X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=python%2Fvserver.py;h=de8c16460d5df66b28e998bd4300630c2a99042b;hb=9b74b47baed4fe49c1c08226ba56e59512c6f269;hp=feeb02691c9ca5e7b528644c71eabe7276c6e1e1;hpb=471f8ae097d6c209b6cca044534aae586d514c00;p=util-vserver.git diff --git a/python/vserver.py b/python/vserver.py index feeb026..de8c164 100644 --- a/python/vserver.py +++ b/python/vserver.py @@ -1,126 +1,521 @@ # Copyright 2005 Princeton University +#$Id: vserver.py,v 1.72 2007/08/02 16:01:59 dhozac Exp $ + import errno import fcntl import os import re +import pwd +import signal +import sys +import time +import traceback +import subprocess +import resource + +import vserverimpl +import cpulimit, bwlimit -import linuxcaps -import passfdimpl - -from vserver_vars import * - -CAP_SAFE = (linuxcaps.CAP_CHOWN | - linuxcaps.CAP_DAC_OVERRIDE | - linuxcaps.CAP_DAC_READ_SEARCH | - linuxcaps.CAP_FOWNER | - linuxcaps.CAP_FSETID | - linuxcaps.CAP_KILL | - linuxcaps.CAP_SETGID | - linuxcaps.CAP_SETUID | - linuxcaps.CAP_SETPCAP | - linuxcaps.CAP_SYS_TTY_CONFIG | - linuxcaps.CAP_LEASE | - linuxcaps.CAP_SYS_CHROOT | - linuxcaps.CAP_SYS_PTRACE) +from vserverimpl import VS_SCHED_CPU_GUARANTEED as SCHED_CPU_GUARANTEED +from vserverimpl import DLIMIT_INF +from vserverimpl import VC_LIM_KEEP +from vserverimpl import VLIMIT_NSOCK +from vserverimpl import VLIMIT_OPENFD +from vserverimpl import VLIMIT_ANON +from vserverimpl import VLIMIT_SHMEM # -# XXX - these are the flags taken from chcontext.c, but they don't match -# up with those apparently used by the kernel +# these are the flags taken from the kernel linux/vserver/legacy.h # FLAGS_LOCK = 1 -FLAGS_SCHED = 2 +FLAGS_SCHED = 2 # XXX - defined in util-vserver/src/chcontext.c FLAGS_NPROC = 4 FLAGS_PRIVATE = 8 -FLAGS_FAKEINIT = 16 +FLAGS_INIT = 16 FLAGS_HIDEINFO = 32 FLAGS_ULIMIT = 64 +FLAGS_NAMESPACE = 128 + +RLIMITS = { "NSOCK": VLIMIT_NSOCK, + "OPENFD": VLIMIT_OPENFD, + "ANON": VLIMIT_ANON, + "SHMEM": VLIMIT_SHMEM} + +# add in the platform supported rlimits +for entry in resource.__dict__.keys(): + if entry.find("RLIMIT_")==0: + k = entry[len("RLIMIT_"):] + if not RLIMITS.has_key(k): + RLIMITS[k]=resource.__dict__[entry] + else: + print "WARNING: duplicate RLIMITS key %s" % k + +class NoSuchVServer(Exception): pass + + +class VServerConfig: + def __init__(self, name, directory): + self.name = name + self.dir = directory + self.cache = None + if not (os.path.isdir(self.dir) and + os.access(self.dir, os.R_OK | os.W_OK | os.X_OK)): + raise NoSuchVServer, "%s does not exist" % self.dir + + def get(self, option, default = None): + try: + if self.cache: + return self.cache[option] + else: + f = open(os.path.join(self.dir, option), "r") + buf = f.read().rstrip() + f.close() + return buf + except: + if default is not None: + return default + else: + raise KeyError, "Key %s is not set for %s" % (option, self.name) + + def update(self, option, value): + if self.cache: + return + + try: + old_umask = os.umask(0022) + filename = os.path.join(self.dir, option) + try: + os.makedirs(os.path.dirname(filename), 0755) + except: + pass + f = open(filename, 'w') + if isinstance(value, list): + f.write("%s\n" % "\n".join(value)) + else: + f.write("%s\n" % value) + f.close() + os.umask(old_umask) + except: + raise + + def unset(self, option): + if self.cache: + return + + try: + filename = os.path.join(self.dir, option) + os.unlink(filename) + try: + os.removedirs(os.path.dirname(filename)) + except: + pass + return True + except: + return False + + def cache_it(self): + self.cache = {} + def add_to_cache(cache, dirname, fnames): + for file in fnames: + full_name = os.path.join(dirname, file) + if os.path.islink(full_name): + fnames.remove(file) + elif (os.path.isfile(full_name) and + os.access(full_name, os.R_OK)): + f = open(full_name, "r") + cache[full_name.replace(os.path.join(self.dir, ''), + '')] = f.read().rstrip() + f.close() + os.path.walk(self.dir, add_to_cache, self.cache) - class VServer: - def __init__(self, name): + INITSCRIPTS = [('/etc/rc.vinit', 'start'), + ('/etc/rc.d/rc', '%(runlevel)d')] + + def __init__(self, name, vm_id = None, vm_running = None): self.name = name - self.config = self.__read_config_file("/etc/vservers.conf") - self.config.update(self.__read_config_file("/etc/vservers/%s.conf" % - self.name)) - self.flags = 0 - flags = self.config["S_FLAGS"].split(" ") - if "lock" in flags: - self.flags |= FLAGS_LOCK - if "nproc" in flags: - self.flags |= FLAGS_NPROC - self.remove_caps = ~CAP_SAFE - print "%x %x" % (self.flags, ~self.remove_caps) - - config_var_re = re.compile(r"^ *([A-Z_]+)=(.*)\n?$", re.MULTILINE) - - def __read_config_file(self, filename): - - f = open(filename, "r") - data = f.read() + self.rlimits_changed = False + self.dir = "%s/%s" % (vserverimpl.VSERVER_BASEDIR, name) + if not (os.path.isdir(self.dir) and + os.access(self.dir, os.R_OK | os.W_OK | os.X_OK)): + raise NoSuchVServer, "no such vserver: " + name + self.config = VServerConfig(name, "/etc/vservers/%s" % name) + self.remove_caps = ~vserverimpl.CAP_SAFE; + if vm_id == None: + vm_id = int(self.config.get('context')) + self.ctx = vm_id + if vm_running == None: + vm_running = self.is_running() + self.vm_running = vm_running + + def have_limits_changed(self): + return self.rlimits_changed + + def set_rlimit_limit(self,type,hard,soft,minimum): + """Generic set resource limit function for vserver""" + global RLIMITS + changed = False + try: + old_hard, old_soft, old_minimum = self.get_rlimit_limit(type) + if old_hard != VC_LIM_KEEP and old_hard <> hard: changed = True + if old_soft != VC_LIM_KEEP and old_soft <> soft: changed = True + if old_minimum != VC_LIM_KEEP and old_minimum <> minimum: changed = True + self.rlimits_changed = self.rlimits_changed or changed + except OSError, e: + if self.is_running(): print "Unexpected error with getrlimit for running context %d" % self.ctx + + resource_type = RLIMITS[type] + try: + ret = vserverimpl.setrlimit(self.ctx,resource_type,hard,soft,minimum) + except OSError, e: + if self.is_running(): print "Unexpected error with setrlimit for running context %d" % self.ctx + + def set_rlimit_config(self,type,hard,soft,minimum): + """Generic set resource limit function for vserver""" + if hard <> VC_LIM_KEEP: + self.config.update('rlimits/%s.hard' % type.lower(), hard) + if soft <> VC_LIM_KEEP: + self.config.update('rlimits/%s.soft' % type.lower(), soft) + if minimum <> VC_LIM_KEEP: + self.config.update('rlimits/%s.min' % type.lower(), minimum) + self.set_rlimit_limit(type,hard,soft,minimum) + + def get_rlimit_limit(self,type): + """Generic get resource configuration function for vserver""" + global RLIMITS + resource_type = RLIMITS[type] + try: + ret = vserverimpl.getrlimit(self.ctx,resource_type) + except OSError, e: + print "Unexpected error with getrlimit for context %d" % self.ctx + ret = self.get_rlimit_config(type) + return ret + + def get_rlimit_config(self,type): + """Generic get resource configuration function for vserver""" + hard = int(self.config.get("rlimits/%s.hard"%type.lower(),VC_LIM_KEEP)) + soft = int(self.config.get("rlimits/%s.soft"%type.lower(),VC_LIM_KEEP)) + minimum = int(self.config.get("rlimits/%s.min"%type.lower(),VC_LIM_KEEP)) + return (hard,soft,minimum) + + def set_capabilities(self, capabilities): + return vserverimpl.setbcaps(self.ctx, vserverimpl.text2bcaps(capabilities)) + + def set_capabilities_config(self, capabilities): + self.config.update('bcapabilities', capabilities) + self.set_capabilities(capabilities) + + def get_capabilities(self): + return vserverimpl.bcaps2text(vserverimpl.getbcaps(self.ctx)) + + def get_capabilities_config(self): + return self.config.get('bcapabilities', '') + + def set_ipaddresses(self, addresses): + vserverimpl.netremove(self.ctx, "all") + for a in addresses.split(","): + vserverimpl.netadd(self.ctx, a) + + def set_ipaddresses_config(self, addresses): + i = 0 + for a in addresses.split(","): + self.config.update("interfaces/%d/ip" % i, a) + i += 1 + while self.config.unset("interfaces/%d/ip" % i): + i += 1 + self.set_ipaddresses(addresses) + + def get_ipaddresses_config(self): + i = 0 + ret = [] + while True: + r = self.config.get("interfaces/%d/ip" % i, '') + if r == '': + break + ret += [r] + i += 1 + return ",".join(ret) + + def get_ipaddresses(self): + # No clean way to do this right now. + return None + + def __do_chroot(self): + self.config.cache_it() + os.chroot(self.dir) + os.chdir("/") + + def chroot_call(self, fn, *args): + + cwd_fd = os.open(".", os.O_RDONLY) + try: + root_fd = os.open("/", os.O_RDONLY) + try: + self.__do_chroot() + result = fn(*args) + finally: + os.fchdir(root_fd) + os.chroot(".") + os.fchdir(cwd_fd) + os.close(root_fd) + finally: + os.close(cwd_fd) + return result + + def set_disklimit(self, block_limit): + # block_limit is in kB + if block_limit == 0: + try: + vserverimpl.unsetdlimit(self.dir, self.ctx) + except OSError, e: + print "Unexpected error with unsetdlimit for context %d" % self.ctx + return + + if self.vm_running: + block_usage = vserverimpl.DLIMIT_KEEP + inode_usage = vserverimpl.DLIMIT_KEEP + else: + # init_disk_info() must have been called to get usage values + block_usage = self.disk_blocks + inode_usage = self.disk_inodes + + + try: + vserverimpl.setdlimit(self.dir, + self.ctx, + block_usage, + block_limit, + inode_usage, + vserverimpl.DLIMIT_INF, # inode limit + 2) # %age reserved for root + except OSError, e: + print "Unexpected error with setdlimit for context %d" % self.ctx + + + self.config.update('dlimits/0/space_total', block_limit) + + def is_running(self): + return vserverimpl.isrunning(self.ctx) + + def get_disklimit(self): + + try: + (self.disk_blocks, block_limit, self.disk_inodes, inode_limit, + reserved) = vserverimpl.getdlimit(self.dir, self.ctx) + except OSError, ex: + if ex.errno != errno.ESRCH: + raise + # get here if no vserver disk limit has been set for xid + block_limit = -1 + + return block_limit + + def set_sched_config(self, cpu_share, sched_flags): + + """ Write current CPU scheduler parameters to the vserver + configuration file. This method does not modify the kernel CPU + scheduling parameters for this