src/lxc/lxc_start.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 #define _GNU_SOURCE
  24 #include <stdio.h>
  25 #undef _GNU_SOURCE
  26 #include <libgen.h>
  27 #include <stdlib.h>
  28 #include <unistd.h>
  29 #include <string.h>
  30 #include <termios.h>
  31 #include <errno.h>
  32 #include <fcntl.h>
  33 #include <signal.h>
  34 #include <sys/param.h>
  35 #include <sys/utsname.h>
  36 #include <sys/types.h>
  37 #include <sys/socket.h>
  38 #include <sys/stat.h>
  39 #include <arpa/inet.h>
  40 #include <netinet/in.h>
  41 #include <net/if.h>
  42
  43 #include "log.h"
  44 #include "caps.h"
  45 #include "lxc.h"
  46 #include <lxc/lxccontainer.h>
  47 #include "conf.h"
  48 #include "cgroup.h"
  49 #include "utils.h"
  50 #include "config.h"
  51 #include "confile.h"
  52 #include "arguments.h"
  53
  54 lxc_log_define(lxc_start_ui, lxc_start);
  55
  56 static struct lxc_list defines;
  57
  58 static int ensure_path(char **confpath, const char *path)
  59 {
  60         int err = -1, fd;
  61         char *fullpath = NULL;
  62
  63         if (path) {
  64                 if (access(path, W_OK)) {
  65                         fd = creat(path, 0600);
  66                         if (fd < 0 && errno != EEXIST) {
  67                                 SYSERROR("failed to create '%s'", path);
  68                                 goto err;
  69                         }
  70                         if (fd >= 0)
  71                                 close(fd);
  72                 }
  73
  74                 fullpath = realpath(path, NULL);
  75                 if (!fullpath) {
  76                         SYSERROR("failed to get the real path of '%s'", path);
  77                         goto err;
  78                 }
  79
  80                 *confpath = strdup(fullpath);
  81                 if (!*confpath) {
  82                         ERROR("failed to dup string '%s'", fullpath);
  83                         goto err;
  84                 }
  85         }
  86         err = 0;
  87
  88 err:
  89         if (fullpath)
  90                 free(fullpath);
  91         return err;
  92 }
  93
  94 static int my_parser(struct lxc_arguments* args, int c, char* arg)
  95 {
  96         switch (c) {
  97         case 'c': args->console = arg; break;
  98         case 'L': args->console_log = arg; break;
  99         case 'd': args->daemonize = 1; args->close_all_fds = 1; break;
 100         case 'f': args->rcfile = arg; break;
 101         case 'C': args->close_all_fds = 1; break;
 102         case 's': return lxc_config_define_add(&defines, arg);
 103         case 'p': args->pidfile = arg; break;
 104         }
 105         return 0;
 106 }
 107
 108 static const struct option my_longopts[] = {
 109         {"daemon", no_argument, 0, 'd'},
 110         {"rcfile", required_argument, 0, 'f'},
 111         {"define", required_argument, 0, 's'},
 112         {"console", required_argument, 0, 'c'},
 113         {"console-log", required_argument, 0, 'L'},
 114         {"close-all-fds", no_argument, 0, 'C'},
 115         {"pidfile", required_argument, 0, 'p'},
 116         LXC_COMMON_OPTIONS
 117 };
 118
 119 static struct lxc_arguments my_args = {
 120         .progname = "lxc-start",
 121         .help     = "\
 122 --name=NAME -- COMMAND\n\
 123 \n\
 124 lxc-start start COMMAND in specified container NAME\n\
 125 \n\
 126 Options :\n\
 127   -n, --name=NAME        NAME for name of the container\n\
 128   -d, --daemon           daemonize the container\n\
 129   -p, --pidfile=FILE     Create a file with the process id\n\
 130   -f, --rcfile=FILE      Load configuration file FILE\n\
 131   -c, --console=FILE     Use specified FILE for the container console\n\
 132   -L, --console-log=FILE Log container console output to FILE\n\
 133   -C, --close-all-fds    If any fds are inherited, close them\n\
 134                          If not specified, exit with failure instead\n\
 135                          Note: --daemon implies --close-all-fds\n\
 136   -s, --define KEY=VAL   Assign VAL to configuration variable KEY\n",
 137         .options   = my_longopts,
 138         .parser    = my_parser,
 139         .checker   = NULL,
 140         .daemonize = 0,
 141         .pidfile = NULL,
 142 };
 143
 144 int main(int argc, char *argv[])
 145 {
 146         int err = -1;
 147         struct lxc_conf *conf;
 148         char *const *args;
 149         char *rcfile = NULL;
 150         char *const default_args[] = {
 151                 "/sbin/init",
 152                 '\0',
 153         };
 154         FILE *pid_fp = NULL;
 155         struct lxc_container *c;
 156
 157         lxc_list_init(&defines);
 158
 159         if (lxc_caps_init())
 160                 return err;
 161
 162         if (lxc_arguments_parse(&my_args, argc, argv))
 163                 return err;
 164
 165         if (!my_args.argc)
 166                 args = default_args;
 167         else
 168                 args = my_args.argv;
 169
 170         if (lxc_log_init(my_args.name, my_args.log_file, my_args.log_priority,
 171                          my_args.progname, my_args.quiet, my_args.lxcpath[0]))
 172                 return err;
 173
 174         const char *lxcpath = my_args.lxcpath[0];
 175
 176         /*
 177          * rcfile possibilities:
 178          * 1. rcfile from random path specified in cli option
 179          * 2. rcfile not specified, use $lxcpath/$lxcname/config
 180          * 3. rcfile not specified and does not exist.
