Remove daemonize code (#5181)

Signed-off-by: shengjun.li <shengjun.li@zilliz.com>

core/src/main.cpp

@@ -29,8 +29,6 @@ print_help(const std::string& app_name) {
     std::cout << "  Options:" << std::endl;
     std::cout << "   -h --help                 Print this help." << std::endl;
     std::cout << "   -c --conf_file filename   Read configuration from the file." << std::endl;
-    std::cout << "   -d --daemon               Daemonize this application." << std::endl;
-    std::cout << "   -p --pid_file  filename   PID file used by daemonized app." << std::endl;
     std::cout << std::endl;
 }
 
@@ -102,16 +100,6 @@ main(int argc, char* argv[]) {
                 std::cout << "Loading configuration from: " << config_filename << std::endl;
                 break;
             }
-            case 'p': {
-                char* pid_filename_ptr = strdup(optarg);
-                pid_filename = pid_filename_ptr;
-                free(pid_filename_ptr);
-                std::cout << pid_filename << std::endl;
-                break;
-            }
-            case 'd':
-                start_daemonized = 1;
-                break;
             case 'h':
                 print_help(app_name);
                 return EXIT_SUCCESS;
@@ -132,7 +120,7 @@ main(int argc, char* argv[]) {
     signal(SIGUSR2, milvus::server::SignalUtil::HandleSignal);
     signal(SIGTERM, milvus::server::SignalUtil::HandleSignal);
 
-    server.Init(start_daemonized, pid_filename, config_filename);
+    server.Init(config_filename);
 
     s = server.Start();
     if (s.ok()) {

core/src/server/Server.cpp

@@ -52,102 +52,12 @@ Server::GetInstance() {
 }
 
 void
-Server::Init(int64_t daemonized, const std::string& pid_filename, const std::string& config_filename) {
-    daemonized_ = daemonized;
-    pid_filename_ = pid_filename;
+Server::Init(const std::string& config_filename) {
     config_filename_ = config_filename;
 }
 
-void
-Server::Daemonize() {
-    if (daemonized_ == 0) {
-        return;
-    }
-
-    std::cout << "Milvus server run in daemonize mode";
-
-    pid_t pid = 0;
-
-    // Fork off the parent process
-    pid = fork();
-
-    // An error occurred
-    if (pid < 0) {
-        exit(EXIT_FAILURE);
-    }
-
-    // Success: terminate parent
-    if (pid > 0) {
-        exit(EXIT_SUCCESS);
-    }
-
-    // On success: The child process becomes session leader
-    if (setsid() < 0) {
-        exit(EXIT_FAILURE);
-    }
-
-    // Ignore signal sent from child to parent process
-    signal(SIGCHLD, SIG_IGN);
-
-    // Fork off for the second time
-    pid = fork();
-
-    // An error occurred
-    if (pid < 0) {
-        exit(EXIT_FAILURE);
-    }
-
-    // Terminate the parent
-    if (pid > 0) {
-        exit(EXIT_SUCCESS);
-    }
-
-    // Set new file permissions
-    umask(0);
-
-    // Change the working directory to root
-    int ret = chdir("/");
-    if (ret != 0) {
-        return;
-    }
-
-    // Close all open fd
-    for (int64_t fd = sysconf(_SC_OPEN_MAX); fd > 0; fd--) {
-        close(fd);
-    }
-
-    std::cout << "Redirect stdin/stdout/stderr to /dev/null";
-
-    // Redirect stdin/stdout/stderr to /dev/null
-    stdin = fopen("/dev/null", "r");
-    stdout = fopen("/dev/null", "w+");
-    stderr = fopen("/dev/null", "w+");
-    // Try to write PID of daemon to lockfile
-    if (!pid_filename_.empty()) {
-        pid_fd_ = open(pid_filename_.c_str(), O_RDWR | O_CREAT, 0640);
-        if (pid_fd_ < 0) {
-            std::cerr << "Can't open filename: " + pid_filename_ + ", Error: " + strerror(errno);
-            exit(EXIT_FAILURE);
-        }
-        if (lockf(pid_fd_, F_TLOCK, 0) < 0) {
-            std::cerr << "Can't lock filename: " + pid_filename_ + ", Error: " + strerror(errno);
-            exit(EXIT_FAILURE);
-        }
-
-        std::string pid_file_context = std::to_string(getpid());
-        ssize_t res = write(pid_fd_, pid_file_context.c_str(), pid_file_context.size());
-        if (res != 0) {
-            return;
-        }
-    }
-}
-
 Status
 Server::Start() {
-    if (daemonized_ != 0) {
-        Daemonize();
-    }
-
     try {
         /* Read config file */
         Status s = LoadConfig();
@@ -327,29 +237,6 @@ Server::Stop() {
     }
 #endif
 
-    /* Unlock and close lockfile */
-    if (pid_fd_ != -1) {
-        int ret = lockf(pid_fd_, F_ULOCK, 0);
-        if (ret != 0) {
-            std::cerr << "ERROR: Can't lock file: " << strerror(errno) << std::endl;
-            exit(0);
-        }
-        ret = close(pid_fd_);
-        if (ret != 0) {
-            std::cerr << "ERROR: Can't close file: " << strerror(errno) << std::endl;
-            exit(0);
-        }
-    }
-
-    /* delete lockfile */
-    if (!pid_filename_.empty()) {
-        int ret = unlink(pid_filename_.c_str());
-        if (ret != 0) {
-            std::cerr << "ERROR: Can't unlink file: " << strerror(errno) << std::endl;
-            exit(0);
-        }
-    }
-
     StopService();
 
     std::cerr << "Milvus server exit..." << std::endl;

core/src/server/Server.h

@@ -23,7 +23,7 @@ class Server {
     GetInstance();
 
     void
-    Init(int64_t daemonized, const std::string& pid_filename, const std::string& config_filename);
+    Init(const std::string& config_filename);
 
     Status
     Start();
@@ -34,9 +34,6 @@ class Server {
     Server() = default;
     ~Server() = default;
 
-    void
-    Daemonize();
-
     Status
     LoadConfig();
 
@@ -46,9 +43,6 @@ class Server {
     StopService();
 
  private:
-    int64_t daemonized_ = 0;
-    int pid_fd_ = -1;
-    std::string pid_filename_;
     std::string config_filename_;
 };  // Server