context. """ + + if sched_flags & SCHED_CPU_GUARANTEED: + cpu_guaranteed = cpu_share + else: + cpu_guaranteed = 0 + self.config.update('sched/fill-rate2', cpu_share) + self.config.update('sched/fill-rate', cpu_guaranteed) + + if self.vm_running: + self.set_sched(cpu_share, sched_flags) + + def set_sched(self, cpu_share, sched_flags = 0): + """ Update kernel CPU scheduling parameters for this context. """ + vserverimpl.setsched(self.ctx, cpu_share, sched_flags) + + def get_sched(self): + # have no way of querying scheduler right now on a per vserver basis + return (-1, False) + + def set_bwlimit(self, minrate = bwlimit.bwmin, maxrate = None, + exempt_min = None, exempt_max = None, + share = None, dev = "eth0"): + + if minrate is None: + bwlimit.off(self.ctx, dev) + else: + bwlimit.on(self.ctx, dev, share, + minrate, maxrate, exempt_min, exempt_max) + + def get_bwlimit(self, dev = "eth0"): + + result = bwlimit.get(self.ctx) + # result of bwlimit.get is (ctx, share, minrate, maxrate) + if result: + result = result[1:] + return result + + def open(self, filename, mode = "r", bufsize = -1): + + return self.chroot_call(open, filename, mode, bufsize) + + def __do_chcontext(self, state_file): + + if state_file: + print >>state_file, "%u" % self.ctx + state_file.close() + + if vserverimpl.chcontext(self.ctx, vserverimpl.text2bcaps(self.get_capabilities_config())): + self.set_resources() + vserverimpl.setup_done(self.ctx) + + def __prep(self, runlevel, log): + + """ Perform all the crap that the vserver script does before + actually executing the startup scripts. """ + + # remove /var/run and /var/lock/subsys files + # but don't remove utmp from the top-level /var/run + RUNDIR = "/var/run" + LOCKDIR = "/var/lock/subsys" + filter_fn = lambda fs: filter(lambda f: f != 'utmp', fs) + garbage = reduce((lambda (out, ff), (dir, subdirs, files): + (out + map((dir + "/").__add__, ff(files)), + lambda fs: fs)), + list(os.walk(RUNDIR)), + ([], filter_fn))[0] + garbage += filter(os.path.isfile, map((LOCKDIR + "/").__add__, + os.listdir(LOCKDIR))) + if False: + for f in garbage: + os.unlink(f) + + # set the initial runlevel + f = open(RUNDIR + "/utmp", "w") + vserverimpl.setrunlevel(f, runlevel) f.close() - config = {} - for m in self.config_var_re.finditer(data): - (key, val) = m.groups() - config[key] = val.strip('"') - return config - def open(self, filename, mode = "r"): + # mount /proc and /dev/pts + self.__do_mount("none", self.dir, "/proc", "proc") + # XXX - magic mount options + self.__do_mount("none", self.dir, "/dev/pts", "devpts", 0, "gid=5,mode=0620") + + def __do_mount(self, *mount_args): + + try: + vserverimpl.mount(*mount_args) + except OSError, ex: + if ex.errno == errno.EBUSY: + # assume already mounted + return + raise ex + + def enter(self): + self.__do_chroot() + self.__do_chcontext(None) + + def start(self, wait, runlevel = 3): + self.vm_running = True + self.rlimits_changed = False - (sendsock, recvsock) = passfdimpl.socketpair() child_pid = os.fork() if child_pid == 0: + # child process try: - # child process - os.chroot("%s/%s" % (VROOTDIR, self.name)) - f = open(filename, mode) - passfdimpl.sendmsg(f.fileno(), sendsock) - os._exit(0) - except EnvironmentError, ex: - (result, errmsg) = (ex.errno, ex.strerror) + # get a new session + os.setsid() + + # open state file to record vserver info + state_file = open("/var/run/vservers/%s" % self.name, "w") + + # use /dev/null for stdin, /var/log/boot.log for stdout/err + fd = os.open("/dev/null", os.O_RDONLY) + if fd != 0: + os.dup2(fd, 0) + os.close(fd) + self.