Add daemonization support.

linux/server/Main.cxx

@@ -2,16 +2,32 @@
 #include <format>
 #include <iostream>
 
+#include <microsoft/net/remote/NetRemoteServerConfiguration.hxx>
 #include <microsoft/net/remote/NetRemoteServer.hxx>
+#include <unistd.h>
 
 using namespace Microsoft::Net::Remote;
 
 int
 main(int argc, char* argv[])
 {
-    NetRemoteServer server{ argc, argv };
+    const auto configuration = NetRemoteServerConfiguration::FromCommandLineArguments(argc, argv);
+
+    NetRemoteServer server{ configuration.ServerAddress };
     server.Run();
-    server.GetGrpcServer()->Wait();
+
+    if (configuration.RunInBackground)
+    {
+        constexpr int nochdir = 0; // Change current working directory to /
+        constexpr int noclose = 0; // Don't redirect stdin, stdout to /dev/null
+
+        if (daemon(nochdir, noclose) != 0) {
+            const int error = errno;
+            const auto what = std::format("failed to daemonize (error={})", error);
+            std::cerr << what << std::endl;
+            throw std::runtime_error(what);
+        }
+    }
 
     return 0;
 }

src/server/CMakeLists.txt

@@ -7,8 +7,10 @@ set(NET_REMOTE_SERVER_PUBLIC_INCLUDE_PREFIX ${NET_REMOTE_SERVER_PUBLIC_INCLUDE}/
 target_sources(netremote-server
     PRIVATE
         NetRemoteServer.cxx
+        NetRemoteServerConfiguration.cxx
     PUBLIC
         ${NET_REMOTE_SERVER_PUBLIC_INCLUDE_PREFIX}/NetRemoteServer.hxx
+        ${NET_REMOTE_SERVER_PUBLIC_INCLUDE_PREFIX}/NetRemoteServerConfiguration.hxx
 )
 
 target_include_directories(netremote-server
@@ -23,6 +25,15 @@ target_link_libraries(netremote-server
         CLI11::CLI11
 )
 
+list(APPEND NET_REMOTE_SERVER_PUBLIC_HEADERS
+    ${NET_REMOTE_SERVER_PUBLIC_INCLUDE_PREFIX}/NetRemoteServer.hxx
+    ${NET_REMOTE_SERVER_PUBLIC_INCLUDE_PREFIX}/NetRemoteServerConfiguration.hxx
+)
+
+set_target_properties(netremote-server PROPERTIES
+    PUBLIC_HEADER "${NET_REMOTE_SERVER_PUBLIC_HEADERS}"
+)
+
 install(
     TARGETS netremote-server
     EXPORT netremote

src/server/NetRemoteServer.cxx

@@ -8,33 +8,9 @@
 
 using namespace Microsoft::Net::Remote;
 
-NetRemoteServer::NetRemoteServer(int argc, char* argv[])
-{
-    try 
-    {
-        m_cliParser->parse(argc, argv);
-    }
-    catch (const CLI::ParseError& e)
-    {
-        const auto failureMessage = std::format("Failed to parse command-line arguments ({}).", e.what());
-        std::cerr << std::format("{}\n{}", failureMessage, m_cliParser->help()) << std::endl;
-        throw std::runtime_error{ failureMessage };
-    }
-
-    // At this point, all supported command line arguments have been parsed.
-    // However, there are no command-line arguments currently supported, so
-    // there is nothing to do here. This should be updated to tease out the
-    // command line arguments from m_cliParser and save them to member variables
-    // if/when some arguments are supported.
-}
-
-/* static */
-std::unique_ptr<CLI::App> NetRemoteServer::CreateCliParser()
-{
-    auto app = std::make_unique<CLI::App>("NetRemoteServer");
-    // TODO: configure CLI11 app with supported options. Currently none.
-    return app;
-}
+NetRemoteServer::NetRemoteServer(std::string_view serverAddress) :
+    m_serverAddress{ serverAddress }
+{}
 
