src/lxc/tools/lxc_execute.c

   1 /*
   2  * lxc: linux Container library
   3  *
   4  * (C) Copyright IBM Corp. 2007, 2008
   5  *
   6  * Authors:
   7  * Daniel Lezcano <daniel.lezcano at free.fr>
   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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  22  */
  23
  24 #ifndef _GNU_SOURCE
  25 #define _GNU_SOURCE 1
  26 #endif
  27 #include <errno.h>
  28 #include <libgen.h>
  29 #include <stdio.h>
  30 #include <stdlib.h>
  31 #include <string.h>
  32 #include <sys/param.h>
  33 #include <sys/stat.h>
  34 #include <sys/types.h>
  35 #include <sys/wait.h>
  36 #include <unistd.h>
  37
  38 #include <lxc/lxccontainer.h>
  39
  40 #include "arguments.h"
  41 #include "caps.h"
  42 #include "config.h"
  43 #include "confile.h"
  44 #include "log.h"
  45 #include "utils.h"
  46
  47 lxc_log_define(lxc_execute, lxc);
  48
  49 static int my_parser(struct lxc_arguments *args, int c, char *arg);
  50 static bool set_argv(struct lxc_container *c, struct lxc_arguments *args);
  51
  52 static struct lxc_list defines;
  53
  54 static const struct option my_longopts[] = {
  55         {"daemon", no_argument, 0, 'd'},
  56         {"rcfile", required_argument, 0, 'f'},
  57         {"define", required_argument, 0, 's'},
  58         {"uid", required_argument, 0, 'u'},
  59         {"gid", required_argument, 0, 'g'},
  60         {"share-net", required_argument, 0, OPT_SHARE_NET},
  61         {"share-ipc", required_argument, 0, OPT_SHARE_IPC},
  62         {"share-uts", required_argument, 0, OPT_SHARE_UTS},
  63         {"share-pid", required_argument, 0, OPT_SHARE_PID},
  64         LXC_COMMON_OPTIONS
  65 };
  66
  67 static struct lxc_arguments my_args = {
  68         .progname     = "lxc-execute",
  69         .help         = "\
  70 --name=NAME -- COMMAND\n\
  71 \n\
  72 lxc-execute creates a container with the identifier NAME\n\
  73 and execs COMMAND into this container.\n\
  74 \n\
  75 Options :\n\
  76   -n, --name=NAME      NAME of the container\n\
  77   -d, --daemon         Daemonize the container\n\
  78   -f, --rcfile=FILE    Load configuration file FILE\n\
  79   -s, --define KEY=VAL Assign VAL to configuration variable KEY\n\
  80   -u, --uid=UID        Execute COMMAND with UID inside the container\n\
  81   -g, --gid=GID        Execute COMMAND with GID inside the container\n",
  82         .options      = my_longopts,
  83         .parser       = my_parser,
  84         .log_priority = "ERROR",
  85         .log_file     = "none",
  86         .daemonize    = 0,
  87 };
  88
  89 static int my_parser(struct lxc_arguments *args, int c, char *arg)
  90 {
  91         int ret;
  92
  93         switch (c) {
  94         case 'd':
  95                 args->daemonize = 1;
  96                 break;
  97         case 'f':
  98                 args->rcfile = arg;
  99                 break;
 100         case 's':
 101                 ret = lxc_config_define_add(&defines, arg);
 102                 if (ret < 0)
 103                         lxc_config_define_free(&defines);
 104                 break;
 105         case 'u':
 106                 if (lxc_safe_uint(arg, &args->uid) < 0)
 107                         return -1;
 108                 break;
 109         case 'g':
 110                 if (lxc_safe_uint(arg, &args->gid) < 0)
 111                         return -1;
 112                 break;
 113         case OPT_SHARE_NET:
 114                 args->share_ns[LXC_NS_NET] = arg;
 115                 break;
 116         case OPT_SHARE_IPC:
 117                 args->share_ns[LXC_NS_IPC] = arg;
 118                 break;
 119         case OPT_SHARE_UTS:
 120                 args->share_ns[LXC_NS_UTS] = arg;
 121                 break;
 122         case OPT_SHARE_PID:
 123                 args->share_ns[LXC_NS_PID] = arg;
 124                 break;
 125         }
 126         return 0;
 127 }
 128
 129 static bool set_argv(struct lxc_container *c, struct lxc_arguments *args)
 130 {
 131         int ret;
 132         char buf[MAXPATHLEN];
 133         char **components, **p;
