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authorGlenn Strauss <gstrauss@gluelogic.com>2017-07-17 00:52:14 -0400
committerGlenn Strauss <gstrauss@gluelogic.com>2017-07-23 19:02:31 -0400
commitadeec956c39cdf57cd97027a7b3c734294b4f0a3 (patch)
tree6a26faa28c29b61e48f351f326c1922228efa254
parent167cdc846c13f03c87fe6f100c110282aa3cd17a (diff)
downloadlighttpd1.4-adeec956c39cdf57cd97027a7b3c734294b4f0a3.tar.gz
lighttpd1.4-adeec956c39cdf57cd97027a7b3c734294b4f0a3.zip
[core] restart piped loggers if they exit (fixes #1393)
x-ref: "access log pipe writer should restart child process if it exits" https://redmine.lighttpd.net/issues/1393
-rw-r--r--src/fdevent.c146
-rw-r--r--src/fdevent.h4
-rw-r--r--src/mod_accesslog.c6
-rw-r--r--src/server.c19
4 files changed, 157 insertions, 18 deletions
diff --git a/src/fdevent.c b/src/fdevent.c
index b73a08b3..28b07234 100644
--- a/src/fdevent.c
+++ b/src/fdevent.c
@@ -6,6 +6,7 @@
#include "log.h"
#include <sys/types.h>
+#include <sys/wait.h>
#include "sys-socket.h"
#include <unistd.h>
@@ -13,6 +14,7 @@
#include <string.h>
#include <errno.h>
#include <fcntl.h>
+#include <time.h>
#ifdef SOCK_CLOEXEC
static int use_sock_cloexec;
@@ -538,10 +540,24 @@ pid_t fdevent_fork_execve(const char *name, char *argv[], char *envp[], int fdin
}
-static int fdevent_open_logger_pipe(const char *logger) {
- /* create write pipe and spawn process */
+typedef struct fdevent_cmd_pipe {
+ pid_t pid;
+ int fds[2];
+ const char *cmd;
+ time_t start;
+} fdevent_cmd_pipe;
+
+typedef struct fdevent_cmd_pipes {
+ fdevent_cmd_pipe *ptr;
+ size_t used;
+ size_t size;
+} fdevent_cmd_pipes;
+
+static fdevent_cmd_pipes cmd_pipes;
+
+
+static pid_t fdevent_open_logger_pipe_spawn(const char *logger, int rfd) {
char *args[4];
- int to_log_fds[2];
int devnull = fdevent_open_devnull();
pid_t pid;
@@ -549,31 +565,129 @@ static int fdevent_open_logger_pipe(const char *logger) {
return -1;
}
- if (pipe(to_log_fds)) {
- close(devnull);
- return -1;
- }
- fdevent_setfd_cloexec(to_log_fds[0]);
- fdevent_setfd_cloexec(to_log_fds[1]);
-
*(const char **)&args[0] = "/bin/sh";
*(const char **)&args[1] = "-c";
*(const char **)&args[2] = logger;
args[3] = NULL;
- pid = fdevent_fork_execve(args[0], args, NULL, to_log_fds[0], devnull, devnull, -1);
+ pid = fdevent_fork_execve(args[0], args, NULL, rfd, devnull, devnull, -1);
if (pid > 0) {
- /*(future: save pipe fds, pid, and command line to restart if child exits)*/
close(devnull);
- close(to_log_fds[0]);
- return to_log_fds[1];
}
else {
int errnum = errno;
close(devnull);
- close(to_log_fds[0]);
- close(to_log_fds[1]);
+ errno = errnum;
+ }
+ return pid;
+}
+
+
+static void fdevent_waitpid_logger_pipe(fdevent_cmd_pipe *fcp, time_t ts) {
+ pid_t pid = fcp->pid;
+ if (pid > 0) {
+ switch (waitpid(pid, NULL, WNOHANG)) {
+ case 0: return;
