Files
uwsgi/core/daemons.c
T

405 lines
9.2 KiB
C

#include <uwsgi.h>
extern struct uwsgi_server uwsgi;
/*
External uwsgi daemons
There are 3 kind of daemons (read: external applications) that can be managed
by uWSGI.
1) dumb daemons (attached with --attach-daemon)
they must not daemonize() and when they exit() the master is notified (via waitpid)
and the process is respawned
2) smart daemons with daemonization
you specify a pidfile and a command
- on startup - if the pidfile does not exists or contains a not-available pid (checked with kill(pid, 0))
the daemon is respawned
- on master ckeck - if the pidfile does not exist or if it point to a non-existent pid
the daemon is respawned
3) smart daemons without daemonization
same as 2, but the daemonization and pidfile creation is managed by uWSGI
status:
0 -> never started
1 -> just started
2 -> started and monitored (only in pidfile based)
*/
void uwsgi_daemons_smart_check() {
static time_t last_run = 0;
time_t now = uwsgi_now();
if (now - last_run <= 0) {
return;
}
last_run = now;
struct uwsgi_daemon *ud = uwsgi.daemons;
while (ud) {
#ifdef UWSGI_SSL
if (ud->legion) {
if (uwsgi_legion_i_am_the_lord(ud->legion)) {
// lord, spawn if not running
if (ud->pid <= 0) {
uwsgi_spawn_daemon(ud);
}
}
else {
// not lord, kill daemon if running
if (ud->pid > 0) {
if (!kill(ud->pid, 0)) {
uwsgi_log("[uwsgi_daemons] stopping legion \"%s\" daemon: %s (pid: %d)\n", ud->legion, ud->command, ud->pid);
kill(-ud->pid, SIGTERM);
}
else {
// pid already died
ud->pid = -1;
}
}
ud = ud->next;
continue;
}
}
#endif
if (ud->pidfile) {
int checked_pid = uwsgi_check_pidfile(ud->pidfile);
if (checked_pid <= 0) {
// monitored instance
if (ud->status == 2) {
uwsgi_spawn_daemon(ud);
}
else {
ud->pidfile_checks++;
if (ud->pidfile_checks >= (unsigned int) ud->freq) {
uwsgi_log("[uwsgi-daemons] found changed pidfile for \"%s\" (old_pid: %d new_pid: %d)\n", ud->command, (int) ud->pid, (int) checked_pid);
uwsgi_spawn_daemon(ud);
}
}
}
else if (checked_pid != ud->pid) {
uwsgi_log("[uwsgi-daemons] found changed pid for \"%s\" (old_pid: %d new_pid: %d)\n", ud->command, (int) ud->pid, (int) checked_pid);
ud->pid = checked_pid;
}
// all ok, pidfile and process found
else {
ud->status = 2;
}
}
ud = ud->next;
}
}
// this function is called when a dumb daemon dies and we do not want to respawn it
int uwsgi_daemon_check_pid_death(pid_t diedpid) {
struct uwsgi_daemon *ud = uwsgi.daemons;
while (ud) {
if (ud->pid == diedpid && !ud->pidfile) {
uwsgi_log("daemon \"%s\" (pid: %d) annihilated\n", ud->command, (int) diedpid);
ud->pid = -1;
return -1;
}
ud = ud->next;
}
return 0;
}
// this function is called when a dumb daemon dies and we want to respawn it
int uwsgi_daemon_check_pid_reload(pid_t diedpid) {
struct uwsgi_daemon *ud = uwsgi.daemons;
while (ud) {
#ifdef UWSGI_SSL
if (ud->pid == diedpid && ud->legion && !uwsgi_legion_i_am_the_lord(ud->legion)) {