 134
 135         buf[0] = '\0';
 136         ret = c->get_config_item(c, "lxc.execute.cmd", buf, MAXPATHLEN);
 137         if (ret < 0)
 138                 return false;
 139
 140         components = lxc_string_split_quoted(buf);
 141         if (!components)
 142                 return false;
 143
 144         args->argv = components;
 145
 146         for (p = components; *p; p++)
 147                 args->argc++;
 148
 149         return true;
 150 }
 151
 152 int main(int argc, char *argv[])
 153 {
 154         struct lxc_container *c;
 155         struct lxc_log log;
 156         int err = EXIT_FAILURE;
 157         int ret;
 158         bool bret;
 159
 160         lxc_list_init(&defines);
 161
 162         if (lxc_caps_init())
 163                 exit(err);
 164
 165         if (lxc_arguments_parse(&my_args, argc, argv))
 166                 exit(err);
 167
 168         log.name = my_args.name;
 169         log.file = my_args.log_file;
 170         log.level = my_args.log_priority;
 171         log.prefix = my_args.progname;
 172         log.quiet = my_args.quiet;
 173         log.lxcpath = my_args.lxcpath[0];
 174
 175         if (lxc_log_init(&log))
 176                 exit(err);
 177
 178         c = lxc_container_new(my_args.name, my_args.lxcpath[0]);
 179         if (!c) {
 180                 ERROR("Failed to create lxc_container");
 181                 exit(err);
 182         }
 183
 184         if (my_args.rcfile) {
 185                 c->clear_config(c);
 186
 187                 if (!c->load_config(c, my_args.rcfile)) {
 188                         ERROR("Failed to load rcfile");
 189                         goto out;
 190                 }
 191
 192                 c->configfile = strdup(my_args.rcfile);
 193                 if (!c->configfile) {
 194                         ERROR("Out of memory setting new config filename");
 195                         goto out;
 196                 }
 197         }
 198
 199         if (!c->lxc_conf) {
 200                 ERROR("Executing a container with no configuration file may crash the host");
 201                 goto out;
 202         }
 203
 204         if (my_args.argc == 0)
 205                 if (!set_argv(c, &my_args)) {
 206                         ERROR("Missing command to execute!");
 207                         goto out;
 208                 }
 209
 210         bret = lxc_config_define_load(&defines, c);
 211         if (!bret)
 212                 goto out;
 213
 214         if (my_args.uid) {
 215                 char buf[256];
 216
 217                 ret = snprintf(buf, 256, "%d", my_args.uid);
 218                 if (ret < 0 || (size_t)ret >= 256)
 219                         goto out;
 220
 221                 bret = c->set_config_item(c, "lxc.init.uid", buf);
 222                 if (!bret)
 223                         goto out;
 224         }
 225
 226         if (my_args.gid) {
 227                 char buf[256];
 228
 229                 ret = snprintf(buf, 256, "%d", my_args.gid);
 230                 if (ret < 0 || (size_t)ret >= 256)
 231                         goto out;
 232
 233                 bret = c->set_config_item(c, "lxc.init.gid", buf);
 234                 if (!bret)
 235                         goto out;
 236         }
 237
 238         if (!lxc_setup_shared_ns(&my_args, c))
 239                 goto out;
 240
 241         c->daemonize = my_args.daemonize == 1;
 242
 243         bret = c->start(c, 1, my_args.argv);
 244         if (!bret) {
 245                 ERROR("Failed run an application inside container");
 246                 goto out;
 247         }
 248
 249         if (c->daemonize) {
 250                 err = EXIT_SUCCESS;
 251         } else {
 252                 if (WIFEXITED(c->error_num))
 253                         err = WEXITSTATUS(c->error_num);
 254                 else
 255                         /* Try to die with the same signal the task did. */
 256                         kill(0, WTERMSIG(c->error_num));
 257         }
 258
 259 out:
 260         lxc_container_put(c);
 261         exit(err);
 262 }