[lxc-devel] [lxc/master] lxc-init: log to /dev/console

brauner on Github lxc-bot at linuxcontainers.org
Sun Oct 14 20:23:35 UTC 2018


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From d3d21e4208aa356891e579c88a382d9645256cd3 Mon Sep 17 00:00:00 2001
From: Christian Brauner <christian.brauner at ubuntu.com>
Date: Sun, 14 Oct 2018 22:22:21 +0200
Subject: [PATCH] lxc-init: log to /dev/console

Signed-off-by: Christian Brauner <christian.brauner at ubuntu.com>
---
 src/lxc/Makefile.am    |   1 -
 src/lxc/cmd/lxc_init.c | 114 +++++++++++++++++------------------------
 src/lxc/execute.c      |  41 +--------------
 3 files changed, 48 insertions(+), 108 deletions(-)

diff --git a/src/lxc/Makefile.am b/src/lxc/Makefile.am
index 5a0ae9dd4..8ca9caabe 100644
--- a/src/lxc/Makefile.am
+++ b/src/lxc/Makefile.am
@@ -344,7 +344,6 @@ init_lxc_SOURCES = cmd/lxc_init.c \
 		   compiler.h \
 		   error.h \
 		   initutils.c initutils.h \
-		   log.c log.h \
 		   parse.c parse.h \
 		   raw_syscalls.c raw_syscalls.h \
 		   string_utils.c string_utils.h
diff --git a/src/lxc/cmd/lxc_init.c b/src/lxc/cmd/lxc_init.c
index 14cc5fd61..81aaca7a4 100644
--- a/src/lxc/cmd/lxc_init.c
+++ b/src/lxc/cmd/lxc_init.c
@@ -26,6 +26,7 @@
 #endif
 #include <ctype.h>
 #include <errno.h>
+#include <fcntl.h>
 #include <getopt.h>
 #include <libgen.h>
 #include <limits.h>
@@ -46,7 +47,6 @@
 #include "config.h"
 #include "error.h"
 #include "initutils.h"
-#include "log.h"
 #include "parse.h"
 #include "raw_syscalls.h"
 #include "string_utils.h"
@@ -58,7 +58,7 @@
 #define QUOTE(macro) #macro
 #define QUOTEVAL(macro) QUOTE(macro)
 
-lxc_log_define(lxc_init, lxc);
+extern int lxc_log_fd;
 
 static sig_atomic_t was_interrupted;
 
@@ -74,8 +74,6 @@ static struct option long_options[] = {
 	    { "usage",       no_argument,       0, OPT_USAGE   },
 	    { "version",     no_argument,       0, OPT_VERSION },
 	    { "quiet",       no_argument,       0, 'q'         },
-	    { "logfile",     required_argument, 0, 'o'         },
-	    { "logpriority", required_argument, 0, 'l'         },
 	    { "lxcpath",     required_argument, 0, 'P'         },
 	    { 0,             0,                 0, 0           }
 	};
@@ -86,8 +84,6 @@ struct arguments {
 	const char *shortopts;
 
 	const char *name;
-	char *log_file;
-	char *log_priority;
 	bool quiet;
 	const char *lxcpath;
 
@@ -142,19 +138,21 @@ static void prevent_forking(void)
 		ret = snprintf(path, sizeof(path),
 			       "/sys/fs/cgroup/pids/%s/pids.max", p2);
 		if (ret < 0 || (size_t)ret >= sizeof(path)) {
-			ERROR("Failed to create string");
+			if (my_args.quiet)
+				fprintf(stderr, "Failed to create string\n");
 			goto on_error;
 		}
 
 		fd = open(path, O_WRONLY);
 		if (fd < 0) {
-			SYSERROR("Failed to open \"%s\"", path);
+			if (my_args.quiet)
+				fprintf(stderr, "Failed to open \"%s\"\n", path);
 			goto on_error;
 		}
 
