1 # Copyright 2005 Princeton University
3 #$Id: vserver.py,v 1.72 2007/08/02 16:01:59 dhozac Exp $
18 import cpulimit, bwlimit
20 from vserverimpl import DLIMIT_INF
21 from vserverimpl import VC_LIM_KEEP
22 from vserverimpl import VLIMIT_NSOCK
23 from vserverimpl import VLIMIT_OPENFD
24 from vserverimpl import VLIMIT_ANON
25 from vserverimpl import VLIMIT_SHMEM
28 # these are the flags taken from the kernel linux/vserver/legacy.h
31 FLAGS_SCHED = 2 # XXX - defined in util-vserver/src/chcontext.c
39 RLIMITS = { "NSOCK": VLIMIT_NSOCK,
40 "OPENFD": VLIMIT_OPENFD,
42 "SHMEM": VLIMIT_SHMEM}
44 # add in the platform supported rlimits
45 for entry in resource.__dict__.keys():
46 if entry.find("RLIMIT_")==0:
47 k = entry[len("RLIMIT_"):]
48 if not RLIMITS.has_key(k):
49 RLIMITS[k]=resource.__dict__[entry]
51 print "WARNING: duplicate RLIMITS key %s" % k
53 class NoSuchVServer(Exception): pass
57 def __init__(self, name, directory):
61 if not (os.path.isdir(self.dir) and
62 os.access(self.dir, os.R_OK | os.W_OK | os.X_OK)):
63 raise NoSuchVServer, "%s does not exist" % self.dir
65 def get(self, option, default = None):
68 return self.cache[option]
70 f = open(os.path.join(self.dir, option), "r")
71 buf = f.read().rstrip()
75 if default is not None:
78 raise KeyError, "Key %s is not set for %s" % (option, self.name)
80 def update(self, option, value):
85 old_umask = os.umask(0022)
86 filename = os.path.join(self.dir, option)
88 os.makedirs(os.path.dirname(filename), 0755)
91 f = open(filename, 'w')
92 if isinstance(value, list):
93 f.write("%s\n" % "\n".join(value))
95 f.write("%s\n" % value)
101 def unset(self, option):
106 filename = os.path.join(self.dir, option)
109 os.removedirs(os.path.dirname(filename))
118 def add_to_cache(cache, dirname, fnames):
120 full_name = os.path.join(dirname, file)
121 if os.path.islink(full_name):
123 elif (os.path.isfile(full_name) and
124 os.access(full_name, os.R_OK)):
125 f = open(full_name, "r")
126 cache[full_name.replace(os.path.join(self.dir, ''),
127 '')] = f.read().rstrip()
129 os.path.walk(self.dir, add_to_cache, self.cache)
134 INITSCRIPTS = [('/etc/rc.vinit', 'start'),
135 ('/etc/rc.d/rc', '%(runlevel)d')]
137 def __init__(self, name, vm_id = None, vm_running = None, logfile=None):
140 self.rlimits_changed = False
141 self.dir = "%s/%s" % (vserverimpl.VSERVER_BASEDIR, name)
142 if not (os.path.isdir(self.dir) and
143 os.access(self.dir, os.R_OK | os.W_OK | os.X_OK)):
144 raise NoSuchVServer, "no such vserver: " + name
145 self.config = VServerConfig(name, "/etc/vservers/%s" % name)
146 self.remove_caps = ~vserverimpl.CAP_SAFE;
148 vm_id = int(self.config.get('context'))
150 if vm_running == None:
151 vm_running = self.is_running()
152 self.vm_running = vm_running
153 self.logfile = logfile
155 # inspired from nodemanager's logger
159 fd = os.open(self.logfile,os.O_WRONLY | os.O_CREAT | os.O_APPEND, 0600)
160 if not msg.endswith('\n'): msg += '\n'
161 os.write(fd, '%s: %s' % (time.asctime(time.gmtime()), msg))
164 print '%s: (%s failed to open) %s'%(time.asctime(time.gmtime()),self.logfile,msg)
166 def have_limits_changed(self):
167 return self.rlimits_changed
169 def set_rlimit_limit(self,type,hard,soft,minimum):
170 """Generic set resource limit function for vserver"""
174 old_hard, old_soft, old_minimum = self.get_rlimit_limit(type)
175 if old_hard != VC_LIM_KEEP and old_hard <> hard: changed = True
176 if old_soft != VC_LIM_KEEP and old_soft <> soft: changed = True
177 if old_minimum != VC_LIM_KEEP and old_minimum <> minimum: changed = True
178 self.rlimits_changed = self.rlimits_changed or changed
180 if self.is_running(): self.log("Unexpected error with getrlimit for running context %d" % self.ctx)
182 resource_type = RLIMITS[type]
184 ret = vserverimpl.setrlimit(self.ctx,resource_type,hard,soft,minimum)
186 if self.is_running(): self.log("Unexpected error with setrlimit for running context %d" % self.ctx)
188 def set_rlimit_config(self,type,hard,soft,minimum):
189 """Generic set resource limit function for vserver"""
