appimage/ctdlvisor.c

   1 //
   2 // This is a supervisor program that handles start/stop/restart of
   3 // the various Citadel System components, when we are running on
   4 // an AppImage instance.
   5 //
   6 // Copyright (c) 2021 by the citadel.org team
   7 //
   8 // This program is open source software.  It runs great on the
   9 // Linux operating system (and probably elsewhere).  You can use,
  10 // copy, and run it under the terms of the GNU General Public
  11 // License version 3.  Richard Stallman is an asshole communist.
  12 //
  13 // This program is distributed in the hope that it will be useful,
  14 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  15 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16 // GNU General Public License for more details.
  17
  18
  19 #include <stdlib.h>
  20 #include <unistd.h>
  21 #include <stdio.h>
  22 #include <sys/wait.h>
  23 #include <errno.h>
  24 #include <signal.h>
  25 #include <string.h>
  26 #include <limits.h>
  27 #include <sys/types.h>
  28 #include <sys/stat.h>
  29
  30 void main_loop(void);
  31 void run_in_foreground(void);
  32
  33 char *data_directory = "/usr/local/citadel";
  34 char *http_port = "80";
  35 char *https_port = "443";
  36 pid_t citserver_pid;
  37 pid_t webcit_pid;
  38 pid_t webcits_pid;
  39 int shutting_down = 0;
  40
  41
  42 void ctdlvisor_exit(int code) {
  43         printf("ctdlvisor: exit code %d\n", code);
  44         exit(code);
  45 }
  46
  47
  48 void signal_handler(int signal) {
  49         fprintf(stderr, "ctdlvisor: caught signal %d\n", signal);
  50
  51         while(shutting_down) {
  52                 fprintf(stderr, "ctdlvisor: already shutting down\n");
  53                 sleep(1);
  54         }
  55
  56         int status;
  57         pid_t who_exited;
  58         char *what_exited = NULL;
  59
  60         shutting_down = 1;
  61         kill(citserver_pid, SIGTERM);
  62         kill(webcit_pid, SIGTERM);
  63         kill(webcits_pid, SIGTERM);
  64         do {
  65                 fprintf(stderr, "ctdlvisor: waiting for all child process to exit...\n");
  66                 who_exited = waitpid(-1, &status, 0);
  67                 if (who_exited == citserver_pid) {
  68                         what_exited = "Citadel Server";
  69                 }
  70                 else if (who_exited == webcit_pid) {
  71                         what_exited = "WebCit HTTP";
  72                 }
  73                 else if (who_exited == webcits_pid) {
  74                         what_exited = "WebCit HTTPS";
  75                 }
  76                 else {
  77                         what_exited = "unknown";
  78                 }
  79                 fprintf(stderr, "ctdlvisor: pid=%d (%s) exited, status=%d, exitcode=%d\n", who_exited, what_exited, status, WEXITSTATUS(status));
  80         } while (who_exited >= 0);
  81
  82         ctdlvisor_exit(0);
  83 }
  84
  85
  86
  87 void detach_from_tty(void) {
  88         signal(SIGHUP, SIG_IGN);
  89         signal(SIGINT, SIG_IGN);
  90         signal(SIGQUIT, SIG_IGN);
  91
  92         setsid();
  93         umask(0);
  94         if (    (freopen("/dev/null", "r", stdin) != stdin) ||
  95                 (freopen("/dev/null", "w", stdout) != stdout) ||
  96                 (freopen("/dev/null", "w", stderr) != stderr)
  97         ) {
  98                 fprintf(stderr, "sysdep: unable to reopen stdio: %s\n", strerror(errno));
  99         }
 100 }
 101
 102
 103 pid_t start_citadel() {
 104         char bin[1024];
 105         sprintf(bin, "%s/usr/local/citadel/citserver", getenv("APPDIR"));
 106         pid_t pid = fork();
 107         if (pid == 0) {
 108                 fprintf(stderr, "ctdlvisor: executing %s\n", bin);
 109                 detach_from_tty();
 110                 execlp(bin, "citserver", "-x9", "-h", data_directory, NULL);
 111                 exit(errno);
 112         }
 113         else {
 114                 return(pid);
 115         }
 116 }
 117
 118
 119 pid_t start_webcit() {
 120         char bin[1024];
 121         sprintf(bin, "%s/usr/local/webcit/webcit", getenv("APPDIR"));
 122         char wchome[1024];
 123         sprintf(wchome, "-h%s/usr/local/webcit", getenv("APPDIR"));
 124         pid_t pid = fork();
 125         if (pid == 0) {
 126                 fprintf(stderr, "ctdlvisor: executing %s\n", bin);
 127                 detach_from_tty();
 128                 execlp(bin, "webcit", "-x9", wchome, "-p", http_port, "uds", data_directory, NULL);
 129                 exit(errno);
 130         }
 131         else {
 132                 return(pid);
 133         }
 134 }
 135
 136
 137 pid_t start_webcits() {
 138         char bin[1024];
 139         sprintf(bin, "%s/usr/local/webcit/webcit", getenv("APPDIR"));
 140         char wchome[1024];
 141         sprintf(wchome, "-h%s/usr/local/webcit", getenv("APPDIR"));
 142         pid_t pid = fork();
 143         if (pid == 0) {
 144                 fprintf(stderr, "ctdlvisor: executing %s\n", bin);
 145                 detach_from_tty();
 146                 execlp(bin, "webcit", "-x9", wchome, "-s", "-p", https_port, "uds", data_directory, NULL);
 147                 exit(errno);
 148         }
 149         else {
 150                 return(pid);
 151         }
 152 }
 153
 154
 155 static char *usage =
 156         "ctdlvisor: usage: ctdlvisor [-h data_directory] [-p http_port] [-s https_port] command\n"
