1 # Copyright 2005 Princeton University
16 import vserverimpl, vduimpl
17 import cpulimit, bwlimit
19 from vserverimpl import VS_SCHED_CPU_GUARANTEED as SCHED_CPU_GUARANTEED
24 # these are the flags taken from the kernel linux/vserver/legacy.h
27 FLAGS_SCHED = 2 # XXX - defined in util-vserver/src/chcontext.c
39 INITSCRIPTS = [('/etc/rc.vinit', 'start'),
40 ('/etc/rc.d/rc', '%(runlevel)d')]
42 def __init__(self, name, vm_id, vm_running = False):
45 self.config_file = "/etc/vservers/%s.conf" % name
46 self.dir = "%s/%s" % (vserverimpl.VSERVER_BASEDIR, name)
47 if not (os.path.isdir(self.dir) and
48 os.access(self.dir, os.R_OK | os.W_OK | os.X_OK)):
49 raise Exception, "no such vserver: " + name
51 for config_file in ["/etc/vservers.conf", self.config_file]:
53 self.config.update(self.__read_config_file(config_file))
55 if ex.errno != errno.ENOENT:
57 self.remove_caps = ~vserverimpl.CAP_SAFE;
59 self.vm_running = vm_running
61 config_var_re = re.compile(r"^ *([A-Z_]+)=(.*)\n?$", re.MULTILINE)
63 def __read_config_file(self, filename):
65 f = open(filename, "r")
69 for m in self.config_var_re.finditer(data):
70 (key, val) = m.groups()
71 config[key] = val.strip('"')
74 def __update_config_file(self, filename, newvars):
76 # read old file, apply changes
77 f = open(filename, "r")
82 for m in self.config_var_re.finditer(data):
83 (key, val) = m.groups()
84 newval = todo.pop(key, None)
86 data = data[:m.start(2)] + str(newval) + data[m.end(2):]
88 for (newkey, newval) in todo.items():
89 data += "%s=%s\n" % (newkey, newval)
96 newfile = filename + ".new"
97 f = open(newfile, "w")
101 # 'copy' original file, rename new to original
102 backup = filename + ".old"
106 if ex.errno != errno.ENOENT:
108 os.link(filename, backup)
109 os.rename(newfile, filename)
111 def __do_chroot(self):
116 def chroot_call(self, fn, *args):
118 cwd_fd = os.open(".", os.O_RDONLY)
120 root_fd = os.open("/", os.O_RDONLY)
133 def set_disklimit(self, block_limit):
135 # block_limit is in kB
137 vserverimpl.unsetdlimit(self.dir, self.ctx)
141 block_usage = vserverimpl.DLIMIT_KEEP
142 inode_usage = vserverimpl.DLIMIT_KEEP
144 # init_disk_info() must have been called to get usage values
145 block_usage = self.disk_blocks
146 inode_usage = self.disk_inodes
148 vserverimpl.setdlimit(self.dir,
153 vserverimpl.DLIMIT_INF, # inode limit
154 2) # %age reserved for root
156 def get_disklimit(self):
159 (self.disk_blocks, block_limit, self.disk_inodes, inode_limit,
160 reserved) = vserverimpl.getdlimit(self.dir, self.ctx)
162 if ex.errno != errno.ESRCH:
164 # get here if no vserver disk limit has been set for xid
169 def set_sched(self, cpu_share, sched_flags = 0):
171 if cpu_share == int(self.config.get("CPULIMIT", -1)):
173 cpu_guaranteed = sched_flags & SCHED_CPU_GUARANTEED
174 #cpu_guaranteed = int(self.resources.get("nm_sched_flags",
175 # None) == "guaranteed")
176 cpu_config = { "CPULIMIT": cpu_share, "CPUGUARANTEED": cpu_guaranteed }
177 self.__update_config_file(self.config_file, cpu_config)
179 vserverimpl.setsched(self.ctx, cpu_share, sched_flags)
182 # have no way of querying scheduler right now on a per vserver basis
185 def set_memlimit(self, limit):
186 ret = vserverimpl.setrlimit(self.ctx,5,limit)
189 def get_memlimit(self):
190 ret = vserverimpl.getrlimit(self.ctx,5)
193 def set_tasklimit(self, limit):
194 ret = vserverimpl.setrlimit(self.ctx,6,limit)
197 def get_tasklimit(self):
198 ret = vserverimpl.getrlimit(self.ctx,6)
201 def set_bwlimit(self, maxrate, minrate = 1, share = None, dev = "eth0"):
204 bwlimit.on(self.ctx, dev, share, minrate, maxrate)
206 bwlimit.off(self.ctx, dev)
208 def get_bwlimit(self, dev = "eth0"):