 		ret = write(fd, "1", 1);
-		if (ret != 1)
-			SYSERROR("Failed to write to \"%s\"", path);
+		if (ret != 1 && !my_args.quiet)
+			fprintf(stderr, "Failed to write to \"%s\"\n", path);
 
 		close(fd);
 		break;
@@ -173,13 +171,15 @@ static void kill_children(pid_t pid)
 
 	ret = snprintf(path, sizeof(path), "/proc/%d/task/%d/children", pid, pid);
 	if (ret < 0 || (size_t)ret >= sizeof(path)) {
-		ERROR("Failed to create string");
+		if (my_args.quiet)
+			fprintf(stderr, "Failed to create string\n");
 		return;
 	}
 
 	f = fopen(path, "r");
 	if (!f) {
-		SYSERROR("Failed to open %s", path);
+		if (my_args.quiet)
+			fprintf(stderr, "Failed to open %s\n", path);
 		return;
 	}
 
@@ -187,7 +187,8 @@ static void kill_children(pid_t pid)
 		pid_t pid;
 
 		if (fscanf(f, "%d ", &pid) != 1) {
-			ERROR("Failed to retrieve pid");
+			if (my_args.quiet)
+				fprintf(stderr, "Failed to retrieve pid\n");
 			fclose(f);
 			return;
 		}
@@ -206,51 +207,33 @@ static void remove_self(void)
 	char path[PATH_MAX] = {0};
 
 	n = readlink("/proc/self/exe", path, sizeof(path));
-	if (n < 0 || n >= PATH_MAX) {
-		SYSDEBUG("Failed to readlink \"/proc/self/exe\"");
+	if (n < 0 || n >= PATH_MAX)
 		return;
-	}
 	path[n] = '\0';
 
 	ret = umount2(path, MNT_DETACH);
-	if (ret < 0) {
-		SYSDEBUG("Failed to unmount \"%s\"", path);
+	if (ret < 0)
 		return;
-	}
 
 	ret = unlink(path);
-	if (ret < 0) {
-		SYSDEBUG("Failed to unlink \"%s\"", path);
+	if (ret < 0)
 		return;
-	}
 }
 
 int main(int argc, char *argv[])
 {
-	int i, ret;
-	pid_t pid, sid;
+	int i, logfd, ret;
+	pid_t pid;
 	struct sigaction act;
-	struct lxc_log log;
 	sigset_t mask, omask;
 	int have_status = 0, exit_with = 1, shutdown = 0;
 
 	if (arguments_parse(&my_args, argc, argv))
 		exit(EXIT_FAILURE);
 
-	log.prefix = "lxc-init";
-	log.name = my_args.name;
-	log.file = my_args.log_file;
-	log.level = my_args.log_priority;
-	log.quiet = my_args.quiet;
-	log.lxcpath = my_args.lxcpath;
-
-	ret = lxc_log_init(&log);
-	if (ret < 0)
-		exit(EXIT_FAILURE);
-	lxc_log_options_no_override();
-
 	if (!my_args.argc) {
-		ERROR("Please specify a command to execute");
+		if (my_args.quiet)
+			fprintf(stderr, "Please specify a command to execute\n");
 		exit(EXIT_FAILURE);
 	}
 
@@ -319,7 +302,8 @@ int main(int argc, char *argv[])
 			if (errno == EINVAL)
 				continue;
 
