X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=python%2Fvserver.py;h=7132cd1c7f55dcf2d89b3e838ff099e2efc0de04;hb=87e1702cad478ebc77f859d9bfff1f9008ecd194;hp=feeb02691c9ca5e7b528644c71eabe7276c6e1e1;hpb=471f8ae097d6c209b6cca044534aae586d514c00;p=util-vserver.git diff --git a/python/vserver.py b/python/vserver.py index feeb026..7132cd1 100644 --- a/python/vserver.py +++ b/python/vserver.py @@ -4,56 +4,56 @@ import errno import fcntl import os import re +import sys +import time +import traceback -import linuxcaps +import mountimpl import passfdimpl +import utmp +import vserverimpl, vduimpl +import cpulimit, bwlimit + -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) # -# 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 class VServer: - def __init__(self, name): + INITSCRIPTS = [('/etc/rc.vinit', 'start'), + ('/etc/rc.d/rc', '%(runlevel)d')] + + def __init__(self, name, vm_id, vm_running = False, resources = {}): 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) + 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 = {} + 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 = vm_id + self.vm_running = vm_running + self.resources = resources config_var_re = re.compile(r"^ *([A-Z_]+)=(.*)\n?$", re.MULTILINE) @@ -68,14 +68,136 @@ class VServer: config[key] = val.strip('"') return config - def open(self, filename, mode = "r"): + def __update_config_file(self, filename, newvars): + + # read old file, apply changes + f = open(filename, "r") + data = f.read() + f.close() + todo = newvars.copy() + 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 + + # write new file + newfile = filename + ".new" + f = open(newfile, "w") + 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) + os.rename(newfile, filename) + + def __do_chroot(self): + + os.chroot(self.dir) + os.chdir("/") + + def set_disklimit(self, block_limit): + + # block_limit is in kB + 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 + else: + # init_disk_info() must have been called to get usage values + 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 + + def get_disklimit(self): + + try: + blocksused, blocktotal, inodesused, inodestotal, 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 + blocktotal = -1 + + return blocktotal + + def set_sched(self, cpu_share): + + if cpu_share == int(self.config.get("CPULIMIT", -1)): + return + + self.__update_config_file(self.config_file, { "CPULIMIT": cpu_share }) + if self.vm_running: + vserverimpl.setsched(self.ctx, self.resources) + + 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"): + + if share: + bwlimit.on(self.ctx, dev, share, minrate, maxrate) + else: + bwlimit.off(self.ctx, dev) + + 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 - os.chroot("%s/%s" % (VROOTDIR, self.name)) + self.__do_chroot() f = open(filename, mode) passfdimpl.sendmsg(f.fileno(), sendsock) os._exit(0) @@ -123,4 +245,146 @@ class VServer: if not fd: throw() - return os.fdopen(fd) + return os.fdopen(fd, mode, bufsize) + + def __do_chcontext(self, state_file): + + vserverimpl.chcontext(self.ctx, self.resources) + + 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() + + 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))) + for f in garbage: + os.unlink(f) + + # set the initial runlevel + f = open(RUNDIR + "/utmp", "w") + utmp.set_runlevel(f, runlevel) + f.close() + + # mount /proc and /dev/pts + self.__do_mount("none", "/proc", "proc") + # XXX - magic mount options + self.__do_mount("none", "/dev/pts", "devpts", 0, "gid=5,mode=0620") + + def __do_mount(self, *mount_args): + + try: + mountimpl.mount(*mount_args) + except OSError, ex: + if ex.errno == errno.EBUSY: + # assume already mounted + return + raise ex + + def enter(self): + + state_file = open("/var/run/vservers/%s.ctx" % self.name, "w") + self.__do_chroot() + self.__do_chcontext(state_file) + + def start(self, wait, runlevel = 3): + + self.vm_running = True + + child_pid = os.fork() + if child_pid == 0: + # child process + try: + # get a new session + os.setsid() + + # open state file to record vserver info + state_file = open("/var/run/vservers/%s.ctx" % 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) + 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)) + + # 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 + 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 + + # we get here due to an exception in the top-level child process + except Exception, ex: + traceback.print_exc() + os._exit(0) + + # parent process + return child_pid + + def update_resources(self, resources): + + self.config.update(resources) + + # write new values to configuration file + self.__update_config_file(self.config_file, resources) + + def init_disk_info(self): + + (self.disk_inodes, self.disk_blocks, size) = vduimpl.vdu(self.dir) + + return size