 157         "           'command' must be one of:\n"
 158         "           run     - start Citadel services in the foreground without detaching\n"
 159         "           install - deploy systemd unit files for automatic startup at boot\n"
 160         "           upgrade - check for new version of the software\n"
 161         "           test    - check this appimage for compatibility with your system\n"
 162 ;
 163
 164 int main(int argc, char **argv) {
 165         int c;
 166
 167         while ((c = getopt (argc, argv, "h:p:s:")) != -1)  switch(c) {
 168                 case 'h':
 169                         data_directory = optarg;
 170                         break;
 171                 case 'p':
 172                         http_port = optarg;
 173                         break;
 174                 case 's':
 175                         https_port = optarg;
 176                         break;
 177                 default:
 178                         fprintf(stderr, "%s", usage);
 179                         exit(1);
 180         }
 181
 182
 183         if (argc != optind+1) {
 184                 fprintf(stderr, "%s", usage);
 185                 exit(1);
 186         }
 187
 188         if (!strcasecmp(argv[optind], "run")) {
 189                 run_in_foreground();
 190         }
 191         else if (!strcasecmp(argv[optind], "install")) {
 192                 fprintf(stderr, "oops, this is not implemented yet\n");
 193         }
 194         else if (!strcasecmp(argv[optind], "upgrade")) {
 195                 fprintf(stderr, "oops, this is not implemented yet\n");
 196         }
 197         else if (!strcasecmp(argv[optind], "test")) {
 198                 fprintf(stderr, "oops, this is not implemented yet\n");
 199         }
 200         else {
 201                 fprintf(stderr, "%s", usage);
 202                 exit(1);
 203         }
 204
 205         exit(0);
 206 }
 207
 208
 209 void run_in_foreground(void) {
 210         fprintf(stderr, "ctdlvisor: Welcome to the Citadel System, brought to you using AppImage.\n");
 211         fprintf(stderr, "ctdlvisor: LD_LIBRARY_PATH = %s\n", getenv("LD_LIBRARY_PATH"));
 212         fprintf(stderr, "ctdlvisor:            PATH = %s\n", getenv("PATH"));
 213         fprintf(stderr, "ctdlvisor:          APPDIR = %s\n", getenv("APPDIR"));
 214         fprintf(stderr, "ctdlvisor:  data directory = %s\n", data_directory);
 215         fprintf(stderr, "ctdlvisor:       HTTP port = %s\n", http_port);
 216         fprintf(stderr, "ctdlvisor:      HTTPS port = %s\n", https_port);
 217
 218         if (access(data_directory, R_OK|W_OK|X_OK)) {
 219                 fprintf(stderr, "ctdlvisor: %s: %s\n", data_directory, strerror(errno));
 220                 exit(errno);
 221         }
 222
 223         signal(SIGTERM, signal_handler);
 224         signal(SIGHUP, signal_handler);
 225         signal(SIGINT, signal_handler);
 226         signal(SIGQUIT, signal_handler);
 227
 228         citserver_pid = start_citadel();
 229         webcit_pid = start_webcit();
 230         webcits_pid = start_webcits();
 231
 232         main_loop();
 233         exit(0);
 234 }
 235
 236
 237 void main_loop(void) {
 238         int status;
 239         pid_t who_exited;
 240         int citserver_exit_code = 0;
 241
 242         do {
 243                 fprintf(stderr, "ctdlvisor: waiting for any child process to exit...\n");
 244                 who_exited = waitpid(-1, &status, 0);
 245                 fprintf(stderr, "ctdlvisor: pid=%d exited, status=%d, exitcode=%d\n", who_exited, status, WEXITSTATUS(status));
 246
 247                 // A *deliberate* exit of citserver will cause ctdlvisor to shut the whole AppImage down.
 248                 // If it crashes, however, we will start it back up.
 249                 if (who_exited == citserver_pid) {
 250                         citserver_exit_code = WEXITSTATUS(status);
 251                         if (citserver_exit_code == 0) {
 252                                 fprintf(stderr, "ctdlvisor: citserver exited normally - ending AppImage session\n");
 253                                 shutting_down = 1;
 254                                 kill(webcit_pid, SIGTERM);
 255                                 kill(webcits_pid, SIGTERM);
 256                         }
 257                         else if ((citserver_exit_code >= 101) && (citserver_exit_code <= 109)) {
 258                                 fprintf(stderr, "ctdlvisor: citserver exited intentionally - ending AppImage session\n");
 259                                 shutting_down = 1;
 260                                 kill(webcit_pid, SIGTERM);
 261                                 kill(webcits_pid, SIGTERM);
 262                         }
 263                         else {
 264                                 citserver_pid = start_citadel();
 265                         }
 266                 }
 267
 268                 // WebCit processes are restarted if they exit for any reason.
 269                 if ((who_exited == webcit_pid) && (!shutting_down))     webcit_pid = start_webcit();
 270                 if ((who_exited == webcits_pid) && (!shutting_down))    webcits_pid = start_webcits();
 271
 272                 // If we somehow end up in an endless loop, at least slow it down.
 273                 sleep(1);
 274
 275         } while (who_exited >= 0);
 276
 277         ctdlvisor_exit(citserver_exit_code);
 278 }