[lxc-devel] [lxc/master] Add syslog support
bapt on Github
lxc-bot at linuxcontainers.org
Thu Jul 28 12:56:53 UTC 2016
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From 66611366a733aac3949f52f5ea4f2174d9546df0 Mon Sep 17 00:00:00 2001
From: Baptiste Daroussin <bapt at gandi.net>
Date: Fri, 8 Jul 2016 11:35:11 +0200
Subject: [PATCH 1/2] Add a new logger: syslog
To activate it specify lxc.syslog = <afacility>
For now the available facilities are: daemon, local[0-7] others will be
rejected
syslog got only activated after the function that checks for inheritance
of fd is passed in order to make sure the syslog fd is not inherited
and prevent the creation of the fd is any log have been issued during
the checks (which would end up in an infinite loop)
Signed-off-by: Fatih ACAR <fatih.acar at gandi.net>
Signed-off-by: Ahmed Amamou <ahmed at gandi.net>
Signed-off-by: Baptiste Daroussin <bapt at gandi.net>
Signed-off-by: William Dauchy <william at gandi.net>
---
src/lxc/confile.c | 37 +++++++++++++++++++++++
src/lxc/log.c | 87 +++++++++++++++++++++++++++++++++++++++++++++++++++++--
src/lxc/log.h | 2 ++
src/lxc/start.c | 7 +++++
4 files changed, 131 insertions(+), 2 deletions(-)
diff --git a/src/lxc/confile.c b/src/lxc/confile.c
index 14a76b2..c60714a 100644
--- a/src/lxc/confile.c
+++ b/src/lxc/confile.c
@@ -38,6 +38,7 @@
#include <net/if.h>
#include <time.h>
#include <dirent.h>
+#include <syslog.h>
#include "parse.h"
#include "config.h"
@@ -105,6 +106,7 @@ static int config_haltsignal(const char *, const char *, struct lxc_conf *);
static int config_rebootsignal(const char *, const char *, struct lxc_conf *);
static int config_stopsignal(const char *, const char *, struct lxc_conf *);
static int config_start(const char *, const char *, struct lxc_conf *);
+static int config_syslog(const char *, const char *, struct lxc_conf *);
static int config_monitor(const char *, const char *, struct lxc_conf *);
static int config_group(const char *, const char *, struct lxc_conf *);
static int config_environment(const char *, const char *, struct lxc_conf *);
@@ -184,6 +186,7 @@ static struct lxc_config_t config[] = {
{ "lxc.init_uid", config_init_uid },
{ "lxc.init_gid", config_init_gid },
{ "lxc.ephemeral", config_ephemeral },
+ { "lxc.syslog", config_syslog },
};
struct signame {
@@ -270,6 +273,23 @@ static const struct signame signames[] = {
#endif
};
+struct facilityname {
+ const char *name;
+ int facility;
+};
+
+static const struct facilityname facilitynames[] = {
+ { "daemon", LOG_DAEMON },
+ { "local0", LOG_LOCAL0 },
+ { "local1", LOG_LOCAL1 },
+ { "local2", LOG_LOCAL2 },
+ { "local3", LOG_LOCAL3 },
+ { "local4", LOG_LOCAL4 },
+ { "local5", LOG_LOCAL5 },
+ { "local6", LOG_LOCAL6 },
+ { "local7", LOG_LOCAL7 },
+};
+
static const size_t config_size = sizeof(config)/sizeof(struct lxc_config_t);
extern struct lxc_config_t *lxc_getconfig(const char *key)
@@ -2919,3 +2939,20 @@ static int config_ephemeral(const char *key, const char *value,
return 0;
}
+static int config_syslog(const char *key, const char *value,
+ struct lxc_conf *lxc_conf)
+{
+ int n;
+ int facility = -1;
+
+ for (n = 0; n < sizeof(facilitynames) / sizeof((facilitynames)[0]); n++) {
+ if (strcasecmp(facilitynames[n].name, value) == 0) {
+ facility = facilitynames[n].facility;
+ lxc_log_syslog(facility);
+ return 0;
+ }
+ }
+
+ ERROR("Wrong value for lxc.syslog");
+ return -1;
+}
diff --git a/src/lxc/log.c b/src/lxc/log.c
index 11d4bbf..4234679 100644
--- a/src/lxc/log.c
+++ b/src/lxc/log.c
@@ -20,6 +20,7 @@
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
+#define _GNU_SOURCE
#include <assert.h>
#include <stdio.h>
#include <errno.h>
@@ -30,8 +31,8 @@
#include <string.h>
#include <pthread.h>
#include <time.h>
-
-#define __USE_GNU /* for *_CLOEXEC */
+#include <syslog.h>
