningTimer(false)
     {
         boost::asio::ip::tcp::resolver resolver(ioc);
         endpoint = resolver.resolve(host, port);
         state = ConnState::initialized;
     }

     void sendData(const std::string& data)
     {
         if (state == ConnState::suspended)
         {
             return;
         }

         if (requestDataQueue.size() <= maxRequestQueueSize)
         {
             requestDataQueue.push(data);
             checkQueue(true);
         }
         else
         {
             BMCWEB_LOG_ERROR << "Request queue is full. So ignoring data.";
         }

         return;
     }

     void setHeaders(
         const std::vector<std::pair<std::string, std::string>>& httpHeaders)
     {
         headers = httpHeaders;
     }

     void setRetryConfig(const uint32_t retryAttempts,
                         const uint32_t retryTimeoutInterval)
     {
         maxRetryAttempts = retryAttempts;
         retryIntervalSecs = retryTimeoutInterval;
     }

     void setRetryPolicy(const std::string& retryPolicy)
     {
         retryPolicyAction = retryPolicy;
     }
 };

 } // namespace crow
	/*
	// Copyright (c) 2020 Intel Corporation
	//
	// Licensed under the Apache License, Version 2.0 (the "License");
	// you may not use this file except in compliance with the License.
	// You may obtain a copy of the License at
	//
	// http://www.apache.org/licenses/LICENSE-2.0
	//
	// Unless required by applicable law or agreed to in writing, software
	// distributed under the License is distributed on an "AS IS" BASIS,
	// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	// See the License for the specific language governing permissions and
	// limitations under the License.
	*/
	#pragma once
	#include <boost/asio/strand.hpp>
	#include <boost/beast/core.hpp>
	#include <boost/beast/http.hpp>
	#include <boost/beast/version.hpp>

	#include <cstdlib>
	#include <functional>
	#include <iostream>
	#include <memory>
	#include <queue>
	#include <string>

	namespace crow
	{

	static constexpr uint8_t maxRequestQueueSize = 50;

	enum class ConnState
	{
	initialized,
	connectInProgress,
	connectFailed,
	connected,
	sendInProgress,
	sendFailed,
	recvFailed,
	idle,
	suspended,
	closed,
	terminated
	};

	class HttpClient : public std::enable_shared_from_this<HttpClient>
	{
	private:
	boost::beast::tcp_stream conn;
	boost::asio::steady_timer timer;
	boost::beast::flat_buffer buffer;
	boost::beast::http::request<boost::beast::http::string_body> req;
	boost::beast::http::response<boost::beast::http::string_body> res;
	boost::asio::ip::tcp::resolver::results_type endpoint;
	std::vector<std::pair<std::string, std::string>> headers;
	std::queue<std::string> requestDataQueue;
	ConnState state;
	std::string subId;
	std::string host;
	std::string port;
	std::string uri;
	uint32_t retryCount;
	uint32_t maxRetryAttempts;
	uint32_t retryIntervalSecs;
	std::string retryPolicyAction;
	bool runningTimer;

	void doConnect()
	{
	if (state == ConnState::connectInProgress)
	{
	return;
	}
	state = ConnState::connectInProgress;

	BMCWEB_LOG_DEBUG << "Trying to connect to: " << host << ":" << port;
	// Set a timeout on the operation
	conn.expires_after(std::chrono::seconds(30));
	conn.async_connect(endpoint, [self(shared_from_this())](
	const boost::beast::error_code& ec,
	const boost::asio::ip::tcp::resolver::
	results_type::endpoint_type& ep) {
	if (ec)
	{
	BMCWEB_LOG_ERROR << "Connect " << ep
	<< " failed: " << ec.message();
	self->state = ConnState::connectFailed;
	self->checkQueue();
	return;
	}
	self->state = ConnState::connected;
	BMCWEB_LOG_DEBUG << "Connected to: " << ep;

	self->checkQueue();
	});
	}

	void sendMessage(const std::string& data)
	{
	if (state == ConnState::sendInProgress)
	{
	return;
	}
	state = ConnState::sendInProgress;

	BMCWEB_LOG_DEBUG << __FUNCTION__ << "(): " << host << ":" << port;

	req.version(static_cast<int>(11)); // HTTP 1.1
	req.target(uri);
	req.method(boost::beast::http::verb::post);

	// Set headers
	for (const auto& [key, value] : headers)
	{
	req.set(key, value);
	}
	req.set(boost::beast::http::field::host, host);
	req.keep_alive(true);

	req.body() = data;
	req.prepare_payload();

	// Set a timeout on the operation
	conn.expires_after(std::chrono::seconds(30));

	// Send the HTTP request to the remote host
	boost::beast::http::async_write(
	conn, req,
	[self(shared_from_this())](const boost::beast::error_code& ec,
	const std::size_t& bytesTransferred) {
	if (ec)
	{
	BMCWEB_LOG_ERROR << "sendMessage() failed: "
	<< ec.message();
	self->state = ConnState::sendFailed;
	self->checkQueue();
	return;
	}
	BMCWEB_LOG_DEBUG << "sendMessage() bytes transferred: "
	<< bytesTransferred;
	boost::ignore_unused(bytesTransferred);

	self->recvMessage();
	});
	}

	void recvMessage()
	{
	// Receive the HTTP response
	boost::beast::http::async_read(
	conn, buffer, res,
	[self(shared_from_this())](const boost::beast::error_code& ec,
	const std::size_t& bytesTransferred) {
	if (ec)
	{
	BMCWEB_LOG_ERROR << "recvMessage() failed: "
	<< ec.message();
	self->state = ConnState::recvFailed;
	self->checkQueue();
	return;
	}
	BMCWEB_LOG_DEBUG << "recvMessage() bytes transferred: "
	<< bytesTransferred;
	boost::ignore_unused(bytesTransferred);

