X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=python%2Fvserver.py;h=de8c16460d5df66b28e998bd4300630c2a99042b;hb=9b74b47baed4fe49c1c08226ba56e59512c6f269;hp=9f1bb09109a0f065bad5c42e936c9b2bfe8d2169;hpb=d37aa68dfca7686b67caa7bed9b5f878849622c2;p=util-vserver.git diff --git a/python/vserver.py b/python/vserver.py index 9f1bb09..de8c164 100644 --- a/python/vserver.py +++ b/python/vserver.py @@ -1,20 +1,29 @@ # 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 mountimpl -import passfdimpl -import utmp -import vserverimpl, vduimpl +import vserverimpl import cpulimit, bwlimit - +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 # # these are the flags taken from the kernel linux/vserver/legacy.h @@ -28,92 +37,244 @@ 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: INITSCRIPTS = [('/etc/rc.vinit', 'start'), ('/etc/rc.d/rc', '%(runlevel)d')] - def __init__(self, name, vm_running = False, resources = {}): + def __init__(self, name, vm_id = None, vm_running = None): self.name = name - self.config_file = "/etc/vservers/%s.conf" % name + 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 Exception, "no such vserver: " + name - self.config = self.__read_config_file("/etc/vservers.conf") - self.config.update(self.__read_config_file(self.config_file)) - 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 + raise NoSuchVServer, "no such vserver: " + name + self.config = VServerConfig(name, "/etc/vservers/%s" % name) self.remove_caps = ~vserverimpl.CAP_SAFE; - self.ctx = int(self.config["S_CONTEXT"]) + 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 - self.resources = resources - - config_var_re = re.compile(r"^ *([A-Z_]+)=(.*)\n?$", re.MULTILINE) - def __read_config_file(self, filename): + def have_limits_changed(self): + return self.rlimits_changed - f = open(filename, "r") - data = f.read() - f.close() - config = {} - for m in self.config_var_re.finditer(data): - (key, val) = m.groups() - config[key] = val.strip('"') - return config - - def __update_config_file(self, filename, newvars): - - # read old file, apply changes - f = open(filename, "r") - data = f.read() - f.close() - todo = newvars.copy() + def set_rlimit_limit(self,type,hard,soft,minimum): + """Generic set resource limit function for vserver""" + global RLIMITS changed = False - for m in self.config_var_re.finditer(data): - (key, val) = m.groups() - newval = todo.pop(key, None) - if newval != None: - data = data[:m.start(2)] + str(newval) + data[m.end(2):] - changed = True - for (newkey, newval) in todo.items(): - data += "%s=%s\n" % (newkey, newval) - changed = True - - if not changed: - return + 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 - # write new file - newfile = filename + ".new" - f = open(newfile, "w") - f.write(data) - f.close() + 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) - # 'copy' original file, rename new to original - backup = filename + ".old" - try: - os.unlink(backup) - except OSError, ex: - if ex.errno != errno.ENOENT: - raise - os.link(filename, backup) - os.rename(newfile, filename) + 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 set_disklimit(self, block_limit): + 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 @@ -122,135 +283,92 @@ class VServer: block_usage = self.disk_blocks inode_usage = self.disk_inodes - vserverimpl.setdlimit(self.dir, - self.ctx, - block_usage, - block_limit, - inode_usage, - vserverimpl.DLIMIT_INF, # inode limit - 2) # %age reserved for root + 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: - blocksused, blocktotal, inodesused, inodestotal, reserved = \ - vserverimpl.getdlimit(self.dir, self.ctx) + (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: - # get here if no vserver disk limit has been set for xid - blocktotal = -1 + if ex.errno != errno.ESRCH: + raise + # get here if no vserver disk limit has been set for xid + block_limit = -1 - return blocktotal + return block_limit - def set_sched(self, cpu_share): + def set_sched_config(self, cpu_share, sched_flags): - if cpu_share == int(self.config.get("CPULIMIT", -1)): - return + """ 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) - self.__update_config_file(self.config_file, { "CPULIMIT": cpu_share }) if self.vm_running: - vserverimpl.setsched(self.ctx, self.resources) + 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_memlimit(self, limit): - ret = vserverimpl.setrlimit(self.ctx,5,limit) - return ret - - def get_memlimit(self): - ret = vserverimpl.getrlimit(self.ctx,5) - return ret - - def set_tasklimit(self, limit): - ret = vserverimpl.setrlimit(self.ctx,6,limit) - return ret - - def get_tasklimit(self): - ret = vserverimpl.getrlimit(self.ctx,6) - return ret + def set_bwlimit(self, minrate = bwlimit.bwmin, maxrate = None, + exempt_min = None, exempt_max = None, + share = None, dev = "eth0"): - def set_bwlimit(self, eth, limit, cap, minrate, maxrate): - if cap == "-1": - bwlimit.off(self.ctx,eth) + if minrate is None: + bwlimit.off(self.ctx, dev) else: - bwlimit.on(self.ctx, eth, limit, cap, minrate, maxrate) - - def get_bwlimit(self, eth): - # not implemented yet - bwlimit = -1 - cap = "unknown" - minrate = "unknown" - maxrate = "unknown" - return (bwlimit, cap, minrate, maxrate) - - def open(self, filename, mode = "r", bufsize = -1): - - (sendsock, recvsock) = passfdimpl.socketpair() - child_pid = os.fork() - if child_pid == 0: - try: - # child process - self.