// part of legion but not lord, don't respawn
ud->pid = -1;
uwsgi_log("uwsgi-daemons] legion \"%s\" daemon \"%s\" (pid: %d) annihilated\n", ud->legion, ud->command, (int) diedpid);
ud = ud->next;
continue;
}
#endif
if (ud->pid == diedpid && !ud->pidfile) {
uwsgi_spawn_daemon(ud);
return 1;
}
ud = ud->next;
}
return 0;
}
int uwsgi_check_pidfile(char *filename) {
struct stat st;
pid_t ret = -1;
int fd = open(filename, O_RDONLY);
if (fd < 0) {
uwsgi_error_open(filename);
goto end;
}
if (fstat(fd, &st)) {
uwsgi_error("fstat()");
goto end2;
}
char *pidstr = uwsgi_calloc(st.st_size + 1);
if (read(fd, pidstr, st.st_size) != st.st_size) {
uwsgi_error("read()");
goto end3;
}
pid_t pid = atoi(pidstr);
if (pid <= 0)
goto end3;
if (!kill(pid, 0)) {
ret = pid;
}
end3:
free(pidstr);
end2:
close(fd);
end:
return ret;
}
void uwsgi_daemons_spawn_all() {
struct uwsgi_daemon *ud = uwsgi.daemons;
while (ud) {
if (!ud->registered) {
#ifdef UWSGI_SSL
if (ud->legion && !uwsgi_legion_i_am_the_lord(ud->legion)) {
// part of legion, register but don't spawn it yet
if (ud->pidfile) {
ud->pid = uwsgi_check_pidfile(ud->pidfile);
if (ud->pid > 0)
uwsgi_log("[uwsgi-daemons] found valid/active pidfile for \"%s\" (pid: %d)\n", ud->command, (int) ud->pid);
}
ud->registered = 1;
ud = ud->next;
continue;
}
#endif
ud->registered = 1;
if (ud->pidfile) {
int checked_pid = uwsgi_check_pidfile(ud->pidfile);
if (checked_pid <= 0) {
uwsgi_spawn_daemon(ud);
}
else {
ud->pid = checked_pid;
uwsgi_log("[uwsgi-daemons] found valid/active pidfile for \"%s\" (pid: %d)\n", ud->command, (int) ud->pid);
}
}
else {
uwsgi_spawn_daemon(ud);
}
}
ud = ud->next;
}
}
void uwsgi_detach_daemons() {
struct uwsgi_daemon *ud = uwsgi.daemons;
while (ud) {
#ifdef UWSGI_SSL
// stop any legion daemon, doesn't matter if dumb or smart
if (ud->pid > 0 && (ud->legion || !ud->pidfile)) {
#else
// stop only dumb daemons
if (ud->pid > 0 && !ud->pidfile) {
#endif
uwsgi_log("[uwsgi-daemons] stopping daemon (pid: %d): %s\n", (int) ud->pid, ud->command);
// try to gracefully stop daemon, kill it if it won't die
// if mercy is not set than wait up to 3 seconds
time_t timeout = uwsgi_now() + (uwsgi.reload_mercy ? uwsgi.reload_mercy : 3);
while (!kill(ud->pid, 0)) {
kill(-ud->pid, SIGTERM);
sleep(1);
if (uwsgi_now() >= timeout) {
uwsgi_log("[uwsgi-daemons] daemon did not died in time, killing (pid: %d): %s\n", (int) ud->pid, ud->command);
kill(-ud->pid, SIGKILL);
break;
}
}
// unregister daemon to prevent it from being respawned
ud->registered = 0;
}
ud = ud->next;
}
}
void uwsgi_spawn_daemon(struct uwsgi_daemon *ud) {
// skip unregistered daemons
if (!ud->registered) return;
int devnull = -1;
int throttle = 0;
if (uwsgi.current_time - ud->last_spawn <= 3) {
throttle = ud->respawns - (uwsgi.current_time - ud->last_spawn);
}
pid_t pid = uwsgi_fork("uWSGI external daemon");
if (pid < 0) {
uwsgi_error("fork()");