-			SYSERROR("Failed to change signal action");
+			if (my_args.quiet)
+				fprintf(stderr, "Failed to change signal action\n");
 			exit(EXIT_FAILURE);
 		}
 	}
@@ -340,34 +324,34 @@ int main(int argc, char *argv[])
 				continue;
 
 			sigerr = signal(i, SIG_DFL);
-			if (sigerr == SIG_ERR) {
-				SYSDEBUG("Failed to reset to default action "
-					 "for signal \"%d\": %d", i, pid);
-			}
+			if (sigerr == SIG_ERR && !my_args.quiet)
+				fprintf(stderr, "Failed to reset to default action for signal \"%d\": %d\n", i, pid);
 		}
 
 		ret = pthread_sigmask(SIG_SETMASK, &omask, NULL);
 		if (ret < 0) {
-			SYSERROR("Failed to set signal mask");
+			if (my_args.quiet)
+				fprintf(stderr, "Failed to set signal mask\n");
 			exit(EXIT_FAILURE);
 		}
 
-		sid = setsid();
-		if (sid < 0)
-			DEBUG("Failed to make child session leader");
+		(void)setsid();
 
-		if (ioctl(STDIN_FILENO, TIOCSCTTY, 0) < 0)
-			DEBUG("Failed to set controlling terminal");
-
-		NOTICE("Exec'ing \"%s\"", my_args.argv[0]);
+		(void)ioctl(STDIN_FILENO, TIOCSCTTY, 0);
 
 		ret = execvp(my_args.argv[0], my_args.argv);
-		SYSERROR("Failed to exec \"%s\"", my_args.argv[0]);
+		if (my_args.quiet)
+			fprintf(stderr, "Failed to exec \"%s\"\n", my_args.argv[0]);
 		exit(ret);
 	}
+	logfd = open("/dev/console", O_WRONLY | O_NOCTTY | O_CLOEXEC);
+	if (logfd >= 0) {
+		ret = dup3(logfd, STDERR_FILENO, O_CLOEXEC);
+		if (ret < 0)
+			exit(EXIT_FAILURE);
+	}
 
-	INFO("Attempting to set proc title to \"init\"");
-	setproctitle("init");
+	(void)setproctitle("init");
 
 	/* Let's process the signals now. */
 	ret = sigdelset(&omask, SIGALRM);
@@ -376,7 +360,8 @@ int main(int argc, char *argv[])
 
 	ret = pthread_sigmask(SIG_SETMASK, &omask, NULL);
 	if (ret < 0) {
-		SYSERROR("Failed to set signal mask");
+		if (my_args.quiet)
+			fprintf(stderr, "Failed to set signal mask\n");
 		exit(EXIT_FAILURE);
 	}
 
@@ -413,8 +398,8 @@ int main(int argc, char *argv[])
 					kill_children(mypid);
 				} else {
 					ret = kill(-1, SIGTERM);
-					if (ret < 0)
-						SYSDEBUG("Failed to send SIGTERM to all children");
+					if (ret < 0 && !my_args.quiet)
+						fprintf(stderr, "Failed to send SIGTERM to all children\n");
 				}
 				alarm(1);
 			}
@@ -427,15 +412,13 @@ int main(int argc, char *argv[])
 				kill_children(mypid);
 			} else {
 				ret = kill(-1, SIGKILL);
-				if (ret < 0)
-					SYSDEBUG("Failed to send SIGTERM to all children");
+				if (ret < 0 && !my_args.quiet)
+					fprintf(stderr, "Failed to send SIGTERM to all children\n");
 			}
 			break;
 		}
 		default:
 			ret = kill(pid, was_interrupted);
-			if (ret < 0)
-				SYSDEBUG("Failed to send signal \"%d\" to %d", was_interrupted, pid);
 			break;
 		}
 		ret = EXIT_SUCCESS;
@@ -449,7 +432,8 @@ int main(int argc, char *argv[])
 			if (errno == EINTR)
 				continue;
 
-			SYSERROR("Failed to wait on child %d", pid);
+			if (my_args.quiet)
+				fprintf(stderr, "Failed to wait on child %d\n", pid);
 			goto out;
 		}
 
@@ -475,7 +459,7 @@ __noreturn static void print_usage_exit(const struct option longopts[])
 