__do_chroot() - f = open(filename, mode) - passfdimpl.sendmsg(f.fileno(), sendsock) - os._exit(0) - except EnvironmentError, ex: - (result, errmsg) = (ex.errno, ex.strerror) - except Exception, ex: - (result, errmsg) = (255, str(ex)) - os.write(sendsock, errmsg) - os._exit(result) + bwlimit.on(self.ctx, dev, share, + minrate, maxrate, exempt_min, exempt_max) - # parent process + def get_bwlimit(self, dev = "eth0"): - # XXX - need this since a lambda can't raise an exception - def __throw(ex): - raise ex + result = bwlimit.get(self.ctx) + # result of bwlimit.get is (ctx, share, minrate, maxrate) + if result: + result = result[1:] + return result - 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() + def open(self, filename, mode = "r", bufsize = -1): - return os.fdopen(fd, mode, bufsize) + return self.chroot_call(open, filename, mode, bufsize) def __do_chcontext(self, state_file): - vserverimpl.chcontext(self.ctx, self.resources) + if state_file: + print >>state_file, "%u" % self.ctx + state_file.close() - if not state_file: - return - print >>state_file, "S_CONTEXT=%d" % self.ctx - print >>state_file, "S_PROFILE=%s" % self.config.get("S_PROFILE", "") - 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): @@ -269,23 +387,24 @@ class VServer: ([], filter_fn))[0] garbage += filter(os.path.isfile, map((LOCKDIR + "/").__add__, os.listdir(LOCKDIR))) - for f in garbage: - os.unlink(f) + if False: + for f in garbage: + os.unlink(f) # set the initial runlevel f = open(RUNDIR + "/utmp", "w") - utmp.set_runlevel(f, runlevel) + vserverimpl.setrunlevel(f, runlevel) f.close() # mount /proc and /dev/pts - self.__do_mount("none", "/proc", "proc") + self.__do_mount("none", self.dir, "/proc", "proc") # XXX - magic mount options - self.__do_mount("none", "/dev/pts", "devpts", 0, "gid=5,mode=0620") + self.__do_mount("none", self.dir, "/dev/pts", "devpts", 0, "gid=5,mode=0620") def __do_mount(self, *mount_args): try: - mountimpl.mount(*mount_args) + vserverimpl.mount(*mount_args) except OSError, ex: if ex.errno == errno.EBUSY: # assume already mounted @@ -293,14 +412,12 @@ class VServer: raise ex def enter(self): - - state_file = open("/var/run/vservers/%s.ctx" % self.name, "w") self.__do_chroot() - self.__do_chcontext(state_file) + self.__do_chcontext(None) def start(self, wait, runlevel = 3): - self.vm_running = True + self.rlimits_changed = False child_pid = os.fork() if child_pid == 0: @@ -310,16 +427,18 @@ class VServer: os.setsid() # open state file to record vserver info - state_file = open("/var/run/vservers/%s.ctx" % self.name, "w") + state_file = open("/var/run/vservers/%s" % self.name, "w") # use /dev/null for stdin, /var/log/boot.log for stdout/err - os.close(0) - os.close(1) - os.open("/dev/null", os.O_RDONLY) + 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) - # XXX - close all other fds print >>log, ("%s: starting the virtual server %s" % (time.asctime(time.gmtime()), self.name)) @@ -329,39 +448,18 @@ class VServer: # execute each init script in turn # XXX - we don't support all scripts that vserver script does - cmd_pid = 0 - first_child = True - for cmd in self.INITSCRIPTS + [None]: - # wait for previous command to terminate, unless it - # is the last one and the caller has specified to wait - if cmd_pid and (cmd != None or wait): - try: - os.waitpid(cmd_pid, 0) - except: - print >>log, "error waiting for %s:" % cmd_pid - traceback.print_exc() - - # end of list - if cmd == None: - os._exit(0) - - # fork and exec next command - cmd_pid = os.fork() - if cmd_pid == 0: - try: - # enter vserver context - self.__do_chcontext(state_file) - arg_subst = { 'runlevel': runlevel } - cmd_args = [cmd[0]] + map(lambda x: x % arg_subst, - cmd[1:]) - print >>log, "executing '%s'" % " ".join(cmd_args) - os.execl(cmd[0], *cmd_args) - except: - traceback.print_exc() - os._exit(1) - else: - # don't want to write state_file multiple times - state_file = None + 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: @@ -371,15 +469,53 @@ class VServer: # parent process return child_pid - def update_resources(self, resources): + def set_resources(self): - self.config.update(resources) + """ Called when vserver context is entered for first time, + should be overridden by subclass. """ - # write new values to configuration file - self.__update_config_file(self.config_file, resources) + 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] - (self.disk_inodes, self.disk_blocks, size) = vduimpl.vdu(self.dir) - - return size + return ctor(vm_name, vm_id)