 std::unique_ptr<grpc::Server>& NetRemoteServer::GetGrpcServer() noexcept
 {

src/server/NetRemoteServerConfiguration.cxx

@@ -0,0 +1,64 @@
+
+#include <utility>
+
+#include <CLI/CLI.hpp>
+#include <microsoft/net/remote/NetRemoteServerConfiguration.hxx>
+
+using namespace Microsoft::Net::Remote;
+
+namespace details
+{
+CLI::App&
+ConfigureCliAppOptions(CLI::App& app, NetRemoteServerConfiguration& config)
+{
+    app.add_flag(
+        "-d",
+        config.RunInBackground,
+        "Run the service as a daemon in the background");
+
+    app.add_option(
+        "-a,--address",
+        config.ServerAddress,
+        "The address to listen on for incoming connections.");
+
+    return app;
+}
+
+template <typename... Args>
+NetRemoteServerConfiguration
+ParseCliAppOptions(bool throwOnParseError, Args&&... args)
+{
+    CLI::App app{};
+    NetRemoteServerConfiguration configuration{};
+    ConfigureCliAppOptions(app, configuration);
+
+    try
+    {
+        app.parse(std::forward<Args>(args)...);
+    }
+    catch (const CLI::ParseError& parseError)
+    {
+        if (throwOnParseError)
+        {
+            throw parseError;
+        }
+    }
+
+    return configuration;
+}
+
+} // namespace details
+
+/* static */
+NetRemoteServerConfiguration
+NetRemoteServerConfiguration::FromCommandLineArguments(int argc, char* argv[], bool throwOnParseError)
+{
+    return details::ParseCliAppOptions(throwOnParseError, argc, argv);
+}
+
+/* static */
+NetRemoteServerConfiguration
+NetRemoteServerConfiguration::FromCommandLineArguments(std::vector<std::string>& args, bool throwOnParseError)
+{
+    return details::ParseCliAppOptions(throwOnParseError, args);
+}

src/server/include/microsoft/net/remote/NetRemoteServer.hxx

@@ -6,7 +6,6 @@
 #include <string_view>
 #include <string>
 
-#include <CLI/CLI.hpp>
 #include <grpcpp/server.h>
 #include <microsoft/net/remote/NetRemoteService.hxx>
 
@@ -18,17 +17,11 @@ namespace Microsoft::Net::Remote
 struct NetRemoteServer
 {
     /**
-     * @brief Default address for the server to listen on.
-     */
-    static constexpr auto ServerAddressDefault = "0.0.0.0:5047";
-
-    /**
-     * @brief Construct a new NetRemoteServer object from command-line arguments.
+     * @brief Construct a new NetRemoteServer object.
      * 
-     * @param argc The number of arguments.
-     * @param argv An array of 'argc' arguments.
+     * @param serverAddress 
      */
-    NetRemoteServer(int argc, char* argv[]);
+    NetRemoteServer(std::string_view serverAddress);
 
     /**
      * @brief Get the GrpcServer object.
@@ -48,18 +41,8 @@ struct NetRemoteServer
     void Stop();
 
 private:
-    /**
-     * @brief Create a CLI11 parser object configured with the supported CLI
-     * arguments.
-     * 
-     * @return std::unique_ptr<CLI::App> 
-     */
-    static std::unique_ptr<CLI::App> CreateCliParser();
-
-private:
-    std::string m_serverAddress{ ServerAddressDefault };
+    std::string m_serverAddress;
     std::unique_ptr<grpc::Server> m_server;
-    std::unique_ptr<CLI::App> m_cliParser;
     Service::NetRemoteService m_service{};
 };
 } // namespace Microsoft::Net::Remote

src/server/include/microsoft/net/remote/NetRemoteServerConfiguration.hxx

@@ -0,0 +1,53 @@
+
+#ifndef NET_REMOTE_SERVER_CONFIGURATION_HXX
+#define NET_REMOTE_SERVER_CONFIGURATION_HXX
+
+#include <string>
+#include <vector>
+
+namespace Microsoft::Net::Remote
+{
+struct NetRemoteServerConfiguration
+{
+    /**
+     * @brief Default address for the server to listen on.
+     */
+    static constexpr auto ServerAddressDefault = "0.0.0.0:5047";
+
+    /**
+     * @brief Create a NetRemoteServerConfiguration object from command-line
+     * arguments.
+     * 
+     * @param argc 
+     * @param argv 
+     * @param throwOnParseError
+     * @return NetRemoteServerConfiguration 
+     */
+    static NetRemoteServerConfiguration
+    FromCommandLineArguments(int argc, char* argv[], bool throwOnParseError = false);
+
+    /**
+     * @brief Create a NetRemoteServerConfiguration object from command-line
+     * arguments.
+     * 
+     * @param args 
+     * @param throwOnParseError
+     * @return NetRemoteServerConfiguration 
+     */
+    static NetRemoteServerConfiguration
+    FromCommandLineArguments(std::vector<std::string>& args, bool throwOnParseError = false);
+
+    /**
+     * @brief Default address for the server to listen on.
+     */
+    std::string ServerAddress{ ServerAddressDefault };
+
+    /**
+     * @brief Run the service in the background.
+     */
+    bool RunInBackground{ true };
+};
+
+} // namespace Microsoft::Net::Remote
+
+#endif // NET_REMOTE_SERVER_CONFIGURATION_HXX