X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=python%2Fvserver.py;h=cf0b84eaea4554554e6e2db553333c20f513c4cc;hb=42e63a53a5f87b428e35d4a024a903e15a20b5de;hp=ee061bbf693936c7e15de3e1c1448560ba20cd23;hpb=f061f5d3ea230ebc5132315131c00852ffb58269;p=util-vserver.git diff --git a/python/vserver.py b/python/vserver.py index ee061bb..cf0b84e 100644 --- a/python/vserver.py +++ b/python/vserver.py @@ -4,18 +4,35 @@ import errno import fcntl import os import re +import pwd import signal import sys import time import traceback import mountimpl -import passfdimpl +import runcmd import utmp import vserverimpl, vduimpl 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 RLIMIT_CPU +from vserverimpl import RLIMIT_RSS +from vserverimpl import RLIMIT_NPROC +from vserverimpl import RLIMIT_NOFILE +from vserverimpl import RLIMIT_MEMLOCK +from vserverimpl import RLIMIT_AS +from vserverimpl import RLIMIT_LOCKS +from vserverimpl import RLIMIT_SIGPENDING +from vserverimpl import RLIMIT_MSGQUEUE +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 @@ -29,21 +46,37 @@ FLAGS_HIDEINFO = 32 FLAGS_ULIMIT = 64 FLAGS_NAMESPACE = 128 +RLIMITS = {"CPU": RLIMIT_CPU, + "RSS": RLIMIT_RSS, + "NPROC": RLIMIT_NPROC, + "NOFILE": RLIMIT_NOFILE, + "MEMLOCK": RLIMIT_MEMLOCK, + "AS": RLIMIT_AS, + "LOCKS": RLIMIT_LOCKS, + "SIGPENDING": RLIMIT_SIGPENDING, + "MSGQUEUE": RLIMIT_MSGQUEUE, + "NSOCK": VLIMIT_NSOCK, + "OPENFD": VLIMIT_OPENFD, + "ANON": VLIMIT_ANON, + "SHMEM": VLIMIT_SHMEM} + +class NoSuchVServer(Exception): pass + - class VServer: INITSCRIPTS = [('/etc/rc.vinit', 'start'), ('/etc/rc.d/rc', '%(runlevel)d')] - def __init__(self, name, vm_id, vm_running = False, resources = {}): + def __init__(self, name, vm_id = None, vm_running = False): self.name = name + self.rlimits_changed = False self.config_file = "/etc/vservers/%s.conf" % name 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 + raise NoSuchVServer, "no such vserver: " + name self.config = {} for config_file in ["/etc/vservers.conf", self.config_file]: try: @@ -52,9 +85,67 @@ class VServer: if ex.errno != errno.ENOENT: raise self.remove_caps = ~vserverimpl.CAP_SAFE; + if vm_id == None: + vm_id = int(self.config['S_CONTEXT']) self.ctx = vm_id self.vm_running = vm_running - self.resources = resources + + 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""" + resources = {} + if hard <> VC_LIM_KEEP: + resources["VS_%s_HARD"%type] = hard + if soft <> VC_LIM_KEEP: + resources["VS_%s_SOFT"%type] = soft + if minimum <> VC_LIM_KEEP: + resources["VS_%s_MINIMUM"%type] = minimum + if len(resources)>0: + self.update_resources(resources) + 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("VS_%s_HARD"%type,VC_LIM_KEEP)) + soft = int(self.config.get("VS_%s_SOFT"%type,VC_LIM_KEEP)) + minimum = int(self.config.get("VS_%s_MINIMUM"%type,VC_LIM_KEEP)) + return (hard,soft,minimum) + + def set_WHITELISTED_config(self,whitelisted): + resources = {'VS_WHITELISTED': whitelisted} + self.update_resources(resources) config_var_re = re.compile(r"^ *([A-Z_]+)=(.*)\n?$", re.MULTILINE) @@ -77,11 +168,13 @@ class VServer: f.close() todo = newvars.copy() changed = False + offset = 0 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):] + data = data[:offset+m.start(2)] + str(newval) + data[offset+m.end(2):] + offset += len(str(newval)) - (m.end(2)-m.start(2)) changed = True for (newkey, newval) in todo.items(): data += "%s=%s\n" % (newkey, newval) @@ -96,14 +189,7 @@ class VServer: f.write(data) f.close() - # '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) + # replace old file with new os.rename(newfile, filename) def __do_chroot(self): @@ -111,11 +197,30 @@ class VServer: 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: - vserverimpl.unsetdlimit(self.dir, self.ctx) + 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: @@ -126,14 +231,25 @@ 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 + + + resources = {'VS_DISK_MAX': block_limit} + self.update_resources(resources) + + def is_running(self): + return vserverimpl.isrunning(self.ctx) + def get_disklimit(self): try: @@ -147,110 +263,49 @@ class VServer: return block_limit - def set_sched(self, cpu_share): + 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 cpu_share == int(self.config.get("CPULIMIT", -1)): return - # XXX - don't want to have to deal with nm_ flags here - cpu_guaranteed = int(self.resources.get("nm_sched_flags", - None) == "guaranteed") + cpu_guaranteed = sched_flags & SCHED_CPU_GUARANTEED cpu_config = { "CPULIMIT": cpu_share, "CPUGUARANTEED": cpu_guaranteed } - self.__update_config_file(self.config_file, cpu_config) + self.update_resources(cpu_config) if self.vm_running: - # caller must ensure cpu_share is consistent with self.resources - 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, share, minrate = 1, maxrate = None, dev = "eth0"): + def set_bwlimit(self, minrate = bwlimit.bwmin, maxrate = None, + exempt_min = None, exempt_max = None, + share = None, dev = "eth0"): - if share: - bwlimit.on(self.ctx, dev, share, minrate, maxrate) - else: + 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, 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) - - # 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): @@ -259,7 +314,9 @@ class VServer: print >>state_file, "S_PROFILE=" state_file.close() - vserverimpl.chcontext(self.ctx, self.resources) + if vserverimpl.chcontext(self.ctx): + self.set_resources() + vserverimpl.setup_done(self.ctx) def __prep(self, runlevel, log): @@ -278,8 +335,9 @@ 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") @@ -308,8 +366,8 @@ class VServer: self.__do_chcontext(state_file) def start(self, wait, runlevel = 3): - self.vm_running = True + self.rlimits_changed = False child_pid = os.fork() if child_pid == 0: @@ -337,39 +395,18 @@ 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 + [None]: + 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_WAIT,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: @@ -379,6 +416,13 @@ class VServer: # parent process return child_pid + def set_resources(self): + + """ Called when vserver context is entered for first time, + should be overridden by subclass. """ + + pass + def update_resources(self, resources): self.config.update(resources) @@ -393,6 +437,18 @@ class VServer: return size 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 = [] + if static: + options += ['--static'] + runcmd.run('vuseradd', options + [vm_name]) + vm_id = pwd.getpwnam(vm_name)[2] + + return ctor(vm_name, vm_id)