From d14582a1d92e036780166a0b5ec0494d7353cc75 Mon Sep 17 00:00:00 2001
From: Roland Reichwein <mail@reichwein.it>
Date: Fri, 13 Jan 2023 16:20:42 +0100
Subject: Implemented and tested managed FCGI application start, separated out
 process check functions to libreichwein

---
 plugins/fcgi/fastcgiprocess.cpp | 151 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 151 insertions(+)
 create mode 100644 plugins/fcgi/fastcgiprocess.cpp

(limited to 'plugins/fcgi/fastcgiprocess.cpp')

diff --git a/plugins/fcgi/fastcgiprocess.cpp b/plugins/fcgi/fastcgiprocess.cpp
new file mode 100644
index 0000000..dd51583
--- /dev/null
+++ b/plugins/fcgi/fastcgiprocess.cpp
@@ -0,0 +1,151 @@
+#include "fastcgiprocess.h"
+
+#include <chrono>
+#include <filesystem>
+#include <iostream>
+#include <string>
+#include <thread>
+
+#include <boost/algorithm/string.hpp>
+#include <boost/beast/core.hpp>
+#include <boost/beast/http.hpp>
+#include <boost/beast/websocket.hpp>
+#include <boost/beast/websocket/ssl.hpp>
+#include <boost/beast/ssl.hpp>
+#include <boost/beast/version.hpp>
+#include <boost/asio/buffer.hpp>
+#include <boost/asio/buffers_iterator.hpp>
+#include <boost/asio/connect.hpp>
+#include <boost/asio/ip/tcp.hpp>
+#include <boost/asio/ssl/error.hpp>
+#include <boost/asio/ssl/stream.hpp>
+#include <boost/property_tree/ptree.hpp>
+#include <boost/property_tree/xml_parser.hpp>
+#include <boost/asio/local/stream_protocol.hpp>
+
+#include <signal.h>
+#include <sys/wait.h>
+#include <unistd.h>
+#include <sys/mman.h>
+#include <sys/types.h>
+
+#include <libreichwein/file.h>
+#include <libreichwein/process.h>
+
+using namespace std::string_literals;
+namespace fs = std::filesystem;
+namespace pt = boost::property_tree;
+using namespace Reichwein;
+
+#define FCGI_LISTENSOCK_FILENO 0
+
+FastCGIProcess::FastCGIProcess(const std::filesystem::path& exe_path, const std::string& host, unsigned short port):
+ m_pid{},
+ m_command{exe_path.generic_string()},
+ m_host{host},
+ m_port{port}
+{
+ start();
+}
+
+FastCGIProcess::FastCGIProcess(const std::filesystem::path& exe_path, const fs::path& socket_path):
+ m_pid{},
+ m_command{exe_path.generic_string()},
+ m_socket_path{socket_path}
+{
+ start();
+}
+
+FastCGIProcess::~FastCGIProcess()
+{
+ stop();
+}
+
+void FastCGIProcess::start()
+{
+ if (m_pid != 0)
+  throw std::runtime_error("Process already running, so it can't be started");
+
+ m_pid = fork();
+ if (m_pid < 0)
+  throw std::runtime_error("Fork unsuccessful.");
+
+ if (m_pid == 0) { // child process branch
+  try {
+   int fd{};
+   boost::asio::io_context ioc;
+   boost::asio::ip::tcp::resolver resolver(ioc);
+   boost::asio::ip::tcp::acceptor acceptor(ioc);
+   boost::asio::local::stream_protocol::acceptor file_acceptor(ioc);
+
+   if (m_socket_path.empty()) { // tcp connection
+    auto const results = resolver.resolve(m_host.c_str(), std::to_string(m_port).c_str());
+    if (results.begin() == results.end())
+     std::runtime_error("no resolve result");
+    boost::asio::ip::tcp::endpoint endpoint{*results.begin()};
+    acceptor.open(endpoint.protocol());
+    acceptor.set_option(boost::asio::ip::tcp::acceptor::reuse_address(true));
+    acceptor.bind(endpoint);
+    acceptor.listen();
+    fd = acceptor.native_handle();
+   } else { // unix domain socket
+    std::error_code ec;
+    fs::remove(m_socket_path, ec); // otherwise we get: "bind: Address already in use"
+
+    boost::asio::local::stream_protocol::endpoint endpoint(m_socket_path);
+    file_acceptor.open(endpoint.protocol());
+    file_acceptor.set_option(boost::asio::local::stream_protocol::acceptor::reuse_address(true));
+    file_acceptor.bind(endpoint);
+    file_acceptor.listen();
+    fd = file_acceptor.native_handle();
+   }
+
+   if (fd != FCGI_LISTENSOCK_FILENO) {
+    close(FCGI_LISTENSOCK_FILENO);
+    dup2(fd, FCGI_LISTENSOCK_FILENO);
+    close(fd);
+   }
+
+   execl(m_command.c_str(),  m_command.c_str(), (const char*)nullptr);
+  } catch (const std::exception& ex) {
+   std::cout << "FastCGI process error: " << ex.what() << std::endl;
+  }
+  exit(0);
+ }
+
+ // wait for server to start up
+ if (m_socket_path.empty()) { // tcp connection
+  Process::wait_for_pid_listening_on(m_pid, m_port);
+ } else { // unix domain socket
+  Process::wait_for_pid_listening_on(m_pid, m_socket_path);
+ }
+ std::this_thread::sleep_for(std::chrono::milliseconds(10));
+}
+
+void FastCGIProcess::stop()
+{
+ if (m_pid == 0)
+  throw std::runtime_error("Process not running, so it can't be stopped");
+ 
+ if (kill(m_pid, SIGTERM) != 0)
+  throw std::runtime_error("Unable to kill process");
+
+ if (int result = waitpid(m_pid, NULL, 0); result != m_pid)
+  throw std::runtime_error("waitpid returned "s + std::to_string(result));
+
+ if (!m_socket_path.empty()) {
+  std::error_code ec;
+  fs::remove(m_socket_path, ec);
+ }
+
+ m_pid = 0;
+}
+
+bool FastCGIProcess::is_running()
+{
+ if (m_pid == 0)
+  return false;
+
+ return Process::is_running(m_pid);
+}
+
-- 
cgit v1.2.3