Various changes to appimage. Removed some old docs.
[citadel.git] / appimage / ctdlvisor.c
index 63230afaef3338132212cb9105dbc0f7fe6f6c38..405a56bdaed68426601981707e640e7a29613387 100644 (file)
 #include <stdio.h>
 #include <sys/wait.h>
 #include <errno.h>
+#include <signal.h>
+#include <string.h>
+#include <limits.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+
+pid_t citserver_pid;
+pid_t webcit_pid;
+pid_t webcits_pid;
+int shutting_down = 0;
+
+// Call this instead of exit() just for common diagnostics etc.
+void ctdlvisor_exit(int code) {
+       printf("ctdlvisor: exit code %d\n", code);
+       exit(code);
+}
+
+
+// Interrupting this program with a signal will begin an orderly shutdown.
+void signal_handler(int signal) {
+       fprintf(stderr, "ctdlvisor: caught signal %d\n", signal);
+
+       while(shutting_down) {
+               fprintf(stderr, "ctdlvisor: already shutting down\n");
+               sleep(1);
+       }
+
+       int status;
+       pid_t who_exited;
+       char *what_exited = NULL;
+
+       shutting_down = 1;
+       kill(citserver_pid, SIGTERM);
+       kill(webcit_pid, SIGTERM);
+       kill(webcits_pid, SIGTERM);
+       do {
+               fprintf(stderr, "ctdlvisor: waiting for all child process to exit...\n");
+               who_exited = waitpid(-1, &status, 0);
+               if (who_exited == citserver_pid) {
+                       what_exited = "Citadel Server";
+               }
+               else if (who_exited == webcit_pid) {
+                       what_exited = "WebCit HTTP";
+               }
+               else if (who_exited == webcits_pid) {
+                       what_exited = "WebCit HTTPS";
+               }
+               else {
+                       what_exited = "unknown";
+               }
+               if (who_exited >= 0) {
+                       if (WIFEXITED(status)) {
+                               fprintf(stderr, "ctdlvisor: %d (%s) exited, exitcode=%d\n", who_exited, what_exited, WEXITSTATUS(status));
+                       }
+                       else if (WIFSIGNALED(status)) {
+                               fprintf(stderr, "ctdlvisor: %d (%s) crashed, signal=%d\n", who_exited, what_exited, WTERMSIG(status));
+                       }
+                       else {
+                               fprintf(stderr, "ctdlvisor: %d (%s) ended, status=%d\n", who_exited, what_exited, status);
+                       }
+               }
+       } while (who_exited >= 0);
+       ctdlvisor_exit(0);
+}
+
+
+void detach_from_tty(void) {
+       signal(SIGHUP, SIG_IGN);
+       signal(SIGINT, SIG_IGN);
+       signal(SIGQUIT, SIG_IGN);
+
+       setsid();       // become our own process group leader
+       umask(0);
+       if (    (freopen("/dev/null", "r", stdin) != stdin) ||
+               (freopen("/dev/null", "w", stdout) != stdout) ||
+               (freopen("/dev/null", "w", stderr) != stderr)
+       ) {
+               fprintf(stderr, "sysdep: unable to reopen stdio: %s\n", strerror(errno));
+       }
+}
 
 
 pid_t start_citadel() {
@@ -28,12 +108,13 @@ pid_t start_citadel() {
        sprintf(bin, "%s/usr/local/citadel/citserver", getenv("APPDIR"));
        pid_t pid = fork();
        if (pid == 0) {
-               printf("Executing %s\n", bin);
-               execlp(bin, "citserver", "-x9", "-h/usr/local/citadel", NULL);
-               perror("execlp");
+               fprintf(stderr, "ctdlvisor: executing %s with data directory %s\n", bin, getenv("CTDL_DIR"));
+               detach_from_tty();
+               execlp(bin, "citserver", "-x9", "-h", getenv("CTDL_DIR"), NULL);
                exit(errno);
        }
        else {
+               fprintf(stderr, "ctdlvisor: citserver running on pid=%d\n", pid);
                return(pid);
        }
 }
@@ -42,14 +123,17 @@ pid_t start_citadel() {
 pid_t start_webcit() {
        char bin[1024];
        sprintf(bin, "%s/usr/local/webcit/webcit", getenv("APPDIR"));
+       char wchome[1024];
+       sprintf(wchome, "-h%s/usr/local/webcit", getenv("APPDIR"));
        pid_t pid = fork();
        if (pid == 0) {
-               printf("Executing %s\n", bin);
-               execlp(bin, "webcit", "-x9", "-p80", "uds", "/usr/local/citadel", NULL);
-               perror("execlp");
+               fprintf(stderr, "ctdlvisor: executing %s\n", bin);
+               detach_from_tty();
+               execlp(bin, "webcit", "-x9", wchome, "-p", getenv("HTTP_PORT"), "uds", getenv("CTDL_DIR"), NULL);
                exit(errno);
        }
        else {
+               fprintf(stderr, "ctdlvisor: webcit (HTTP) running on pid=%d\n", pid);
                return(pid);
        }
 }
@@ -58,51 +142,110 @@ pid_t start_webcit() {
 pid_t start_webcits() {
        char bin[1024];
        sprintf(bin, "%s/usr/local/webcit/webcit", getenv("APPDIR"));
+       char wchome[1024];
+       sprintf(wchome, "-h%s/usr/local/webcit", getenv("APPDIR"));
        pid_t pid = fork();
        if (pid == 0) {
-               printf("Executing %s\n", bin);
-               execlp(bin, "webcit", "-x9", "-s", "-p443", "uds", "/usr/local/citadel", NULL);
-               perror("execlp");
+               fprintf(stderr, "ctdlvisor: executing %s\n", bin);
+               detach_from_tty();
+               execlp(bin, "webcit", "-x9", wchome, "-s", "-p", getenv("HTTPS_PORT"), "uds", getenv("CTDL_DIR"), NULL);
                exit(errno);
        }
        else {
+               fprintf(stderr, "ctdlvisor: webcit (HTTPS) running on pid=%d\n", pid);
                return(pid);
        }
 }
 
