1 # Copyright 2005 Princeton University
3 #$Id: vserver.py,v 1.72 2007/08/02 16:01:59 dhozac Exp $
19 import cpulimit, bwlimit
21 from vserverimpl import DLIMIT_INF
22 from vserverimpl import VC_LIM_KEEP
23 from vserverimpl import VLIMIT_NSOCK
24 from vserverimpl import VLIMIT_OPENFD
25 from vserverimpl import VLIMIT_ANON
26 from vserverimpl import VLIMIT_SHMEM
29 # these are the flags taken from the kernel linux/vserver/legacy.h
32 FLAGS_SCHED = 2 # XXX - defined in util-vserver/src/chcontext.c
40 RLIMITS = { "NSOCK": VLIMIT_NSOCK,
41 "OPENFD": VLIMIT_OPENFD,
43 "SHMEM": VLIMIT_SHMEM}
47 # add in the platform supported rlimits
48 for entry in resource.__dict__.keys():
49 if entry.find("RLIMIT_")==0:
50 k = entry[len("RLIMIT_"):]
51 if not RLIMITS.has_key(k):
52 RLIMITS[k]=resource.__dict__[entry]
54 print "WARNING: duplicate RLIMITS key %s" % k
56 class NoSuchVServer(Exception): pass
59 def __init__(self, name, directory):
63 if not (os.path.isdir(self.dir) and
64 os.access(self.dir, os.R_OK | os.W_OK | os.X_OK)):
65 raise NoSuchVServer, "%s does not exist" % self.dir
67 def get(self, option, default = None):
70 return self.cache[option]
72 f = open(os.path.join(self.dir, option), "r")
73 buf = f.read().rstrip()
77 if default is not None:
80 raise KeyError, "Key %s is not set for %s" % (option, self.name)
82 def update(self, option, value):
87 old_umask = os.umask(0022)
88 filename = os.path.join(self.dir, option)
90 os.makedirs(os.path.dirname(filename), 0755)
93 f = open(filename, 'w')
94 if isinstance(value, list):
95 f.write("%s\n" % "\n".join(value))
97 f.write("%s\n" % value)
103 def unset(self, option):
108 filename = os.path.join(self.dir, option)
111 os.removedirs(os.path.dirname(filename))
120 def add_to_cache(cache, dirname, fnames):
122 full_name = os.path.join(dirname, file)
123 if os.path.islink(full_name):
125 elif (os.path.isfile(full_name) and
126 os.access(full_name, os.R_OK)):
127 f = open(full_name, "r")
128 cache[full_name.replace(os.path.join(self.dir, ''),
129 '')] = f.read().rstrip()
131 os.path.walk(self.dir, add_to_cache, self.cache)
136 # adding the sliver name is for helping in the forensics
137 INITSCRIPTS = [('/etc/rc.vinit', 'start', '%(name)s'),
138 ('/etc/rc.d/rc', '%(runlevel)d')]
140 def __init__(self, name, vm_id = None, vm_running = None, logfile=None):
143 self.dir = "%s/%s" % (vserverimpl.VSERVER_BASEDIR, name)
144 if not (os.path.isdir(self.dir) and
145 os.access(self.dir, os.R_OK | os.W_OK | os.X_OK)):
146 raise NoSuchVServer, "no such vserver: " + name
147 self.config = VServerConfig(name, "/etc/vservers/%s" % name)
148 #self.remove_caps = ~vserverimpl.CAP_SAFE;
150 vm_id = int(self.config.get('context'))
152 if vm_running == None:
153 vm_running = self.is_running()
154 self.vm_running = vm_running
155 self.logfile = logfile
157 # inspired from nodemanager's logger
158 def log_in_file (self, fd, msg):
160 if not msg.endswith('\n'): msg += '\n'
161 os.write(fd, '%s: %s' % (time.asctime(time.gmtime()), msg))
166 fd = os.open(self.logfile,os.O_WRONLY | os.O_CREAT | os.O_APPEND, 0600)
167 self.log_in_file(fd,msg)
170 print '%s: (%s failed to open) %s'%(time.asctime(time.gmtime()),self.logfile,msg)
172 def set_rlimit(self, type, hard, soft, min):
173 """Generic set resource limit function for vserver"""
177 if hard <> VC_LIM_KEEP:
178 self.config.update('rlimits/%s.hard' % type.lower(), hard)
180 if soft <> VC_LIM_KEEP:
181 self.config.update('rlimits/%s.soft' % type.lower(), soft)
183 if min <> VC_LIM_KEEP:
184 self.config.update('rlimits/%s.min' % type.lower(), min)
187 if self.is_running() and update:
188 resource_type = RLIMITS[type]
