Make /dev/kmsg symlinking optional, add lxc.kmsg option

src/lxc/conf.c

@@ -2768,8 +2768,10 @@ int lxc_setup(const char *name, struct lxc_conf *lxc_conf)
 		return -1;
 	}
 
-	if (setup_kmsg(&lxc_conf->rootfs, &lxc_conf->console))  // don't fail
-		ERROR("failed to setup kmsg for '%s'", name);
+	if (lxc_conf->kmsg) {
+		if (setup_kmsg(&lxc_conf->rootfs, &lxc_conf->console))  // don't fail
+			ERROR("failed to setup kmsg for '%s'", name);
+	}
 
 	if (setup_tty(&lxc_conf->rootfs, &lxc_conf->tty_info, lxc_conf->ttydir)) {
 		ERROR("failed to setup the ttys for '%s'", name);

src/lxc/conf.h

@@ -278,6 +278,7 @@ struct lxc_conf {
 	int maincmd_fd;
 	int autodev;  // if 1, mount and fill a /dev at start
 	int stopsignal; // signal used to stop container
+	int kmsg;  // if 1, create /dev/kmsg symlink
 	char *rcfile;	// Copy of the top level rcfile we read
 };
 

src/lxc/confile.c

@@ -56,6 +56,7 @@ static int config_personality(const char *, const char *, struct lxc_conf *);
 static int config_pts(const char *, const char *, struct lxc_conf *);
 static int config_tty(const char *, const char *, struct lxc_conf *);
 static int config_ttydir(const char *, const char *, struct lxc_conf *);
+static int config_kmsg(const char *, const char *, struct lxc_conf *);
 #if HAVE_APPARMOR
 static int config_aa_profile(const char *, const char *, struct lxc_conf *);
 #endif
@@ -97,6 +98,7 @@ static struct lxc_config_t config[] = {
 	{ "lxc.pts",                  config_pts                  },
 	{ "lxc.tty",                  config_tty                  },
 	{ "lxc.devttydir",            config_ttydir               },
+	{ "lxc.kmsg",                 config_kmsg                 },
 #if HAVE_APPARMOR
 	{ "lxc.aa_profile",            config_aa_profile          },
 #endif
@@ -933,6 +935,16 @@ static int config_ttydir(const char *key, const char *value,
 	return 0;
 }
 
+static int config_kmsg(const char *key, const char *value,
+			  struct lxc_conf *lxc_conf)
+{
+	int v = atoi(value);
+
+	lxc_conf->kmsg = v;
+
+	return 0;
+}
+
 #if HAVE_APPARMOR
 static int config_aa_profile(const char *key, const char *value,
 			     struct lxc_conf *lxc_conf)