lxc_monitord: improve log + set log level to DEBUG

Setting loglevel to DEBUG will allow us to retrieve more useful information in
case something goes wrong. The total size of the log will not increase
significantly.

Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>

diff --git a/src/lxc/lxc_monitord.c b/src/lxc/lxc_monitord.c
index 61c8411fbd7c0948eb8b3bda0d5d0edff95b7c80..2500571c26aac59c98c6ff0b23e1a926b987dc81 100644 (file)
--- a/src/lxc/lxc_monitord.c
+++ b/src/lxc/lxc_monitord.c
@@ -22,21 +22,21 @@
  */
 
 #define _GNU_SOURCE
-#include <stdio.h>
-#include <signal.h>
 #include <errno.h>
-#include <unistd.h>
-#include <string.h>
-#include <stdlib.h>
 #include <fcntl.h>
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <net/if.h>
+#include <netinet/in.h>
 #include <sys/epoll.h>
-#include <sys/types.h>
-#include <sys/stat.h>
 #include <sys/param.h>
 #include <sys/socket.h>
+#include <sys/stat.h>
+#include <sys/types.h>
 #include <sys/un.h>
-#include <netinet/in.h>
-#include <net/if.h>
 
 #include "af_unix.h"
 #include "log.h"
@@ -85,14 +85,14 @@ static int lxc_monitord_fifo_create(struct lxc_monitor *mon)
 
        ret = mknod(fifo_path, S_IFIFO|S_IRUSR|S_IWUSR, 0);
        if (ret < 0 && errno != EEXIST) {
-               INFO("failed to mknod monitor fifo %s %s", fifo_path, strerror(errno));
+               INFO("Failed to mknod monitor fifo %s: %s.", fifo_path, strerror(errno));
                return -1;
        }
 
        mon->fifofd = open(fifo_path, O_RDWR);
        if (mon->fifofd < 0) {
                unlink(fifo_path);
-               ERROR("failed to open monitor fifo");
+               ERROR("Failed to open monitor fifo.");
                return -1;
        }
 
@@ -102,7 +102,7 @@ static int lxc_monitord_fifo_create(struct lxc_monitor *mon)
        lk.l_len = 0;
        if (fcntl(mon->fifofd, F_SETLK, &lk) != 0) {
                /* another lxc-monitord is already running, don't start up */
-               DEBUG("lxc-monitord already running on lxcpath %s", mon->lxcpath);
+               DEBUG("lxc-monitord already running on lxcpath %s.", mon->lxcpath);
                close(mon->fifofd);
                return -1;
        }
@@ -126,7 +126,7 @@ static void lxc_monitord_sockfd_remove(struct lxc_monitor *mon, int fd) {
        int i;
 
        if (lxc_mainloop_del_handler(&mon->descr, fd))
-               CRIT("fd:%d not found in mainloop", fd);
+               CRIT("File descriptor %d not found in mainloop.", fd);
        close(fd);
 
        for (i = 0; i < mon->clientfds_cnt; i++) {
@@ -134,7 +134,7 @@ static void lxc_monitord_sockfd_remove(struct lxc_monitor *mon, int fd) {
                        break;
        }
        if (i >= mon->clientfds_cnt) {
-               CRIT("fd:%d not found in clients array", fd);
+               CRIT("File descriptor %d not found in clients array.", fd);
                lxc_monitord_cleanup();
                exit(EXIT_FAILURE);
        }
@@ -174,35 +174,34 @@ static int lxc_monitord_sock_accept(int fd, uint32_t events, void *data,
        ret = -1;
        clientfd = accept(fd, NULL, 0);
        if (clientfd < 0) {
-               SYSERROR("failed to accept connection");
+               SYSERROR("Failed to accept connection for client file descriptor %d.", fd);
                goto out;
        }
 
        if (fcntl(clientfd, F_SETFD, FD_CLOEXEC)) {
-               SYSERROR("failed to set close-on-exec on incoming connection");
+               SYSERROR("Failed to set FD_CLOEXEC on client socket connection %d.", clientfd);
                goto err1;
        }
 