210 # result of bwlimit.get is (ctx, share, minrate, maxrate)
211 return bwlimit.get(self.ctx)[1:]
213 def open(self, filename, mode = "r", bufsize = -1):
215 return self.chroot_call(open, filename, mode, bufsize)
217 def __do_chcontext(self, state_file):
220 print >>state_file, "S_CONTEXT=%u" % self.ctx
221 print >>state_file, "S_PROFILE="
224 if vserverimpl.chcontext(self.ctx):
226 vserverimpl.setup_done(self.ctx)
228 def __prep(self, runlevel, log):
230 """ Perform all the crap that the vserver script does before
231 actually executing the startup scripts. """
233 # remove /var/run and /var/lock/subsys files
234 # but don't remove utmp from the top-level /var/run
236 LOCKDIR = "/var/lock/subsys"
237 filter_fn = lambda fs: filter(lambda f: f != 'utmp', fs)
238 garbage = reduce((lambda (out, ff), (dir, subdirs, files):
239 (out + map((dir + "/").__add__, ff(files)),
241 list(os.walk(RUNDIR)),
243 garbage += filter(os.path.isfile, map((LOCKDIR + "/").__add__,
244 os.listdir(LOCKDIR)))
248 # set the initial runlevel
249 f = open(RUNDIR + "/utmp", "w")
250 utmp.set_runlevel(f, runlevel)
253 # mount /proc and /dev/pts
254 self.__do_mount("none", "/proc", "proc")
255 # XXX - magic mount options
256 self.__do_mount("none", "/dev/pts", "devpts", 0, "gid=5,mode=0620")
258 def __do_mount(self, *mount_args):
261 mountimpl.mount(*mount_args)
263 if ex.errno == errno.EBUSY:
264 # assume already mounted
270 state_file = open("/var/run/vservers/%s.ctx" % self.name, "w")
272 self.__do_chcontext(state_file)
274 def start(self, wait, runlevel = 3):
276 self.vm_running = True
278 child_pid = os.fork()
285 # open state file to record vserver info
286 state_file = open("/var/run/vservers/%s.ctx" % self.name, "w")
288 # use /dev/null for stdin, /var/log/boot.log for stdout/err
291 os.open("/dev/null", os.O_RDONLY)
293 log = open("/var/log/boot.log", "w", 0)
296 print >>log, ("%s: starting the virtual server %s" %
297 (time.asctime(time.gmtime()), self.name))
299 # perform pre-init cleanup
300 self.__prep(runlevel, log)
302 # execute each init script in turn
303 # XXX - we don't support all scripts that vserver script does
306 for cmd in self.INITSCRIPTS + [None]:
307 # wait for previous command to terminate, unless it
308 # is the last one and the caller has specified to wait
309 if cmd_pid and (cmd != None or wait):
311 os.waitpid(cmd_pid, 0)
313 print >>log, "error waiting for %s:" % cmd_pid
314 traceback.print_exc()
320 # fork and exec next command
324 # enter vserver context
325 self.__do_chcontext(state_file)
326 arg_subst = { 'runlevel': runlevel }
327 cmd_args = [cmd[0]] + map(lambda x: x % arg_subst,
329 print >>log, "executing '%s'" % " ".join(cmd_args)
330 os.execl(cmd[0], *cmd_args)
332 traceback.print_exc()
335 # don't want to write state_file multiple times
338 # we get here due to an exception in the top-level child process
339 except Exception, ex:
340 traceback.print_exc()
346 def set_resources(self):
348 """ Called when vserver context is entered for first time,
349 should be overridden by subclass. """
353 def update_resources(self, resources):
355 self.config.update(resources)
357 # write new values to configuration file
358 self.__update_config_file(self.config_file, resources)
360 def init_disk_info(self):
362 (self.disk_inodes, self.disk_blocks, size) = vduimpl.vdu(self.dir)
366 def stop(self, signal = signal.SIGKILL):
368 vserverimpl.killall(self.ctx, signal)
369 self.vm_running = False
373 def create(vm_name, static = False, ctor = VServer):
377 options += ['--static']
378 runcmd.run('vuseradd', options + [vm_name])
379 vm_id = pwd.getpwnam(vm_name)[2]
381 return ctor(vm_name, vm_id)