190 vserverimpl.setrlimit(self.ctx, resource_type, hard, soft, min)
192 self.log("Error: setrlimit(%d, %s, %d, %d, %d): %s"
193 % (self.ctx, type.lower(), hard, soft, min, e))
197 def get_prefix_from_capabilities(self, capabilities, prefix):
198 split_caps = capabilities.split(',')
199 return ",".join(["%s" % (c) for c in split_caps if c.startswith(prefix.upper()) or c.startswith(prefix.lower())])
201 def get_bcaps_from_capabilities(self, capabilities):
202 return self.get_prefix_from_capabilities(capabilities, "cap_")
204 def get_ccaps_from_capabilities(self, capabilities):
205 return self.get_prefix_from_capabilities(capabilities, "vxc_")
207 def set_capabilities_config(self, capabilities):
208 bcaps = self.get_bcaps_from_capabilities(capabilities)
209 ccaps = self.get_ccaps_from_capabilities(capabilities)
212 bcaps += "CAP_NET_RAW"
213 self.config.update('bcapabilities', bcaps)
214 self.config.update('ccapabilities', ccaps)
215 ret = vserverimpl.setbcaps(self.ctx, vserverimpl.text2bcaps(bcaps))
218 return vserverimpl.setccaps(self.ctx, vserverimpl.text2ccaps(ccaps))
220 def get_capabilities(self):
221 bcaps = vserverimpl.bcaps2text(vserverimpl.getbcaps(self.ctx))
222 ccaps = vserverimpl.ccaps2text(vserverimpl.getccaps(self.ctx))
225 return (bcaps + ccaps)
227 def get_capabilities_config(self):
228 bcaps = self.config.get('bcapabilities', '')
229 ccaps = self.config.get('ccapabilities', '')
232 return (bcaps + ccaps)
234 def set_ipaddresses(self, addresses):
235 vserverimpl.netremove(self.ctx, "all")
236 for a in addresses.split(","):
237 vserverimpl.netadd(self.ctx, a)
239 def set_ipaddresses_config(self, addresses):
242 for a in addresses.split(","):
243 self.config.update("interfaces/%d/ip" % i, a)
245 while self.config.unset("interfaces/%d/ip" % i):
247 self.set_ipaddresses(addresses)
249 def get_ipaddresses_config(self):
253 r = self.config.get("interfaces/%d/ip" % i, '')
260 def get_ipaddresses(self):
261 # No clean way to do this right now.
262 self.log("Calling Vserver.get_ipaddresses for slice %s" % self.name)
265 def __do_chroot(self):
269 def chroot_call(self, fn, *args, **kwargs):
270 cwd_fd = os.open(".", os.O_RDONLY)
272 root_fd = os.open("/", os.O_RDONLY)
275 result = fn(*args, **kwargs)
285 def set_disklimit(self, block_limit):
286 # block_limit is in kB
289 vserverimpl.unsetdlimit(self.dir, self.ctx)
291 self.log("Unexpected error with unsetdlimit for context %d" % self.ctx)
295 block_usage = vserverimpl.DLIMIT_KEEP
296 inode_usage = vserverimpl.DLIMIT_KEEP
298 # init_disk_info() must have been called to get usage values
299 block_usage = self.disk_blocks
300 inode_usage = self.disk_inodes
303 vserverimpl.setdlimit(self.dir,
308 vserverimpl.DLIMIT_INF, # inode limit
309 2) # %age reserved for root
311 self.log("Unexpected error with setdlimit for context %d" % self.ctx)
313 self.config.update('dlimits/0/space_total', block_limit)
315 def is_running(self):
316 status = subprocess.call(["/usr/sbin/vserver", self.name, "running"], shell=False)
319 def get_disklimit(self):
321 (self.disk_blocks, block_limit, self.disk_inodes, inode_limit,
322 reserved) = vserverimpl.getdlimit(self.dir, self.ctx)
324 if ex.errno != errno.ESRCH:
326 # get here if no vserver disk limit has been set for xid
331 def set_sched_config(self, cpu_min, cpu_share):
332 """ Write current CPU scheduler parameters to the vserver
333 configuration file. Currently, 'cpu_min' is not supported. """
334 self.config.update('cgroup/cpu.shares', cpu_share * CPU_SHARE_MULT)
335 if self.is_running():
336 self.set_sched(cpu_min, cpu_share)
338 def set_sched(self, cpu_min, cpu_share):
339 """ Update kernel CPU scheduling parameters for this context.
