X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=python%2Fvserver.py;h=c6d07b625bcc5bcae34baf14b10b6f2d6cab551e;hb=8f38f0193db0dc219639aceac5f00641f31323af;hp=264aee22be081a78c15159602aec8eae03a28003;hpb=ab0d0363ca48b93f7f6c1b6fc19d4755ade0a309;p=util-vserver.git diff --git a/python/vserver.py b/python/vserver.py index 264aee2..c6d07b6 100644 --- a/python/vserver.py +++ b/python/vserver.py @@ -4,16 +4,21 @@ 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 + # @@ -29,32 +34,36 @@ FLAGS_ULIMIT = 64 FLAGS_NAMESPACE = 128 - + +class NoSuchVServer(Exception): pass + + + 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 = False): self.name = name 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 - 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 = {} + for config_file in ["/etc/vservers.conf", self.config_file]: + try: + self.config.update(self.__read_config_file(config_file)) + except IOError, ex: + if ex.errno != errno.ENOENT: + raise self.remove_caps = ~vserverimpl.CAP_SAFE; - self.ctx = int(self.config["S_CONTEXT"]) + if vm_id == None: + vm_id = int(self.config['S_CONTEXT']) + self.ctx = vm_id self.vm_running = vm_running - self.resources = resources config_var_re = re.compile(r"^ *([A-Z_]+)=(.*)\n?$", re.MULTILINE) @@ -77,11 +86,13 @@ 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 +107,7 @@ 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): @@ -111,10 +115,30 @@ class VServer: 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 - over_limit = False + if block_limit == 0: + vserverimpl.unsetdlimit(self.dir, self.ctx) + return + if self.vm_running: block_usage = vserverimpl.DLIMIT_KEEP inode_usage = vserverimpl.DLIMIT_KEEP @@ -122,8 +146,6 @@ class VServer: # init_disk_info() must have been called to get usage values block_usage = self.disk_blocks inode_usage = self.disk_inodes - if block_limit < block_usage: - over_limit = True vserverimpl.setdlimit(self.dir, self.ctx, @@ -133,31 +155,38 @@ class VServer: vserverimpl.DLIMIT_INF, # inode limit 2) # %age reserved for root - if over_limit: - raise Exception, ("%s disk usage (%u blocks) > limit (%u)" % - (self.name, block_usage, block_limit)) - 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 - # set blockused to -1 to indicate no limit - blocktotal = -1 + if ex.errno != errno.ESRCH: + raise + # get here if no vserver disk limit has been set for xid + block_limit = -1 + + return block_limit - return blocktotal + def set_sched_config(self, cpu_share, sched_flags): - def set_sched(self, cpu_share): + """ 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 - - self.__update_config_file(self.config_file, { "CPULIMIT": cpu_share }) + cpu_guaranteed = sched_flags & SCHED_CPU_GUARANTEED + cpu_config = { "CPULIMIT": cpu_share, "CPUGUARANTEED": cpu_guaranteed } + self.update_resources(cpu_config) if self.vm_running: - vserverimpl.setsched(self.ctx, cpu_share, True) + 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 @@ -179,86 +208,38 @@ class VServer: ret = vserverimpl.getrlimit(self.ctx,6) return ret - def set_bwlimit(self, eth, limit, cap, minrate, maxrate): - if cap == "-1": - bwlimit.off(self.ctx,eth) - 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): + def set_bwlimit(self, minrate = bwlimit.bwmin, maxrate = None, + exempt_min = None, exempt_max = None, + share = None, dev = "eth0"): - (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) + if minrate: + bwlimit.on(self.ctx, dev, share, + minrate, maxrate, exempt_min, exempt_max) + else: + bwlimit.off(self.ctx, dev) - # 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, "S_CONTEXT=%u" % self.ctx + print >>state_file, "S_PROFILE=" + 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): + self.set_resources() + vserverimpl.setup_done(self.ctx) def __prep(self, runlevel, log): @@ -327,7 +308,6 @@ class VServer: self.__do_chroot() log = open("/var/log/boot.log", "w", 0) os.dup2(1, 2) - # XXX - close all other fds print >>log, ("%s: starting the virtual server %s" % (time.asctime(time.gmtime()), self.name)) @@ -379,6 +359,13 @@ 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) @@ -391,3 +378,20 @@ class VServer: (self.disk_inodes, self.disk_blocks, size) = vduimpl.vdu(self.dir) return size + + def stop(self, signal = signal.SIGKILL): + + vserverimpl.killall(self.ctx, signal) + self.vm_running = 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)