 
-main() {
+void test_binary_compatibility(void) {
+       char cmd[1024];
+       int ret;
+       fprintf(stderr, "ctdlvisor: testing compatibility...\n");
+       sprintf(cmd, "%s/usr/local/citadel/citserver -c", getenv("APPDIR"));
+       ret = system(cmd);
+       if (ret) {
+               fprintf(stderr, "ctdlvisor: this appimage cannot run on your system.\n"
+                               "           The reason may be indicated by any error messages appearing above.\n");
+       }
+       else {
+               fprintf(stderr, "ctdlvisor: this appimage appears to be compatible with your system.\n");
+       }
+       exit(ret);
+}
+
+
+void main_loop(void) {
        int status;
        pid_t who_exited;
-
-       pid_t citserver_pid = start_citadel();
-       pid_t webcit_pid = start_webcit();
-       pid_t webcits_pid = start_webcits();
+       int citserver_exit_code = 0;
 
        do {
-               printf("LD_LIBRARY_PATH = %s\n", getenv("LD_LIBRARY_PATH"));
-               printf("PATH = %s\n", getenv("PATH"));
-               printf("APPDIR = %s\n", getenv("APPDIR"));
-
-               printf("waiting...\n");
                who_exited = waitpid(-1, &status, 0);
-               printf("pid=%d exited, status=%d\n", who_exited, status);
+               fprintf(stderr, "ctdlvisor: pid=%d exited, status=%d, exitcode=%d\n", who_exited, status, WEXITSTATUS(status));
 
+               // A *deliberate* exit of citserver will cause ctdlvisor to shut the whole AppImage down.
+               // If it crashes, however, we will start it back up.
                if (who_exited == citserver_pid) {
-                       if (WEXITSTATUS(status) == 0) {
-                               printf("ctdlvisor: citserver exited normally - ending AppImage session\n");
-                               exit(0);
+                       citserver_exit_code = WEXITSTATUS(status);
+                       if (citserver_exit_code == 0) {
+                               fprintf(stderr, "ctdlvisor: citserver exited normally - ending AppImage session\n");
+                               shutting_down = 1;
+                               kill(webcit_pid, SIGTERM);
+                               kill(webcits_pid, SIGTERM);
+                       }
+                       else if ((citserver_exit_code >= 101) && (citserver_exit_code <= 109)) {
+                               fprintf(stderr, "ctdlvisor: citserver exited intentionally - ending AppImage session\n");
+                               shutting_down = 1;
+                               kill(webcit_pid, SIGTERM);
+                               kill(webcits_pid, SIGTERM);
+                       }
+                       else {
+                               citserver_pid = start_citadel();
                        }
-                       citserver_pid = start_citadel();
                }
 
-               if (who_exited == webcit_pid)           webcit_pid = start_webcit();
-               if (who_exited == webcits_pid)          webcits_pid = start_webcits();
+               // WebCit processes are restarted if they exit for any reason.
+               if ((who_exited == webcit_pid) && (!shutting_down))     webcit_pid = start_webcit();
+               if ((who_exited == webcits_pid) && (!shutting_down))    webcits_pid = start_webcits();
 
-               sleep(1);                               // slow down any accidental loops
+               // If we somehow end up in an endless loop, at least slow it down.
+               sleep(1);
 
        } while (who_exited >= 0);
+       ctdlvisor_exit(citserver_exit_code);
+}
+
+
+int main(int argc, char **argv) {
+
+       if (getenv("APPDIR") == NULL) {
+               fprintf(stderr, "ctdlvisor: APPDIR is not set.  This program must be run from within an AppImage.\n");
+               ctdlvisor_exit(1);
+       }
+
+       fprintf(stderr, "ctdlvisor: Welcome to the Citadel System, brought to you using AppImage.\n");
+       fprintf(stderr, "ctdlvisor: LD_LIBRARY_PATH = %s\n", getenv("LD_LIBRARY_PATH"));
+       fprintf(stderr, "ctdlvisor:            PATH = %s\n", getenv("PATH"));
+       fprintf(stderr, "ctdlvisor:          APPDIR = %s\n", getenv("APPDIR"));
+       fprintf(stderr, "ctdlvisor:  data directory = %s\n", getenv("CTDL_DIR"));
+       fprintf(stderr, "ctdlvisor:       HTTP port = %s\n", getenv("HTTP_PORT"));
+       fprintf(stderr, "ctdlvisor:      HTTPS port = %s\n", getenv("HTTPS_PORT"));
+
+       if (access(getenv("CTDL_DIR"), R_OK|W_OK|X_OK)) {
+               fprintf(stderr, "ctdlvisor: %s: %s\n", getenv("CTDL_DIR"), strerror(errno));
+               ctdlvisor_exit(errno);
+       }
+
+       signal(SIGTERM, signal_handler);
+       signal(SIGHUP, signal_handler);
+       signal(SIGINT, signal_handler);
+       signal(SIGQUIT, signal_handler);
+
+       citserver_pid = start_citadel();
+       webcit_pid = start_webcit();
+       webcits_pid = start_webcits();
 
-       printf("ctdlvisor: exiting.\n");
-       exit(0);
+       main_loop();
+       ctdlvisor_exit(0);
 }