+#include <stdio.h>
#include <fcntl.h>
#include <stdlib.h>
@@ -43,6 +44,7 @@
#define LXC_LOG_DATEFOMAT_SIZE 15
int lxc_log_fd = -1;
+static int syslog_enable = 0;
int lxc_quiet_specified;
int lxc_log_use_global_fd;
static int lxc_loglevel_specified;
@@ -52,6 +54,58 @@ static char *log_fname = NULL;
lxc_log_define(lxc_log, lxc);
+static int lxc_log_priority_to_syslog(int priority)
+{
+ switch (priority) {
+ case LXC_LOG_PRIORITY_FATAL:
+ return LOG_EMERG;
+ case LXC_LOG_PRIORITY_ALERT:
+ return LOG_ALERT;
+ case LXC_LOG_PRIORITY_CRIT:
+ return LOG_CRIT;
+ case LXC_LOG_PRIORITY_ERROR:
+ return LOG_ERR;
+ case LXC_LOG_PRIORITY_WARN:
+ return LOG_WARNING;
+ case LXC_LOG_PRIORITY_NOTICE:
+ case LXC_LOG_PRIORITY_NOTSET:
+ return LOG_NOTICE;
+ case LXC_LOG_PRIORITY_INFO:
+ return LOG_INFO;
+ case LXC_LOG_PRIORITY_TRACE:
+ case LXC_LOG_PRIORITY_DEBUG:
+ return LOG_DEBUG;
+ }
+
+ /* Not reached */
+ return LOG_NOTICE;
+}
+
+/*---------------------------------------------------------------------------*/
+static int log_append_syslog(const struct lxc_log_appender *appender,
+ struct lxc_log_event *event)
+{
+ char *msg;
+ int rc;
+
+ if (!syslog_enable)
+ return 0;
+
+ rc = vasprintf(&msg, event->fmt, *event->vap);
+ if (rc == -1) {
+ return 0;
+ }
+
+ syslog(lxc_log_priority_to_syslog(event->priority),
+ "%s - %s:%s:%d - %s" ,
+ event->category,
+ event->locinfo->file, event->locinfo->func,
+ event->locinfo->line,
+ msg);
+ free(msg);
+ return 0;
+}
+
/*---------------------------------------------------------------------------*/
static int log_append_stderr(const struct lxc_log_appender *appender,
struct lxc_log_event *event)
@@ -115,6 +169,12 @@ static int log_append_logfile(const struct lxc_log_appender *appender,
return write(fd_to_use, buffer, n + 1);
}
+static struct lxc_log_appender log_appender_syslog = {
+ .name = "syslog",
+ .append = log_append_syslog,
+ .next = NULL,
+};
+
static struct lxc_log_appender log_appender_stderr = {
.name = "stderr",
.append = log_append_stderr,
@@ -253,6 +313,7 @@ static char *build_log_path(const char *name, const char *lxcpath)
extern void lxc_log_close(void)
{
+ closelog();
if (lxc_log_fd == -1)
return;
close(lxc_log_fd);
@@ -317,6 +378,28 @@ static int _lxc_log_set_file(const char *name, const char *lxcpath, int create_d
return ret;
}
+extern int lxc_log_syslog(int facility)
+{
+ struct lxc_log_appender *appender;
+
+ openlog(log_prefix, LOG_PID, facility);
+ if (!lxc_log_category_lxc.appender) {
+ lxc_log_category_lxc.appender = &log_appender_syslog;
+ return 0;
+ }
+ appender = lxc_log_category_lxc.appender;
+ while (appender->next != NULL)
+ appender = appender->next;
+ appender->next = &log_appender_syslog;
+
+ return 0;
+}
+
+extern void lxc_log_enable_syslog(void)
+{
+ syslog_enable = 1;
+}
+
/*
* lxc_log_init:
* Called from lxc front-end programs (like lxc-create, lxc-start) to
diff --git a/src/lxc/log.h b/src/lxc/log.h
index eb330d0..8906c23 100644
--- a/src/lxc/log.h
+++ b/src/lxc/log.h
@@ -314,6 +314,8 @@ extern int lxc_log_init(const char *name, const char *file,
const char *lxcpath);
extern int lxc_log_set_file(int *fd, const char *fname);
+extern int lxc_log_syslog(int facility);
+extern void lxc_log_enable_syslog(void);
extern int lxc_log_set_level(int *dest, int level);
extern void lxc_log_set_prefix(const char *prefix);
extern const char *lxc_log_get_file(void);
diff --git a/src/lxc/start.c b/src/lxc/start.c
index b3f75b8..1ba0f9b 100644
--- a/src/lxc/start.c
+++ b/src/lxc/start.c
@@ -255,6 +255,13 @@ int lxc_check_inherited(struct lxc_conf *conf, bool closeall, int fd_to_ignore)
WARN("inherited fd %d", fd);
}
+ /*
+ * only enable syslog at this point to avoid the above logging function
+ * to open a new fd and make the check_inherited function enter an
+ * infinite loop.