        if (getsockopt(clientfd, SOL_SOCKET, SO_PEERCRED, &cred, &credsz))
        {
-               ERROR("failed to get credentials on socket");
+               ERROR("Failed to get credentials on client socket connection %d.", clientfd);
                goto err1;
        }
        if (cred.uid && cred.uid != geteuid()) {
-               WARN("monitor denied for uid:%d", cred.uid);
+               WARN("Monitor denied for uid %d on client socket connection %d.", cred.uid, clientfd);
                ret = -EACCES;
                goto err1;
        }
 
        if (mon->clientfds_cnt + 1 > mon->clientfds_size) {
                int *clientfds;
-               DEBUG("realloc space for %d clientfds",
-                     mon->clientfds_size + CLIENTFDS_CHUNK);
                clientfds = realloc(mon->clientfds,
-                                   (mon->clientfds_size + CLIENTFDS_CHUNK) *
-                                    sizeof(mon->clientfds[0]));
+                                   (mon->clientfds_size + CLIENTFDS_CHUNK) * sizeof(mon->clientfds[0]));
                if (clientfds == NULL) {
-                       ERROR("failed to realloc memory for clientfds");
+                       ERROR("Failed to realloc memory for %d client file "
+                             "descriptors.",
+                             mon->clientfds_size + CLIENTFDS_CHUNK);
                        goto err1;
                }
                mon->clientfds = clientfds;
@@ -212,12 +211,12 @@ static int lxc_monitord_sock_accept(int fd, uint32_t events, void *data,
        ret = lxc_mainloop_add_handler(&mon->descr, clientfd,
                                       lxc_monitord_sock_handler, mon);
        if (ret) {
-               ERROR("failed to add socket handler");
+               ERROR("Failed to add socket handler.");
                goto err1;
        }
 
        mon->clientfds[mon->clientfds_cnt++] = clientfd;
-       INFO("accepted client fd:%d clients:%d", clientfd, mon->clientfds_cnt);
+       INFO("Accepted client file descriptor %d. Number of accepted file descriptors is now %d.", clientfd, mon->clientfds_cnt);
        goto out;
 
 err1:
@@ -236,7 +235,7 @@ static int lxc_monitord_sock_create(struct lxc_monitor *mon)
 
        fd = lxc_abstract_unix_open(addr.sun_path, SOCK_STREAM, O_TRUNC);
        if (fd < 0) {
-               ERROR("failed to open unix socket : %s", strerror(errno));
+               ERROR("Failed to open unix socket: %s.", strerror(errno));
                return -1;
        }
 
@@ -295,17 +294,15 @@ static int lxc_monitord_fifo_handler(int fd, uint32_t events, void *data,
 
        ret = read(fd, &msglxc, sizeof(msglxc));
        if (ret != sizeof(msglxc)) {
-               SYSERROR("read fifo failed : %s", strerror(errno));
+               SYSERROR("Reading from fifo failed: %s.", strerror(errno));
                return 1;
        }
 
        for (i = 0; i < mon->clientfds_cnt; i++) {
-               DEBUG("writing client fd:%d", mon->clientfds[i]);
                ret = write(mon->clientfds[i], &msglxc, sizeof(msglxc));
-               if (ret < 0) {
-                       ERROR("write failed to client sock:%d %d %s",
-                             mon->clientfds[i], errno, strerror(errno));
-               }
+               if (ret < 0)
+                       ERROR("Failed to send message to client file descriptor %d: %s.",
+                             mon->clientfds[i], strerror(errno));
        }
 
        return 0;
@@ -318,14 +315,14 @@ static int lxc_monitord_mainloop_add(struct lxc_monitor *mon)
        ret = lxc_mainloop_add_handler(&mon->descr, mon->fifofd,
                                       lxc_monitord_fifo_handler, mon);
        if (ret < 0) {
-               ERROR("failed to add to mainloop monitor handler for fifo");
+               ERROR("Failed to add to mainloop monitor handler for fifo.");
                return -1;
        }
 
        ret = lxc_mainloop_add_handler(&mon->descr, mon->listenfd,
                                       lxc_monitord_sock_accept, mon);
        if (ret < 0) {
-               ERROR("failed to add to mainloop monitor handler for listen socket");
+               ERROR("Failed to add to mainloop monitor handler for listen socket.");
                return -1;
        }
 