190 if hard <> VC_LIM_KEEP:
191 self.config.update('rlimits/%s.hard' % type.lower(), hard)
192 if soft <> VC_LIM_KEEP:
193 self.config.update('rlimits/%s.soft' % type.lower(), soft)
194 if minimum <> VC_LIM_KEEP:
195 self.config.update('rlimits/%s.min' % type.lower(), minimum)
196 self.set_rlimit_limit(type,hard,soft,minimum)
198 def get_rlimit_limit(self,type):
199 """Generic get resource configuration function for vserver"""
201 resource_type = RLIMITS[type]
203 ret = vserverimpl.getrlimit(self.ctx,resource_type)
205 self.log("Unexpected error with getrlimit for context %d" % self.ctx)
206 ret = self.get_rlimit_config(type)
209 def get_rlimit_config(self,type):
210 """Generic get resource configuration function for vserver"""
211 hard = int(self.config.get("rlimits/%s.hard"%type.lower(),VC_LIM_KEEP))
212 soft = int(self.config.get("rlimits/%s.soft"%type.lower(),VC_LIM_KEEP))
213 minimum = int(self.config.get("rlimits/%s.min"%type.lower(),VC_LIM_KEEP))
214 return (hard,soft,minimum)
216 def set_capabilities(self, capabilities):
217 return vserverimpl.setbcaps(self.ctx, vserverimpl.text2bcaps(capabilities))
219 def set_capabilities_config(self, capabilities):
220 self.config.update('bcapabilities', capabilities)
221 self.set_capabilities(capabilities)
223 def get_capabilities(self):
224 return vserverimpl.bcaps2text(vserverimpl.getbcaps(self.ctx))
226 def get_capabilities_config(self):
227 return self.config.get('bcapabilities', '')
229 def set_ipaddresses(self, addresses):
230 vserverimpl.netremove(self.ctx, "all")
231 for a in addresses.split(","):
232 vserverimpl.netadd(self.ctx, a)
234 def set_ipaddresses_config(self, addresses):
236 for a in addresses.split(","):
237 self.config.update("interfaces/%d/ip" % i, a)
239 while self.config.unset("interfaces/%d/ip" % i):
241 self.set_ipaddresses(addresses)
243 def get_ipaddresses_config(self):
247 r = self.config.get("interfaces/%d/ip" % i, '')
254 def get_ipaddresses(self):
255 # No clean way to do this right now.
258 def __do_chroot(self):
262 def chroot_call(self, fn, *args):
264 cwd_fd = os.open(".", os.O_RDONLY)
266 root_fd = os.open("/", os.O_RDONLY)
279 def set_disklimit(self, block_limit):
280 # block_limit is in kB
283 vserverimpl.unsetdlimit(self.dir, self.ctx)
285 self.log("Unexpected error with unsetdlimit for context %d" % self.ctx)
289 block_usage = vserverimpl.DLIMIT_KEEP
290 inode_usage = vserverimpl.DLIMIT_KEEP
292 # init_disk_info() must have been called to get usage values
293 block_usage = self.disk_blocks
294 inode_usage = self.disk_inodes
298 vserverimpl.setdlimit(self.dir,
303 vserverimpl.DLIMIT_INF, # inode limit
304 2) # %age reserved for root
306 self.log("Unexpected error with setdlimit for context %d" % self.ctx)
309 self.config.update('dlimits/0/space_total', block_limit)
311 def is_running(self):
312 return vserverimpl.isrunning(self.ctx)
314 def get_disklimit(self):
317 (self.disk_blocks, block_limit, self.disk_inodes, inode_limit,
318 reserved) = vserverimpl.getdlimit(self.dir, self.ctx)
320 if ex.errno != errno.ESRCH:
322 # get here if no vserver disk limit has been set for xid
327 def set_sched_config(self, cpu_min, cpu_share):
329 """ Write current CPU scheduler parameters to the vserver
330 configuration file. This method does not modify the kernel CPU
331 scheduling parameters for this context. """
333 self.config.update('sched/fill-rate', cpu_min)
334 self.config.update('sched/fill-rate2', cpu_share)
336 self.config.unset('sched/idle-time')
338 if self.is_running():
339 self.set_sched(cpu_min, cpu_share)
341 def set_sched(self, cpu_min, cpu_share):
342 """ Update kernel CPU scheduling parameters for this context. """
343 vserverimpl.setsched(self.ctx, cpu_min, cpu_share)
346 # have no way of querying scheduler right now on a per vserver basis
349 def set_bwlimit(self, minrate = bwlimit.bwmin, maxrate = None,
350 exempt_min = None, exempt_max = None,
351 share = None, dev = "eth0"):
354 bwlimit.off(self.ctx, dev)
356 bwlimit.on(self.ctx, dev, share,
357 minrate, maxrate, exempt_min, exempt_max)