 181          */
 182         /* rcfile is specified in the cli option */
 183         if (my_args.rcfile) {
 184                 rcfile = (char *)my_args.rcfile;
 185                 c = lxc_container_new(my_args.name, lxcpath);
 186                 if (!c) {
 187                         ERROR("Failed to create lxc_container");
 188                         return err;
 189                 }
 190                 if (!c->load_config(c, rcfile)) {
 191                         ERROR("Failed to load rcfile");
 192                         lxc_container_put(c);
 193                         return err;
 194                 }
 195         } else {
 196                 int rc;
 197
 198                 rc = asprintf(&rcfile, "%s/%s/config", lxcpath, my_args.name);
 199                 if (rc == -1) {
 200                         SYSERROR("failed to allocate memory");
 201                         return err;
 202                 }
 203                 INFO("using rcfile %s", rcfile);
 204
 205                 /* container configuration does not exist */
 206                 if (access(rcfile, F_OK)) {
 207                         free(rcfile);
 208                         rcfile = NULL;
 209                 }
 210                 c = lxc_container_new(my_args.name, lxcpath);
 211                 if (!c) {
 212                         ERROR("Failed to create lxc_container");
 213                         return err;
 214                 }
 215         }
 216
 217         /*
 218          * We should use set_config_item() over &defines, which would handle
 219          * unset c->lxc_conf for us and let us not use lxc_config_define_load()
 220          */
 221         if (!c->lxc_conf)
 222                 c->lxc_conf = lxc_conf_init();
 223         conf = c->lxc_conf;
 224
 225         if (lxc_config_define_load(&defines, conf))
 226                 goto out;
 227
 228         if (!rcfile && !strcmp("/sbin/init", args[0])) {
 229                 ERROR("Executing '/sbin/init' with no configuration file may crash the host");
 230                 goto out;
 231         }
 232
 233         if (ensure_path(&conf->console.path, my_args.console) < 0) {
 234                 ERROR("failed to ensure console path '%s'", my_args.console);
 235                 goto out;
 236         }
 237
 238         if (ensure_path(&conf->console.log_path, my_args.console_log) < 0) {
 239                 ERROR("failed to ensure console log '%s'", my_args.console_log);
 240                 goto out;
 241         }
 242
 243         if (my_args.pidfile != NULL) {
 244                 pid_fp = fopen(my_args.pidfile, "w");
 245                 if (pid_fp == NULL) {
 246                         SYSERROR("failed to create pidfile '%s' for '%s'",
 247                                  my_args.pidfile, my_args.name);
 248                         goto out;
 249                 }
 250         }
 251
 252         if (my_args.daemonize) {
 253                 c->want_daemonize(c);
 254         }
 255
 256         if (pid_fp != NULL) {
 257                 if (fprintf(pid_fp, "%d\n", getpid()) < 0) {
 258                         SYSERROR("failed to write '%s'", my_args.pidfile);
 259                         goto out;
 260                 }
 261                 fclose(pid_fp);
 262         }
 263
 264         if (my_args.close_all_fds)
 265                 c->want_close_all_fds(c);
 266
 267         err = c->start(c, 0, args) ? 0 : -1;
 268
 269         if (my_args.pidfile)
 270                 unlink(my_args.pidfile);
 271
 272 out:
 273         lxc_container_put(c);
 274         return err;
 275 }
 276