lxc/tools/lxc_execute.c

/*
 * lxc: linux Container library
 *
 * (C) Copyright IBM Corp. 2007, 2008
 *
 * Authors:
 * Daniel Lezcano <daniel.lezcano at free.fr>
 *
 * 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 */
#define _GNU_SOURCE
#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
#include <libgen.h>
#include <string.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/param.h>

#include "caps.h"
#include "lxc.h"
#include "log.h"
#include "conf.h"
#include "confile.h"
#include "arguments.h"
#include "config.h"
#include "start.h"
#include "utils.h"

lxc_log_define(lxc_execute_ui, lxc);

static struct lxc_list defines;

static int my_checker(const struct lxc_arguments* args)
{
    if (!args->argc) {
        lxc_error(args, "missing command to execute !");
        return -1;
    }

    return 0;
}

static int my_parser(struct lxc_arguments* args, int c, char* arg)
{
    switch (c) {
    case 'f':
        args->rcfile = arg;
        break;
    case 's':
        return lxc_config_define_add(&defines, arg);
        break;
    case 'u':
        if (lxc_safe_uint(arg, &args->uid) < 0)
            return -1;
        break;
    case 'g':
        if (lxc_safe_uint(arg, &args->gid) < 0)
            return -1;
    }
    return 0;
}

static const struct option my_longopts[] = {
    {"rcfile", required_argument, 0, 'f'},
    {"define", required_argument, 0, 's'},
    {"uid", required_argument, 0, 'u'},
    {"gid", required_argument, 0, 'g'},
    LXC_COMMON_OPTIONS
};

static struct lxc_arguments my_args = {
    .progname = "lxc-execute",
    .help     = "\
--name=NAME -- COMMAND\n\
\n\
lxc-execute creates a container with the identifier NAME\n\
and execs COMMAND into this container.\n\
\n\
Options :\n\
  -n, --name=NAME      NAME of the container\n\
  -f, --rcfile=FILE    Load configuration file FILE\n\
  -s, --define KEY=VAL Assign VAL to configuration variable KEY\n\
  -u, --uid=UID        Execute COMMAND with UID inside the container\n\
  -g, --gid=GID        Execute COMMAND with GID inside the container\n",
    .options  = my_longopts,
    .parser   = my_parser,
    .checker  = my_checker,
};

int main(int argc, char *argv[])
{
    char *rcfile;
    struct lxc_conf *conf;
    int ret;

    lxc_list_init(&defines);

    if (lxc_caps_init())
        exit(EXIT_FAILURE);

    if (lxc_arguments_parse(&my_args, argc, argv))
        exit(EXIT_FAILURE);

    if (lxc_log_init(my_args.name, my_args.log_file, my_args.log_priority,
             my_args.progname, my_args.quiet, my_args.lxcpath[0]))
        exit(EXIT_FAILURE);
    lxc_log_options_no_override();

    /* rcfile is specified in the cli option */
    if (my_args.rcfile)
        rcfile = (char *)my_args.rcfile;
    else {
        int rc;

        rc = asprintf(&rcfile, "%s/%s/config", my_args.lxcpath[0], my_args.name);
        if (rc == -1) {
            SYSERROR("failed to allocate memory");
            exit(EXIT_FAILURE);
        }

        /* 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");
        exit(EXIT_FAILURE);
    }

    if (rcfile && lxc_config_read(rcfile, conf, NULL)) {
        ERROR("failed to read configuration file");
        exit(EXIT_FAILURE);
    }

    if (lxc_config_define_load(&defines, conf))
        exit(EXIT_FAILURE);

    if (my_args.uid)
        conf->init_uid = my_args.uid;

    if (my_args.gid)
        conf->init_gid = my_args.gid;

    ret = lxc_execute(my_args.name, my_args.argv, my_args.quiet, conf, my_args.lxcpath[0], false);

    lxc_conf_free(conf);

    if (ret < 0)
        exit(EXIT_FAILURE);
    exit(ret);
}