	// Discard received data. We are not interested.
	BMCWEB_LOG_DEBUG << "recvMessage() data: " << self->res;

	// Send is successful, Lets remove data from queue
	// check for next request data in queue.
	self->requestDataQueue.pop();
	self->state = ConnState::idle;
	self->checkQueue();
	});
	}

	void doClose()
	{
	boost::beast::error_code ec;
	conn.socket().shutdown(boost::asio::ip::tcp::socket::shutdown_both, ec);

	state = ConnState::closed;
	// not_connected happens sometimes so don't bother reporting it.
	if (ec && ec != boost::beast::errc::not_connected)
	{
	BMCWEB_LOG_ERROR << "shutdown failed: " << ec.message();
	return;
	}
	BMCWEB_LOG_DEBUG << "Connection closed gracefully";
	}

	void checkQueue(const bool newRecord = false)
	{
	if (requestDataQueue.empty())
	{
	// TODO: Having issue in keeping connection alive. So lets close if
	// nothing to be trasferred.
	doClose();

	BMCWEB_LOG_DEBUG << "requestDataQueue is empty\n";
	return;
	}

	if (retryCount >= maxRetryAttempts)
	{
	BMCWEB_LOG_ERROR << "Maximum number of retries is reached.";

	// Clear queue.
	while (!requestDataQueue.empty())
	{
	requestDataQueue.pop();
	}

	BMCWEB_LOG_DEBUG << "Retry policy is set to " << retryPolicyAction;
	if (retryPolicyAction == "TerminateAfterRetries")
	{
	// TODO: delete subscription
	state = ConnState::terminated;
	return;
	}
	else if (retryPolicyAction == "SuspendRetries")
	{
	state = ConnState::suspended;
	return;
	}
	else
	{
	// keep retrying, reset count and continue.
	retryCount = 0;
	}
	}

	if ((state == ConnState::connectFailed) \|\|
	(state == ConnState::sendFailed) \|\|
	(state == ConnState::recvFailed))
	{
	if (newRecord)
	{
	// We are already running async wait and retry.
	// Since record is added to queue, it gets the
	// turn in FIFO.
	return;
	}

	if (runningTimer)
	{
	BMCWEB_LOG_DEBUG << "Retry timer is already running.";
	return;
	}
	runningTimer = true;

	retryCount++;

	BMCWEB_LOG_DEBUG << "Attempt retry after " << retryIntervalSecs
	<< " seconds. RetryCount = " << retryCount;
	timer.expires_after(std::chrono::seconds(retryIntervalSecs));
	timer.async_wait([self = shared_from_this()](
	const boost::system::error_code& ec) {
	self->runningTimer = false;
	self->connStateCheck();
	});
	return;
	}
	else
	{
	// reset retry count.
	retryCount = 0;
	}
	connStateCheck();

	return;
	}

	void connStateCheck()
	{
	switch (state)
	{
	case ConnState::connectInProgress:
	case ConnState::sendInProgress:
	case ConnState::suspended:
	case ConnState::terminated:
	// do nothing
	break;
	case ConnState::initialized:
	case ConnState::closed:
	case ConnState::connectFailed:
	case ConnState::sendFailed:
	case ConnState::recvFailed:
	{
	// After establishing the connection, checkQueue() will
	// get called and it will attempt to send data.
	doConnect();
	break;
	}
	case ConnState::connected:
	case ConnState::idle:
	{
	std::string data = requestDataQueue.front();
	sendMessage(data);
	break;
	}
	default:
	break;
	}
	}

	public:
	explicit HttpClient(boost::asio::io_context& ioc, const std::string& id,
	const std::string& destIP, const std::string& destPort,
	const std::string& destUri) :
	conn(ioc),
	timer(ioc), subId(id), host(destIP), port(destPort), uri(destUri),
	retryCount(0), maxRetryAttempts(5),
	retryPolicyAction("TerminateAfterRetries"), runningTimer(false)
	{
	boost::asio::ip::tcp::resolver resolver(ioc);
	endpoint = resolver.resolve(host, port);
	state = ConnState::initialized;
	}

	void sendData(const std::string& data)
	{
	if (state == ConnState::suspended)
	{
	return;
	}

	if (requestDataQueue.size() <= maxRequestQueueSize)
	{
	requestDataQueue.push(data);
	checkQueue(true);
	}
	else
	{
	BMCWEB_LOG_ERROR << "Request queue is full. So ignoring data.";
	}

	return;
	}

	void setHeaders(
	const std::vector<std::pair<std::string, std::string>>& httpHeaders)
	{
	headers = httpHeaders;
	}

	void setRetryConfig(const uint32_t retryAttempts,
	const uint32_t retryTimeoutInterval)
	{
	maxRetryAttempts = retryAttempts;
	retryIntervalSecs = retryTimeoutInterval;
	}

	void setRetryPolicy(const std::string& retryPolicy)
	{
	retryPolicyAction = retryPolicy;
	}
	};

	} // namespace crow