359 def get_bwlimit(self, dev = "eth0"):
361 result = bwlimit.get(self.ctx)
362 # result of bwlimit.get is (ctx, share, minrate, maxrate)
367 def open(self, filename, mode = "r", bufsize = -1):
369 return self.chroot_call(open, filename, mode, bufsize)
371 def __do_chcontext(self, state_file):
374 print >>state_file, "%u" % self.ctx
377 if vserverimpl.chcontext(self.ctx, vserverimpl.text2bcaps(self.get_capabilities_config())):
379 vserverimpl.setup_done(self.ctx)
381 def __prep(self, runlevel):
383 """ Perform all the crap that the vserver script does before
384 actually executing the startup scripts. """
386 # remove /var/run and /var/lock/subsys files
387 # but don't remove utmp from the top-level /var/run
389 LOCKDIR = "/var/lock/subsys"
390 filter_fn = lambda fs: filter(lambda f: f != 'utmp', fs)
391 garbage = reduce((lambda (out, ff), (dir, subdirs, files):
392 (out + map((dir + "/").__add__, ff(files)),
394 list(os.walk(RUNDIR)),
396 garbage += filter(os.path.isfile, map((LOCKDIR + "/").__add__,
397 os.listdir(LOCKDIR)))
402 # set the initial runlevel
403 vserverimpl.setrunlevel(RUNDIR + "/utmp", runlevel)
405 # mount /proc and /dev/pts
406 self.__do_mount("none", self.dir, "/proc", "proc")
407 # XXX - magic mount options
408 self.__do_mount("none", self.dir, "/dev/pts", "devpts", 0, "gid=5,mode=0620")
410 def __do_mount(self, *mount_args):
413 vserverimpl.mount(*mount_args)
415 if ex.errno == errno.EBUSY:
416 # assume already mounted
421 self.config.cache_it()
423 self.__do_chcontext(None)
425 def start(self, wait, runlevel = 3):
426 self.vm_running = True
427 self.rlimits_changed = False
429 child_pid = os.fork()
436 # open state file to record vserver info
437 state_file = open("/var/run/vservers/%s" % self.name, "w")
439 # use /dev/null for stdin, /var/log/boot.log for stdout/err
440 fd = os.open("/dev/null", os.O_RDONLY)
445 # perform pre-init cleanup
446 self.__prep(runlevel)
448 self.config.cache_it()
450 log = open("/var/log/boot.log", "a", 0)
451 if log.fileno() != 1:
452 os.dup2(log.fileno(), 1)
455 print >>log, ("%s: starting the virtual server %s" %
456 (time.asctime(time.gmtime()), self.name))
457 # execute each init script in turn
458 # XXX - we don't support all scripts that vserver script does
459 self.__do_chcontext(state_file)
460 for cmd in self.INITSCRIPTS:
462 # enter vserver context
463 arg_subst = { 'runlevel': runlevel }
464 cmd_args = [cmd[0]] + map(lambda x: x % arg_subst,
466 print >>log, "executing '%s'" % " ".join(cmd_args)
467 os.spawnvp(os.P_NOWAIT,cmd[0],cmd_args)
469 print >>log, traceback.format_exc()
472 # we get here due to an exception in the top-level child process
473 except Exception, ex:
474 self.log(traceback.format_exc())
480 def set_resources(self):
482 """ Called when vserver context is entered for first time,
483 should be overridden by subclass. """
487 def init_disk_info(self):
488 cmd = "/usr/sbin/vdu --script --space --inodes --blocksize 1024 --xid %d %s" % (self.ctx, self.dir)
489 p = subprocess.Popen(cmd, shell=True, stdin=subprocess.PIPE,
490 stdout=subprocess.PIPE, stderr=subprocess.PIPE,
493 line = p.stdout.readline()
495 sys.stderr.write(p.stderr.read())
500 (space, inodes) = line.split()
501 self.disk_inodes = int(inodes)
502 self.disk_blocks = int(space)
503 #(self.disk_inodes, self.disk_blocks) = vduimpl.vdu(self.dir)
505 return self.disk_blocks * 1024
507 def stop(self, signal = signal.SIGKILL):
508 vserverimpl.killall(self.ctx, signal)
509 self.vm_running = False
510 self.rlimits_changed = False
514 def create(vm_name, static = False, ctor = VServer):
516 options = ['vuseradd']
518 options += ['--static']
519 ret = os.spawnvp(os.P_WAIT, 'vuseradd', options + [vm_name])
520 if not os.WIFEXITED(ret) or os.WEXITSTATUS(ret) != 0:
521 out = "system command ('%s') " % options
522 if os.WIFEXITED(ret):
523 out += "failed, rc = %d" % os.WEXITSTATUS(ret)
525 out += "killed by signal %d" % os.WTERMSIG(ret)
526 raise SystemError, out
527 vm_id = pwd.getpwnam(vm_name)[2]
529 return ctor(vm_name, vm_id)