 {
 	fprintf(stderr, "Usage: lxc-init [-n|--name=NAME] [-h|--help] [--usage] [--version]\n\
-		[-q|--quiet] [-o|--logfile=LOGFILE] [-l|--logpriority=LOGPRIORITY] [-P|--lxcpath=LXCPATH]\n");
+		[-q|--quiet] [-P|--lxcpath=LXCPATH]\n");
 	exit(0);
 }
 
@@ -494,8 +478,6 @@ Usage: lxc-init --name=NAME -- COMMAND\n\
 \n\
 Options :\n\
   -n, --name=NAME                  NAME of the container\n\
-  -o, --logfile=FILE               Output log to FILE instead of stderr\n\
-  -l, --logpriority=LEVEL          Set log priority to LEVEL\n\
   -q, --quiet                      Don't produce any output\n\
   -P, --lxcpath=PATH               Use specified container path\n\
   -?, --help                       Give this help list\n\
@@ -523,10 +505,8 @@ static int arguments_parse(struct arguments *args, int argc,
 			args->name = optarg;
 			break;
 		case 'o':
-			args->log_file = optarg;
 			break;
 		case 'l':
-			args->log_priority = optarg;
 			break;
 		case 'q':
 			args->quiet = true;
diff --git a/src/lxc/execute.c b/src/lxc/execute.c
index b6e11ef68..45ca67e3a 100644
--- a/src/lxc/execute.c
+++ b/src/lxc/execute.c
@@ -44,10 +44,8 @@ static int execute_start(struct lxc_handler *handler, void* data)
 {
 	int argc_add, j;
 	char **argv;
-	int argc = 0, i = 0, logfd = -1;
+	int argc = 0, i = 0;
 	struct execute_args *my_args = data;
-	char logfile[LXC_PROC_PID_FD_LEN];
-	bool is_privileged = lxc_list_empty(&handler->conf->id_map);
 
 	while (my_args->argv[argc++]);
 
@@ -59,14 +57,6 @@ static int execute_start(struct lxc_handler *handler, void* data)
 	if (!handler->conf->rootfs.path)
 		argc_add += 2;
 
-	if (is_privileged) {
-		if (lxc_log_has_valid_level())
-			argc_add += 2;
-
-		if (current_config->logfd != -1 || lxc_log_fd != -1)
-			argc_add += 2;
-	}
-
 	argv = malloc((argc + argc_add) * sizeof(*argv));
 	if (!argv) {
 		SYSERROR("Allocating init args failed");
@@ -81,32 +71,6 @@ static int execute_start(struct lxc_handler *handler, void* data)
 	argv[i++] = "-n";
 	argv[i++] = (char *)handler->name;
 
-	if (lxc_log_has_valid_level()) {
-		argv[i++] = "-l";
-		argv[i++] = (char *)lxc_log_priority_to_string(lxc_log_get_level());
-	}
-
-	if (is_privileged && (current_config->logfd != -1 || lxc_log_fd != -1)) {
-		int ret;
-		int to_dup = current_config->logfd;
-
-		if (current_config->logfd == -1)
-			to_dup = lxc_log_fd;
-
-		logfd = dup(to_dup);
-		if (logfd < 0) {
-			SYSERROR("Failed to duplicate log file descriptor");
-			goto out2;
-		}
-
-		ret = snprintf(logfile, sizeof(logfile), "/proc/self/fd/%d", logfd);
-		if (ret < 0 || (size_t)ret >= sizeof(logfile))
-			goto out3;
-
-		argv[i++] = "-o";
-		argv[i++] = logfile;
-	}
-
 	if (my_args->quiet)
 		argv[i++] = "--quiet";
 
@@ -128,9 +92,6 @@ static int execute_start(struct lxc_handler *handler, void* data)
 		execvp(argv[0], argv);
 	SYSERROR("Failed to exec %s", argv[0]);
 
-out3:
-	close(logfd);
-out2:
 	free(argv);
 out1:
 	return 1;


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