lxc_start.c revision 596a818d4b8b55586d36af518b745cd96b24c67a
/*
* lxc: linux Container library
*
* (C) Copyright IBM Corp. 2007, 2008
*
* Authors:
* Daniel Lezcano <dlezcano at fr.ibm.com>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#define _GNU_SOURCE
#include <stdio.h>
#undef _GNU_SOURCE
#include <libgen.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <termios.h>
#include <errno.h>
#include <fcntl.h>
#include <signal.h>
#include <sys/param.h>
#include <sys/utsname.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/stat.h>
#include <arpa/inet.h>
#include <netinet/in.h>
#include <net/if.h>
#include "log.h"
#include "caps.h"
#include "lxc.h"
#include "conf.h"
#include "cgroup.h"
#include "utils.h"
#include "config.h"
#include "confile.h"
#include "arguments.h"
lxc_log_define(lxc_start_ui, lxc_start);
static struct lxc_list defines;
static int ensure_path(char **confpath, const char *path)
{
int err = -1, fd;
char *fullpath = NULL;
if (path) {
if (access(path, W_OK)) {
fd = creat(path, 0600);
if (fd < 0) {
SYSERROR("failed to create '%s'", path);
goto err;
}
close(fd);
}
fullpath = realpath(path, NULL);
if (!fullpath) {
SYSERROR("failed to get the real path of '%s'", path);
goto err;
}
*confpath = strdup(fullpath);
if (!*confpath) {
ERROR("failed to dup string '%s'", fullpath);
goto err;
}
}
err = 0;
err:
if (fullpath)
free(fullpath);
return err;
}
static int my_parser(struct lxc_arguments* args, int c, char* arg)
{
switch (c) {
case 'c': args->console = arg; break;
case 'L': args->console_log = arg; break;
case 'd': args->daemonize = 1; args->close_all_fds = 1; break;
case 'f': args->rcfile = arg; break;
case 'C': args->close_all_fds = 1; break;
case 's': return lxc_config_define_add(&defines, arg);
case 'p': args->pidfile = arg; break;
}
return 0;
}
static const struct option my_longopts[] = {
{"daemon", no_argument, 0, 'd'},
{"rcfile", required_argument, 0, 'f'},
{"define", required_argument, 0, 's'},
{"console", required_argument, 0, 'c'},
{"console-log", required_argument, 0, 'L'},
{"close-all-fds", no_argument, 0, 'C'},
{"pidfile", required_argument, 0, 'p'},
LXC_COMMON_OPTIONS
};
static struct lxc_arguments my_args = {
.progname = "lxc-start",
.help = "\
--name=NAME -- COMMAND\n\
\n\
lxc-start start COMMAND in specified container NAME\n\
\n\
Options :\n\
-n, --name=NAME NAME for name of the container\n\
-d, --daemon daemonize the container\n\
-p, --pidfile=FILE Create a file with the process id\n\
-f, --rcfile=FILE Load configuration file FILE\n\
-c, --console=FILE Use specified FILE for the container console\n\
-L, --console-log=FILE Log container console output to FILE\n\
-C, --close-all-fds If any fds are inherited, close them\n\
If not specified, exit with failure instead\n\
Note: --daemon implies --close-all-fds\n\
-s, --define KEY=VAL Assign VAL to configuration variable KEY\n",
.options = my_longopts,
.parser = my_parser,
.checker = NULL,
.daemonize = 0,
.pidfile = NULL,
};
int main(int argc, char *argv[])
{
int err = -1;
struct lxc_conf *conf;
char *const *args;
char *rcfile = NULL;
char *const default_args[] = {
"/sbin/init",
'\0',
};
FILE *pid_fp = NULL;
lxc_list_init(&defines);
if (lxc_caps_init())
return err;
if (lxc_arguments_parse(&my_args, argc, argv))
return err;
if (!my_args.argc)
args = default_args;
else
args = my_args.argv;
if (lxc_log_init(my_args.log_file, my_args.log_priority,
my_args.progname, my_args.quiet))
return err;
if (clearenv()) {
SYSERROR("failed to clear environment");
/* don't error out though */
}
if (putenv("container=lxc")) {
SYSERROR("failed to set environment variable");
return err;
}
/* rcfile is specified in the cli option */
if (my_args.rcfile)
rcfile = (char *)my_args.rcfile;
else {
int rc;
rc = asprintf(&rcfile, LXCPATH "/%s/config", my_args.name);
if (rc == -1) {
SYSERROR("failed to allocate memory");
return err;
}
/* container configuration does not exist */
if (access(rcfile, F_OK)) {
free(rcfile);
rcfile = NULL;
}
}
conf = lxc_conf_init();
if (!conf) {
ERROR("failed to initialize configuration");
return err;
}
if (rcfile && lxc_config_read(rcfile, conf)) {
ERROR("failed to read configuration file");
return err;
}
if (lxc_config_define_load(&defines, conf))
return err;
if (!rcfile && !strcmp("/sbin/init", args[0])) {
ERROR("no configuration file for '/sbin/init' (may crash the host)");
return err;
}
if (ensure_path(&conf->console.path, my_args.console) < 0) {
ERROR("failed to ensure console path '%s'", my_args.console);
return err;
}
if (ensure_path(&conf->console.log_path, my_args.console_log) < 0) {
ERROR("failed to ensure console log '%s'", my_args.console_log);
return err;
}
if (my_args.pidfile != NULL) {
pid_fp = fopen(my_args.pidfile, "w");
if (pid_fp == NULL) {
SYSERROR("failed to create pidfile '%s' for '%s'",
my_args.pidfile, my_args.name);
return err;
}
}
if (my_args.daemonize) {
/* do an early check for needed privs, since otherwise the
* user won't see the error */
if (!lxc_caps_check()) {
ERROR("Not running with sufficient privilege");
return err;
}
if (daemon(0, 0)) {
SYSERROR("failed to daemonize '%s'", my_args.name);
return err;
}
}
if (pid_fp != NULL) {
if (fprintf(pid_fp, "%d\n", getpid()) < 0) {
SYSERROR("failed to write '%s'", my_args.pidfile);
return err;
}
fclose(pid_fp);
}
if (my_args.close_all_fds)
conf->close_all_fds = 1;
err = lxc_start(my_args.name, args, conf);
/*
* exec ourself, that requires to have all opened fd
* with the close-on-exec flag set
*/
if (conf->reboot) {
INFO("rebooting container");
execvp(argv[0], argv);
SYSERROR("failed to exec");
err = -1;
}
if (my_args.pidfile)
unlink(my_args.pidfile);
return err;
}