+ case -1: if (errno == EINTR) return; /* fall through */
+ default: break;
+ }
+ fcp->pid = -1;
+ }
+ if (fcp->start + 5 < ts) { /* limit restart to once every 5 sec */
+ /* restart child process using existing pipe fds */
+ fcp->start = ts;
+ fcp->pid = fdevent_open_logger_pipe_spawn(fcp->cmd, fcp->fds[0]);
+ }
+}
+
+
+void fdevent_waitpid_logger_pipes(time_t ts) {
+ for (size_t i = 0; i < cmd_pipes.used; ++i) {
+ fdevent_waitpid_logger_pipe(cmd_pipes.ptr+i, ts);
+ }
+}
+
+
+int fdevent_reaped_logger_pipe(pid_t pid) {
+ for (size_t i = 0; i < cmd_pipes.used; ++i) {
+ fdevent_cmd_pipe *fcp = cmd_pipes.ptr+i;
+ if (fcp->pid == pid) {
+ time_t ts = time(NULL);
+ if (fcp->start + 5 < ts) { /* limit restart to once every 5 sec */
+ fcp->start = ts;
+ fcp->pid = fdevent_open_logger_pipe_spawn(fcp->cmd,fcp->fds[0]);
+ return 1;
+ }
+ else {
+ fcp->pid = -1;
+ return -1;
+ }
+ }
+ }
+ return 0;
+}
+
+
+void fdevent_close_logger_pipes(void) {
+ for (size_t i = 0; i < cmd_pipes.used; ++i) {
+ fdevent_cmd_pipe *fcp = cmd_pipes.ptr+i;
+ close(fcp->fds[0]);
+ if (fcp->fds[1] != STDERR_FILENO) close(fcp->fds[1]);
+ }
+ free(cmd_pipes.ptr);
+ cmd_pipes.ptr = NULL;
+ cmd_pipes.used = 0;
+ cmd_pipes.size = 0;
+}
+
+
+void fdevent_breakagelog_logger_pipe(int fd) {
+ for (size_t i = 0; i < cmd_pipes.used; ++i) {
+ fdevent_cmd_pipe *fcp = cmd_pipes.ptr+i;
+ if (fcp->fds[1] != fd) continue;
+ fcp->fds[1] = STDERR_FILENO;
+ break;
+ }
+}
+
+
+static void fdevent_init_logger_pipe(const char *cmd, int fds[2], pid_t pid) {
+ fdevent_cmd_pipe *fcp;
+ if (cmd_pipes.used == cmd_pipes.size) {
+ cmd_pipes.size += 4;
+ cmd_pipes.ptr =
+ realloc(cmd_pipes.ptr, cmd_pipes.size * sizeof(fdevent_cmd_pipe));
+ force_assert(cmd_pipes.ptr);
+ }
+ fcp = cmd_pipes.ptr + cmd_pipes.used++;
+ fcp->cmd = cmd; /* note: cmd must persist in memory (or else copy here) */
+ fcp->fds[0] = fds[0];
+ fcp->fds[1] = fds[1];
+ fcp->pid = pid;
+ fcp->start = time(NULL);
+}
+
+
+static int fdevent_open_logger_pipe(const char *logger) {
+ int fds[2];
+ pid_t pid;
+ if (pipe(fds)) {
+ return -1;
+ }
+ fdevent_setfd_cloexec(fds[0]);
+ fdevent_setfd_cloexec(fds[1]);
+
+ pid = fdevent_open_logger_pipe_spawn(logger, fds[0]);
+
+ if (pid > 0) {
+ fdevent_init_logger_pipe(logger, fds, pid);
+ return fds[1];
+ }
+ else {
+ int errnum = errno;
+ close(fds[0]);
+ close(fds[1]);
errno = errnum;
return -1;
}
diff --git a/src/fdevent.h b/src/fdevent.h
index bf9ba7c9..4caef9d9 100644
--- a/src/fdevent.h
+++ b/src/fdevent.h
@@ -225,6 +225,10 @@ int fdevent_set_stdin_stdout_stderr(int fdin, int fdout, int fderr);
pid_t fdevent_fork_execve(const char *name, char *argv[], char *envp[], int fdin, int fdout, int fderr, int dfd);
int fdevent_open_logger(const char *logger);
int fdevent_cycle_logger(const char *logger, int *curfd);
