src/lxc/lxc_restart.c

   1 /*
   2  * lxc: linux Container library
   3  *
   4  * (C) Copyright IBM Corp. 2007, 2010
   5  *
   6  * Authors:
   7  * Daniel Lezcano <dlezcano at fr.ibm.com>
   8  *
   9  * This library is free software; you can redistribute it and/or
  10  * modify it under the terms of the GNU Lesser General Public
  11  * License as published by the Free Software Foundation; either
  12  * version 2.1 of the License, or (at your option) any later version.
  13  *
  14  * This library is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  17  * Lesser General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU Lesser General Public
  20  * License along with this library; if not, write to the Free Software
  21  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  22  */
  23 #define _GNU_SOURCE
  24 #include <stdio.h>
  25 #undef _GNU_SOURCE
  26 #include <stdlib.h>
  27 #include <unistd.h>
  28 #include <errno.h>
  29 #include <sys/types.h>
  30 #include <fcntl.h>
  31
  32 #include "log.h"
  33 #include "lxc.h"
  34 #include "caps.h"
  35 #include "conf.h"
  36 #include "config.h"
  37 #include "confile.h"
  38 #include "arguments.h"
  39
  40 lxc_log_define(lxc_restart_ui, lxc_restart);
  41
  42 static struct lxc_list defines;
  43
  44 static int my_checker(const struct lxc_arguments* args)
  45 {
  46         if ((!args->statefile) && (args->statefd == -1)) {
  47                 lxc_error(args, "no statefile specified");
  48                 return -1;
  49         }
  50
  51         if ((args->statefile) && (args->statefd != -1)) {
  52                 lxc_error(args, "--statefile AND --statefd abnormally set");
  53                 return -1;
  54         }
  55
  56         return 0;
  57 }
  58
  59 static int my_parser(struct lxc_arguments* args, int c, char* arg)
  60 {
  61         switch (c) {
  62         case 'S': args->statefile = arg; break;
  63         case 'f': args->rcfile = arg; break;
  64         case 'p': args->flags = LXC_FLAG_PAUSE; break;
  65         case 's': return lxc_config_define_add(&defines, arg);
  66         case 'd': {
  67                         int fd;
  68                         fd = lxc_arguments_str_to_int(args, arg);
  69                         if (fd < 0)
  70                                 return -1;
  71
  72                         args->statefd = fd;
  73                         break;
  74                 }
  75         }
  76
  77         return 0;
  78 }
  79
  80 static const struct option my_longopts[] = {
  81         {"statefile", required_argument, 0, 'S'},
  82         {"statefd", required_argument, 0, 'd'},
  83         {"rcfile", required_argument, 0, 'f'},
  84         {"pause", no_argument, 0, 'p'},
  85         {"define", required_argument, 0, 's'},
  86         LXC_COMMON_OPTIONS
  87 };
  88
  89 static struct lxc_arguments my_args = {
  90         .progname = "lxc-restart",
  91         .help     = "\
  92 --name=NAME --statefile FILE\n\
  93 \n\
  94 lxc-restart restarts from FILE the NAME container\n\
  95 \n\
  96 Options :\n\
  97   -n, --name=NAME      NAME for name of the container\n\
  98   -p, --pause          do not unfreeze the container after the restart\n\
  99   -S, --statefile=FILE read the container state from this file, or\n\
 100   -d, --statefd=FD read the container state from this file descriptor\n\
 101   -f, --rcfile=FILE Load configuration file FILE\n\
 102   -s, --define KEY=VAL Assign VAL to configuration variable KEY\n",
 103         .options  = my_longopts,
 104         .parser   = my_parser,
 105         .checker  = my_checker,
 106
 107         .statefd  = -1,
 108 };
 109
 110 int main(int argc, char *argv[])
 111 {
 112         int sfd = -1;
 113         int ret;
 114         char *rcfile = NULL;
 115         struct lxc_conf *conf;
 116
 117         lxc_list_init(&defines);
 118
 119         if (lxc_caps_init())
 120                 return -1;
 121
 122         if (lxc_arguments_parse(&my_args, argc, argv))
 123                 return -1;
 124
 125         if (lxc_log_init(my_args.name, my_args.log_file, my_args.log_priority,
 126                          my_args.progname, my_args.quiet))
 127                 return -1;
 128
 129         /* rcfile is specified in the cli option */
 130         if (my_args.rcfile)
 131                 rcfile = (char *)my_args.rcfile;
 132         else {
 133                 int rc;
 134
 135                 rc = asprintf(&rcfile, LXCPATH "/%s/config", my_args.name);
 136                 if (rc == -1) {
 137                         SYSERROR("failed to allocate memory");
 138                         return -1;
 139                 }
 140
 141                 /* container configuration does not exist */
 142                 if (access(rcfile, F_OK)) {
 143                         free(rcfile);
 144                         rcfile = NULL;
 145                 }
 146         }
 147
 148         conf = lxc_conf_init();
 149         if (!conf) {
 150                 ERROR("failed to initialize configuration");
 151                 return -1;
 152         }
 153
 154         if (rcfile && lxc_config_read(rcfile, conf)) {
 155                 ERROR("failed to read configuration file");
 156                 return -1;
 157         }
 158
 159         if (lxc_config_define_load(&defines, conf))
 160                 return -1;
 161
 162         if (my_args.statefd != -1)
 163                 sfd = my_args.statefd;
 164
 165 #define OPEN_READ_MODE O_RDONLY | O_CLOEXEC | O_LARGEFILE
 166         if (my_args.statefile) {
 167                 sfd = open(my_args.statefile, OPEN_READ_MODE, 0);
 168                 if (sfd < 0) {
 169                         ERROR("'%s' open failure : %m", my_args.statefile);
 170                         return sfd;
 171                 }
 172         }
 173
 174         ret = lxc_restart(my_args.name, sfd, conf, my_args.flags);
 175
 176         if (my_args.statefile)
 177                 close(sfd);
 178         return ret;
 179 }