@@ -339,17 +336,17 @@ static void lxc_monitord_cleanup(void)
 
 static void lxc_monitord_sig_handler(int sig)
 {
-       INFO("caught signal %d", sig);
+       INFO("Caught signal %d.", sig);
        lxc_monitord_cleanup();
        exit(EXIT_SUCCESS);
 }
 
 int main(int argc, char *argv[])
 {
-       int ret,pipefd;
-       char *lxcpath = argv[1];
+       int ret, pipefd;
        char logpath[PATH_MAX];
        sigset_t mask;
+       char *lxcpath = argv[1];
 
        if (argc != 3) {
                fprintf(stderr,
@@ -360,13 +357,13 @@ int main(int argc, char *argv[])
        }
 
        ret = snprintf(logpath, sizeof(logpath), "%s/lxc-monitord.log",
-                      (strcmp(LXCPATH, lxcpath) ? lxcpath : LOGPATH ) );
+                      (strcmp(LXCPATH, lxcpath) ? lxcpath : LOGPATH ));
        if (ret < 0 || ret >= sizeof(logpath))
                exit(EXIT_FAILURE);
 
-       ret = lxc_log_init(NULL, logpath, "NOTICE", "lxc-monitord", 0, lxcpath);
+       ret = lxc_log_init(NULL, logpath, "DEBUG", "lxc-monitord", 0, lxcpath);
        if (ret)
-               INFO("Failed to open log file %s, log will be lost", lxcpath);
+               INFO("Failed to open log file %s, log will be lost.", lxcpath);
        lxc_log_options_no_override();
 
        if (lxc_safe_int(argv[2], &pipefd) < 0)
@@ -378,7 +375,7 @@ int main(int argc, char *argv[])
            sigdelset(&mask, SIGBUS)  ||
            sigdelset(&mask, SIGTERM) ||
            sigprocmask(SIG_BLOCK, &mask, NULL)) {
-               SYSERROR("failed to set signal mask");
+               SYSERROR("Failed to set signal mask.");
                exit(EXIT_FAILURE);
        }
 
@@ -391,12 +388,12 @@ int main(int argc, char *argv[])
        memset(&mon, 0, sizeof(mon));
        mon.lxcpath = lxcpath;
        if (lxc_mainloop_open(&mon.descr)) {
-               ERROR("failed to create mainloop");
-               goto out;
+               ERROR("Failed to create mainloop.");
+               goto on_error;
        }
 
        if (lxc_monitord_create(&mon)) {
-               goto out;
+               goto on_error;
        }
 
        /* sync with parent, we're ignoring the return from write
@@ -410,16 +407,16 @@ int main(int argc, char *argv[])
        close(pipefd);
 
        if (lxc_monitord_mainloop_add(&mon)) {
-               ERROR("failed to add mainloop handlers");
-               goto out;
+               ERROR("Failed to add mainloop handlers.");
+               goto on_error;
        }
 
-       NOTICE("pid:%d monitoring lxcpath %s", getpid(), mon.lxcpath);
-       for(;;) {
+       NOTICE("lxc-monitord with pid %d is now monitoring lxcpath %s.",
+              getpid(), mon.lxcpath);
+       for (;;) {
                ret = lxc_mainloop(&mon.descr, 1000 * 30);
-               if (mon.clientfds_cnt <= 0)
-               {
-                       NOTICE("no remaining clients, exiting");
+               if (mon.clientfds_cnt <= 0) {
+                       NOTICE("No remaining clients. lxc-monitord is exiting.");
                        break;
                }
        }
@@ -427,7 +424,7 @@ int main(int argc, char *argv[])
        lxc_mainloop_close(&mon.descr);
        lxc_monitord_cleanup();
        ret = EXIT_SUCCESS;
-       NOTICE("monitor exiting");
-out:
+
+on_error:
        exit(ret);
 }