340 Currently, 'cpu_min' is not supported. """
342 cgroup = open('/dev/cgroup/%s/cpu.shares' % name, 'w')
343 cgroup.write('%s' % (cpu_share * CPU_SHARE_MULT))
350 cpu_share = int(int(self.config.get('cgroup/cpu.shares')) / CPU_SHARE_MULT)
353 return (-1, cpu_share)
355 def set_bwlimit(self, minrate = bwlimit.bwmin, maxrate = None,
356 exempt_min = None, exempt_max = None,
357 share = None, dev = "eth0"):
360 bwlimit.off(self.ctx, dev)
362 bwlimit.on(self.ctx, dev, share,
363 minrate, maxrate, exempt_min, exempt_max)
365 def get_bwlimit(self, dev = "eth0"):
367 result = bwlimit.get(self.ctx)
368 # result of bwlimit.get is (ctx, share, minrate, maxrate)
373 def open(self, filename, mode = "r", bufsize = -1):
375 return self.chroot_call(open, filename, mode, bufsize)
378 subprocess.call("/usr/sbin/vserver %s enter" % self.name, shell=True)
380 # detach the process that triggers the initscripts
381 # after http://code.activestate.com/recipes/278731/
382 def start(self, runlevel = 3):
384 # Parent should just return.
385 self.vm_running = True
389 # first child process: fork again
391 os._exit(0) # Exit parent (the first child) of the second child.
392 # the grandson is the working one
397 subprocess.call(["/usr/sbin/vserver",self.name,"start"])
399 # execute initscripts
400 for cmd_to_expand in self.INITSCRIPTS:
401 # enter vserver context
402 expand = { 'runlevel': runlevel,
404 cmd = [ x % expand for x in cmd_to_expand ]
405 cmd_name = os.path.basename(cmd[0])
406 cmd_file = "/vservers/" + self.name + cmd[0]
407 if not os.path.isfile(cmd_file):
408 self.log("WARNING: could not find %s for %s" % (cmd_file, self.name))
410 self.log("executing %r" % cmd)
412 logname='/vservers/%s/var/log/%s'%(self.name,cmd_name)
413 log_fd=os.open(logname,os.O_WRONLY | os.O_CREAT | os.O_APPEND, 0600)
414 self.log_in_file(log_fd,"Running %r into %s"%(cmd,logname))
415 self.chroot_call(subprocess.call,cmd,
416 stdout=log_fd,stderr=subprocess.STDOUT,
418 except: self.log(traceback.format_exc())
419 finally: os.close(log_fd)
421 # we get here due to an exception in the grandson process
422 except Exception, ex:
423 self.log(traceback.format_exc())
426 def set_resources(self):
428 """ Called when vserver context is entered for first time,
429 should be overridden by subclass. """
433 def init_disk_info(self):
435 dlimit = vserverimpl.getdlimit(self.dir, self.ctx)
436 self.disk_blocks = dlimit[0]
437 self.disk_inodes = dlimit[2]
438 return self.disk_blocks * 1024
441 cmd = "/usr/sbin/vdu --script --space --inodes --blocksize 1024 --xid %d %s" % (self.ctx, self.dir)
442 p = subprocess.Popen(cmd, shell=True, stdin=subprocess.PIPE,
443 stdout=subprocess.PIPE, stderr=subprocess.PIPE,
446 line = p.stdout.readline()
448 sys.stderr.write(p.stderr.read())
453 (space, inodes) = line.split()
454 self.disk_inodes = int(inodes)
455 self.disk_blocks = int(space)
457 return self.disk_blocks * 1024
459 def stop(self, signal = signal.SIGKILL):
460 self.vm_running = False
461 subprocess.call("/usr/sbin/vserver %s stop" % self.name, shell=True)
463 def setname(self, slice_id):
467 '''Get vcVHI_CONTEXT field in kernel'''
468 return vserverimpl.getname(self.ctx)
471 def create(vm_name, static = False, ctor = VServer):
473 options = ['vuseradd']
475 options += ['--static']
476 ret = os.spawnvp(os.P_WAIT, 'vuseradd', options + [vm_name])
477 if not os.WIFEXITED(ret) or os.WEXITSTATUS(ret) != 0:
478 out = "system command ('%s') " % options
479 if os.WIFEXITED(ret):
480 out += "failed, rc = %d" % os.WEXITSTATUS(ret)
482 out += "killed by signal %d" % os.WTERMSIG(ret)
483 raise SystemError, out
484 vm_id = pwd.getpwnam(vm_name)[2]
486 return ctor(vm_name, vm_id)
489 def close_nonstandard_fds():
490 """Close all open file descriptors other than 0, 1, and 2."""
492 for fd in range(3, os.sysconf(_SC_OPEN_MAX)):
494 except OSError: pass # most likely an fd that isn't open