return;
}
if (pid > 0) {
ud->pid = pid;
ud->status = 1;
ud->pidfile_checks = 0;
if (ud->respawns == 0) {
ud->born = uwsgi_now();
}
ud->respawns++;
ud->last_spawn = uwsgi_now();
}
else {
// close uwsgi sockets
uwsgi_close_all_sockets();
uwsgi_close_all_fds();
if (ud->daemonize) {
/* refork... */
pid = fork();
if (pid < 0) {
uwsgi_error("fork()");
exit(1);
}
if (pid != 0) {
_exit(0);
}
uwsgi_write_pidfile(ud->pidfile);
}
if (!uwsgi.daemons_honour_stdin) {
// /dev/null will became stdin
devnull = open("/dev/null", O_RDONLY);
if (devnull < 0) {
uwsgi_error("/dev/null open()");
exit(1);
}
if (devnull != 0) {
if (dup2(devnull, 0) < 0) {
uwsgi_error("dup2()");
exit(1);
}
close(devnull);
}
}
if (setsid() < 0) {
uwsgi_error("setsid()");
exit(1);
}
if (!ud->pidfile) {
#ifdef __linux__
if (prctl(PR_SET_PDEATHSIG, SIGKILL, 0, 0, 0)) {
uwsgi_error("prctl()");
}
#endif
}
if (throttle) {
uwsgi_log("[uwsgi-daemons] throttling \"%s\" for %d seconds\n", ud->command, throttle);
sleep(throttle);
}
uwsgi_log("[uwsgi-daemons] %sspawning \"%s\"\n", ud->respawns > 0 ? "re" : "", ud->command);
uwsgi_exec_command_with_args(ud->command);
uwsgi_log("[uwsgi-daemons] unable to spawn \"%s\"\n", ud->command);
// never here;
exit(1);
}
return;
}
void uwsgi_opt_add_daemon(char *opt, char *value, void *none) {
struct uwsgi_daemon *uwsgi_ud = uwsgi.daemons, *old_ud;
char *pidfile = NULL;
int daemonize = 0;
int freq = 10;
char *space = NULL;
char *command = uwsgi_str(value);
#ifdef UWSGI_SSL
char *legion = NULL;
if (!uwsgi_starts_with(opt, strlen(command), "legion-", 7)) {
space = strchr(command, ' ');
if (!space) {
uwsgi_log("invalid legion daemon syntax: %s\n", command);
exit(1);
}
*space = 0;
legion = command;
command = space+1;
}
#endif
if (!strcmp(opt, "smart-attach-daemon") || !strcmp(opt, "smart-attach-daemon2") || !strcmp(opt, "legion-smart-attach-daemon") || !strcmp(opt, "legion-smart-attach-daemon2")) {
space = strchr(command, ' ');
if (!space) {
uwsgi_log("invalid smart-attach-daemon syntax: %s\n", command);
exit(1);
}
*space = 0;
pidfile = command;
// check for freq
char *comma = strchr(pidfile, ',');
if (comma) {
*comma = 0;
freq = atoi(comma + 1);
}
command = space + 1;
if (!strcmp(opt, "smart-attach-daemon2") || !strcmp(opt, "legion-smart-attach-daemon2")) {
daemonize = 1;
}
}
if (!uwsgi_ud) {
uwsgi.daemons = uwsgi_malloc(sizeof(struct uwsgi_daemon));
uwsgi_ud = uwsgi.daemons;
}
else {
while (uwsgi_ud) {
old_ud = uwsgi_ud;
uwsgi_ud = uwsgi_ud->next;
}
uwsgi_ud = uwsgi_malloc(sizeof(struct uwsgi_daemon));
old_ud->next = uwsgi_ud;
}
uwsgi_ud->command = command;
uwsgi_ud->pid = 0;
uwsgi_ud->status = 0;
uwsgi_ud->freq = freq;
uwsgi_ud->registered = 0;
uwsgi_ud->next = NULL;
uwsgi_ud->respawns = 0;
uwsgi_ud->last_spawn = 0;
uwsgi_ud->daemonize = daemonize;
uwsgi_ud->pidfile = pidfile;
#ifdef UWSGI_SSL
uwsgi_ud->legion = legion;
#endif
uwsgi.daemons_cnt++;
}