+int fdevent_reaped_logger_pipe(pid_t pid);
+void fdevent_waitpid_logger_pipes(time_t ts);
+void fdevent_close_logger_pipes(void);
+void fdevent_breakagelog_logger_pipe(int fd);
int fdevent_select_init(fdevents *ev);
int fdevent_poll_init(fdevents *ev);
diff --git a/src/mod_accesslog.c b/src/mod_accesslog.c
index 309579ed..9e299397 100644
--- a/src/mod_accesslog.c
+++ b/src/mod_accesslog.c
@@ -445,7 +445,11 @@ FREE_FUNC(mod_accesslog_free) {
}
}
- if (s->log_access_fd != -1) close(s->log_access_fd);
+ if (s->log_access_fd != -1) {
+ if (buffer_string_is_empty(s->access_logfile) || *s->access_logfile->ptr != '|') {
+ close(s->log_access_fd);
+ } /*(else piped loggers closed in fdevent_close_logger_pipes())*/
+ }
buffer_free(s->ts_accesslog_str);
buffer_free(s->access_logbuffer);
diff --git a/src/server.c b/src/server.c
index 18a71e4f..bad0b49d 100644
--- a/src/server.c
+++ b/src/server.c
@@ -843,6 +843,8 @@ static int log_error_open(server *srv) {
"' failed: ", strerror(errno));
return -1;
}
+
+ if (*logfile == '|') fdevent_breakagelog_logger_pipe(errfd);
}
else if (!srv->srvconf.dont_daemonize) {
/* move STDERR_FILENO to /dev/null */
@@ -900,8 +902,11 @@ static int log_error_close(server *srv) {
case ERRORLOG_FD:
if (-1 != srv->errorlog_fd) {
/* don't close STDERR */
- if (STDERR_FILENO != srv->errorlog_fd)
+ /* fdevent_close_logger_pipes() closes ERRORLOG_PIPE */
+ if (STDERR_FILENO != srv->errorlog_fd
+ && srv->errorlog_mode != ERRORLOG_PIPE) {
close(srv->errorlog_fd);
+ }
srv->errorlog_fd = -1;
}
break;
@@ -1598,6 +1603,11 @@ static int server_main (server * const srv, int argc, char **argv) {
int status;
if (-1 != (pid = wait(&status))) {
+ switch (fdevent_reaped_logger_pipe(pid)) {
+ default: break;
+ case -1: alarm(5); /* fall through */
+ case 1: continue;
+ }
/**
* check if one of our workers went away
*/
@@ -1630,6 +1640,10 @@ static int server_main (server * const srv, int argc, char **argv) {
kill(0, SIGHUP);
}
}
+ if (handle_sig_alarm) {
+ handle_sig_alarm = 0;
+ fdevent_waitpid_logger_pipes(time(NULL));
+ }
break;
default:
break;
@@ -1844,6 +1858,8 @@ static int server_main (server * const srv, int argc, char **argv) {
for (i = 0; i < srv->config_context->used; ++i) {
srv->config_storage[i]->global_bytes_per_second_cnt = 0;
}
+ /* check piped-loggers and restart, unless shutting down */
+ if (!graceful_shutdown && !srv_shutdown && 0 == srv->srvconf.max_worker) fdevent_waitpid_logger_pipes(min_ts);
/* if graceful_shutdown, accelerate cleanup of recently completed request/responses */
if (graceful_shutdown && !srv_shutdown) server_graceful_shutdown_maint(srv);
/**
@@ -2095,6 +2111,7 @@ int main (int argc, char **argv) {
/* clean-up */
remove_pid_file(srv);
log_error_close(srv);
+ fdevent_close_logger_pipes();
if (graceful_restart)
server_sockets_save(srv);
else