__do_chroot() + log = open("/var/log/boot.log", "w", 0) + if log.fileno() != 1: + os.dup2(log.fileno(), 1) + os.dup2(1, 2) + + print >>log, ("%s: starting the virtual server %s" % + (time.asctime(time.gmtime()), self.name)) + + # perform pre-init cleanup + self.__prep(runlevel, log) + + # execute each init script in turn + # XXX - we don't support all scripts that vserver script does + self.__do_chcontext(state_file) + for cmd in self.INITSCRIPTS: + try: + # enter vserver context + arg_subst = { 'runlevel': runlevel } + cmd_args = [cmd[0]] + map(lambda x: x % arg_subst, + cmd[1:]) + print >>log, "executing '%s'" % " ".join(cmd_args) + os.spawnvp(os.P_NOWAIT,cmd[0],cmd_args) + except: + traceback.print_exc() + os._exit(1) + + # we get here due to an exception in the top-level child process except Exception, ex: - (result, errmsg) = (255, str(ex)) - os.write(sendsock, errmsg) - os._exit(result) + traceback.print_exc() + os._exit(0) # parent process + return child_pid - # XXX - need this since a lambda can't raise an exception - def __throw(ex): - raise ex + def set_resources(self): - os.close(sendsock) - throw = lambda : __throw(Exception(errmsg)) - while True: - try: - (pid, status) = os.waitpid(child_pid, 0) - if os.WIFEXITED(status): - result = os.WEXITSTATUS(status) - if result != 255: - errmsg = os.strerror(result) - throw = lambda : __throw(IOError(result, errmsg)) - else: - errmsg = "unexpected exception in child" - else: - result = -1 - errmsg = "child killed" - break - except OSError, ex: - if ex.errno != errno.EINTR: - os.close(recvsock) - raise ex - fcntl.fcntl(recvsock, fcntl.F_SETFL, os.O_NONBLOCK) - try: - (fd, errmsg) = passfdimpl.recvmsg(recvsock) - except OSError, ex: - if ex.errno != errno.EAGAIN: - throw = lambda : __throw(ex) - fd = 0 - os.close(recvsock) - if not fd: - throw() - - return os.fdopen(fd) + """ Called when vserver context is entered for first time, + should be overridden by subclass. """ + + pass + + def init_disk_info(self): + cmd = "/usr/sbin/vdu --script --space --inodes --blocksize 1024 --xid %d %s" % (self.ctx, self.dir) + p = subprocess.Popen(cmd, shell=True, stdin=subprocess.PIPE, + stdout=subprocess.PIPE, stderr=subprocess.PIPE, + close_fds=True) + p.stdin.close() + line = p.stdout.readline() + if not line: + sys.stderr.write(p.stderr.read()) + p.stdout.close() + p.stderr.close() + ret = p.wait() + + (space, inodes) = line.split() + self.disk_inodes = int(inodes) + self.disk_blocks = int(space) + #(self.disk_inodes, self.disk_blocks) = vduimpl.vdu(self.dir) + + return self.disk_blocks * 1024 + + def stop(self, signal = signal.SIGKILL): + vserverimpl.killall(self.ctx, signal) + self.vm_running = False + self.rlimits_changed = False + + + +def create(vm_name, static = False, ctor = VServer): + + options = ['vuseradd'] + if static: + options += ['--static'] + ret = os.spawnvp(os.P_WAIT, 'vuseradd', options + [vm_name]) + if !os.WIFEXITED(ret) || os.WEXITSTATUS(ret) != 0: + out = "system command ('%s') " % options + if os.WIFEXITED(ret): + out += "failed, rc = %d" % os.WEXITSTATUS(ret) + else: + out += "killed by signal %d" % os.WTERMSIG(ret) + raise SystemError, out + vm_id = pwd.getpwnam(vm_name)[2] + + return ctor(vm_name, vm_id)