src/lxc/lxc.h

   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 #ifndef __lxc_h
  24 #define __lxc_h
  25
  26 #ifdef __cplusplus
  27 extern "C" {
  28 #endif
  29
  30 #include <stddef.h>
  31 #include <lxc/state.h>
  32
  33 struct lxc_msg;
  34
  35 /**
  36  Following code is for liblxc.
  37
  38  lxc/lxc.h will contain exports of liblxc
  39  **/
  40
  41 /*
  42  * Start the specified command inside a container
  43  * @name     : the name of the container
  44  * @argv     : an array of char * corresponding to the commande line
  45  * Returns 0 on sucess, < 0 otherwise
  46  */
  47 extern int lxc_start(const char *name, char *const argv[], const char *rcfile);
  48
  49 /*
  50  * Stop the container previously started with lxc_start, all
  51  * the processes running inside this container will be killed.
  52  * @name : the name of the container
  53  * Returns 0 on success, < 0 otherwise
  54  */
  55 extern int lxc_stop(const char *name);
  56
  57 /*
  58  * Open the monitoring mechanism for a specific container
  59  * The function will return an fd corresponding to the events
  60  * Returns a file descriptor on success, < 0 otherwise
  61  */
  62 extern int lxc_monitor_open(void);
  63
  64 /*
  65  * Read the state of the container if this one has changed
  66  * The function will block until there is an event available
  67  * @fd : the file descriptor provided by lxc_monitor_open
  68  * @state : the variable which will be filled with the state
  69  * Returns 0 if the monitored container has exited, > 0 if
  70  * data was readen, < 0 otherwise
  71  */
  72 extern int lxc_monitor_read(int fd, struct lxc_msg *msg);
  73
  74 /*
  75  * Close the fd associated with the monitoring
  76  * @fd : the file descriptor provided by lxc_monitor_open
  77  * Returns 0 on success, < 0 otherwise
  78  */
  79 extern int lxc_monitor_close(int fd);
  80
  81 /*
  82  * Show the console of the container.
  83  * @name : the name of container
  84  * @tty  : the tty number
  85  * @fd   : a pointer to a tty file descriptor
  86  * Returns 0 on sucess, < 0 otherwise
  87  */
  88 extern int lxc_console(const char *name, int ttynum, int *fd);
  89
  90 /*
  91  * Freeze all the tasks running inside the container <name>
  92  * @name : the container name
  93  * Returns 0 on success, < 0 otherwise
  94  */
  95 extern int lxc_freeze(const char *name);
  96
  97 /*
  98  * Unfreeze all previously frozen tasks.
  99  * @name : the name of the container
 100  * Return 0 on sucess, < 0 otherwise
 101  */
 102 extern int lxc_unfreeze(const char *name);
 103
 104 /*
 105  * Retrieve the container state
 106  * @name : the name of the container
 107  * Returns the state of the container on success, < 0 otherwise
 108  */
 109 extern lxc_state_t lxc_state(const char *name);
 110
 111 /*
 112  * Set a specified value for a specified subsystem. The specified
 113  * subsystem must be fully specified, eg. "cpu.shares"
 114  * @name      : the name of the container
 115  * @subsystem : the subsystem
 116  * @value     : the value to be set
 117  * Returns 0 on success, < 0 otherwise
 118  */
 119 extern int lxc_cgroup_set(const char *name, const char *subsystem, const char *value);
 120
 121 /*
 122  * Get a specified value for a specified subsystem. The specified
 123  * subsystem must be fully specified, eg. "cpu.shares"
 124  * @name      : the name of the container
 125  * @subsystem : the subsystem
 126  * @value     : the value to be set
 127  * @len       : the len of the value variable
 128  * Returns the number of bytes read, < 0 on error
 129  */
 130 extern int lxc_cgroup_get(const char *name, const char *subsystem,
 131                           char *value, size_t len);
 132
 133 /*
 134  * Retrieve the error string associated with the error returned by
 135  * the function.
 136  * @error : the value of the error
 137  * Returns a string on success or NULL otherwise.
 138  */
 139 extern const char *lxc_strerror(int error);
 140
 141 /*
 142  * Checkpoint a container
 143  * @name : the name of the container being checkpointed
 144  * @statefile: string object on which the container is checkpointed
 145  * @flags : checkpoint flags (an ORed value)
 146  * Returns 0 on success, < 0 otherwise
 147  */
 148 extern int lxc_checkpoint(const char *name, const char *statefile, int flags);
 149 #define LXC_FLAG_PAUSE 1
 150 #define LXC_FLAG_HALT  2
 151
 152 /*
 153  * Restart a container
 154  * @name : the name of the container being restarted
 155  * @statefile: string object from which the container is restarted
 156  * @rcfile: container configuration file.
 157  * @flags : restart flags (an ORed value)
 158  * Returns 0 on success, < 0 otherwise
 159  */
 160 extern int lxc_restart(const char *, const char *, const char *, int);
 161
 162 /*
 163  * Returns the version number of the library
 164  */
 165 extern const char const *lxc_version(void);
 166
 167 #ifdef __cplusplus
 168 }
 169 #endif
 170
 171 #endif