test/lxc_monitor.c

   1 /*
   2  * lxc: linux Container library
   3  *
   4  * (C) Copyright IBM Corp. 2007, 2008
   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 #include <stdio.h>
  24 #include <unistd.h>
  25 #include <string.h>
  26 #include <libgen.h>
  27
  28 #include <lxc.h>
  29
  30 void usage(char *cmd)
  31 {
  32         fprintf(stderr, "%s <command>\n", basename(cmd));
  33         fprintf(stderr, "\t -n <name>   : name of the container\n");
  34         _exit(1);
  35 }
  36
  37 int main(int argc, char *argv[])
  38 {
  39         char opt;
  40         char *name = NULL;
  41         int fds[2];
  42         pid_t pid;
  43
  44         while ((opt = getopt(argc, argv, "n:")) != -1) {
  45                 switch (opt) {
  46                 case 'n':
  47                         name = optarg;
  48                         break;
  49                 }
  50         }
  51
  52         if (!name)
  53                 usage(argv[0]);
  54
  55         if (pipe(fds)) {
  56                 perror("pipe");
  57                 return 1;
  58         }
  59
  60
  61
  62         pid = fork();
  63         if (pid < 0) {
  64                 perror("fork");
  65                 return 1;
  66         }
  67
  68         if (!pid) {
  69                 close(fds[0]);
  70                 if (lxc_monitor(name, fds[1])) {
  71                         fprintf(stderr, "failed to monitor %s\n", name);
  72                         return 1;
  73                 }
  74
  75                 return 0;
  76         }
  77
  78         close(fds[1]);
  79
  80         for (;;) {
  81                 int err, state;
  82
  83                 err = read(fds[0], &state, sizeof(state));
  84                 if (err < 0) {
  85                         perror("read");
  86                         return 1;
  87                 }
  88
  89                 if (!err) {
  90                         printf("container has been destroyed\n");
  91                         return 0;
  92                 }
  93
  94                 printf("container has changed the state to %d - %s\n",
  95                        state, state2str(state));
  96         }
  97
  98         return 0;
  99 }