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
  28 char *data_directory = "/usr/local/citadel";
  29 char *http_port = "80";
  30 char *https_port = "443";
  31
  32 pid_t start_citadel() {
  33         char bin[1024];
  34         sprintf(bin, "%s/usr/local/citadel/citserver", getenv("APPDIR"));
  35         pid_t pid = fork();
  36         if (pid == 0) {
  37                 fprintf(stderr, "ctdlvisor: executing %s\n", bin);
  38                 execlp(bin, "citserver", "-x9", "-h", data_directory, NULL);
  39                 perror("execlp");
  40                 exit(errno);
  41         }
  42         else {
  43                 return(pid);
  44         }
  45 }
  46
  47
  48 pid_t start_webcit() {
  49         char bin[1024];
  50         sprintf(bin, "%s/usr/local/webcit/webcit", getenv("APPDIR"));
  51         char wchome[1024];
  52         sprintf(wchome, "-h%s/usr/local/webcit", getenv("APPDIR"));
  53         pid_t pid = fork();
  54         if (pid == 0) {
  55                 fprintf(stderr, "ctdlvisor: executing %s\n", bin);
  56                 execlp(bin, "webcit", "-x9", wchome, "-p", http_port, "uds", data_directory, NULL);
  57                 perror("execlp");
  58                 exit(errno);
  59         }
  60         else {
  61                 return(pid);
  62         }
  63 }
  64
  65
  66 pid_t start_webcits() {
  67         char bin[1024];
  68         sprintf(bin, "%s/usr/local/webcit/webcit", getenv("APPDIR"));
  69         char wchome[1024];
  70         sprintf(wchome, "-h%s/usr/local/webcit", getenv("APPDIR"));
  71         pid_t pid = fork();
  72         if (pid == 0) {
  73                 fprintf(stderr, "ctdlvisor: executing %s\n", bin);
  74                 execlp(bin, "webcit", "-x9", wchome, "-s", "-p", https_port, "uds", data_directory, NULL);
  75                 perror("execlp");
  76                 exit(errno);
  77         }
  78         else {
  79                 return(pid);
  80         }
  81 }
  82
  83
  84 int main(int argc, char **argv) {
  85         pid_t citserver_pid;
  86         pid_t webcit_pid;
  87         pid_t webcits_pid;
  88         int shutting_down = 0;
  89         int status;
  90         pid_t who_exited;
  91         int c;
  92
  93         while ((c = getopt (argc, argv, "h:p:s:")) != -1)  switch(c) {
  94                 case 'h':
  95                         data_directory = optarg;
  96                         break;
  97                 case 'p':
  98                         http_port = optarg;
  99                         break;
 100                 case 's':
 101                         https_port = optarg;
 102                         break;
 103                 default:
 104                         fprintf(stderr, "ctdlvisor: usage: ctdlvisor [-h data_directory] [-p http_port] [-s https_port]\n");
 105                         exit(1);
 106         }
 107
 108         fprintf(stderr, "ctdlvisor: Welcome to the Citadel System, brought to you using AppImage.\n");
 109         fprintf(stderr, "ctdlvisor: LD_LIBRARY_PATH = %s\n", getenv("LD_LIBRARY_PATH"));
 110         fprintf(stderr, "ctdlvisor:            PATH = %s\n", getenv("PATH"));
 111         fprintf(stderr, "ctdlvisor:          APPDIR = %s\n", getenv("APPDIR"));
 112         fprintf(stderr, "ctdlvisor:  data directory = %s\n", data_directory);
 113         fprintf(stderr, "ctdlvisor:       HTTP port = %s\n", http_port);
 114         fprintf(stderr, "ctdlvisor:      HTTPS port = %s\n", https_port);
 115
 116         if (access(data_directory, R_OK|W_OK|X_OK)) {
 117                 fprintf(stderr, "ctdlvisor: %s: %s\n", data_directory, strerror(errno));
 118                 exit(errno);
 119         }
 120
 121         citserver_pid = start_citadel();
 122         webcit_pid = start_webcit();
 123         webcits_pid = start_webcits();
 124
 125         do {
 126                 fprintf(stderr, "ctdlvisor: waiting for any child process to exit...\n");
 127                 who_exited = waitpid(-1, &status, 0);
 128                 fprintf(stderr, "ctdlvisor: pid=%d exited, status=%d, exitcode=%d\n", who_exited, status, WEXITSTATUS(status));
 129
 130                 // A *deliberate* exit of citserver will cause ctdlvisor to shut the whole AppImage down.
 131                 // If it crashes, however, we will start it back up.
 132                 if (who_exited == citserver_pid) {
 133                         if (WEXITSTATUS(status) == 0) {
 134                                 fprintf(stderr, "ctdlvisor: citserver exited normally - ending AppImage session\n");
 135                                 shutting_down = 1;
 136                                 kill(webcit_pid, SIGTERM);
 137                                 kill(webcits_pid, SIGTERM);
 138                         }
 139                         else {
 140                                 citserver_pid = start_citadel();
 141                         }
 142                 }
 143
 144                 // WebCit processes are restarted if they exit for any reason.
 145                 if ((who_exited == webcit_pid) && (!shutting_down))             webcit_pid = start_webcit();
 146                 if ((who_exited == webcits_pid) && (!shutting_down))            webcits_pid = start_webcits();
 147
 148                 // If we somehow end up in an endless loop, at least slow it down.
 149                 sleep(1);
 150
 151         } while ((who_exited >= 0) && (shutting_down == 0));
 152
 153         printf("ctdlvisor: exiting.\n");
 154         exit(0);
 155 }