+ */
+ lxc_log_enable_syslog();
+
closedir(dir); /* cannot fail */
return 0;
}
From dac00b5d99b3f5ed1a71d531680aae3df7220a01 Mon Sep 17 00:00:00 2001
From: Baptiste Daroussin <bapt at gandi.net>
Date: Fri, 8 Jul 2016 18:12:56 +0200
Subject: [PATCH 2/2] Print the VM name in the logs
It helps debugging
Signed-off-by: Fatih ACAR <fatih.acar at gandi.net>
Signed-off-by: Ahmed Amamou <ahmed at gandi.net>
Signed-off-by: Baptiste Daroussin <bapt at gandi.net>
Signed-off-by: William Dauchy <william at gandi.net>
---
src/lxc/log.c | 15 ++++++++++++---
1 file changed, 12 insertions(+), 3 deletions(-)
diff --git a/src/lxc/log.c b/src/lxc/log.c
index 4234679..77b0606 100644
--- a/src/lxc/log.c
+++ b/src/lxc/log.c
@@ -51,6 +51,7 @@ static int lxc_loglevel_specified;
static char log_prefix[LXC_LOG_PREFIX_SIZE] = "lxc";
static char *log_fname = NULL;
+static char *log_vmname = NULL;
lxc_log_define(lxc_log, lxc);
@@ -97,7 +98,8 @@ static int log_append_syslog(const struct lxc_log_appender *appender,
}
syslog(lxc_log_priority_to_syslog(event->priority),
- "%s - %s:%s:%d - %s" ,
+ "%s %s - %s:%s:%d - %s" ,
+ log_vmname ? log_vmname : "",
event->category,
event->locinfo->file, event->locinfo->func,
event->locinfo->line,
@@ -113,7 +115,7 @@ static int log_append_stderr(const struct lxc_log_appender *appender,
if (event->priority < LXC_LOG_PRIORITY_ERROR)
return 0;
- fprintf(stderr, "%s: ", log_prefix);
+ fprintf(stderr, "%s: %s", log_prefix, log_vmname ? log_vmname : "");
fprintf(stderr, "%s: %s: %d ", event->locinfo->file, event->locinfo->func, event->locinfo->line);
vfprintf(stderr, event->fmt, *event->vap);
fprintf(stderr, "\n");
@@ -146,8 +148,10 @@ static int log_append_logfile(const struct lxc_log_appender *appender,
strftime(date, sizeof(date), "%Y%m%d%H%M%S", t);
ms = event->timestamp.tv_usec / 1000;
n = snprintf(buffer, sizeof(buffer),
- "%15s %10s.%03d %-8s %s - %s:%s:%d - ",
+ "%15s%s%s %10s.%03d %-8s %s - %s:%s:%d - ",
log_prefix,
+ log_vmname ? " " : "",
+ log_vmname ? log_vmname : "",
date,
ms,
lxc_log_priority_to_string(event->priority),
@@ -314,6 +318,8 @@ static char *build_log_path(const char *name, const char *lxcpath)
extern void lxc_log_close(void)
{
closelog();
+ free(log_vmname);
+ log_vmname = NULL;
if (lxc_log_fd == -1)
return;
close(lxc_log_fd);
@@ -433,6 +439,9 @@ extern int lxc_log_init(const char *name, const char *file,
if (prefix)
lxc_log_set_prefix(prefix);
+ if (name)
+ log_vmname = strdup(name);
+
if (file) {
if (strcmp(file, "none") == 0)
return 0;
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