--- /dev/null
+# Copyright 2005 Princeton University
+
+import errno
+import fcntl
+import os
+import re
+import sys
+import time
+import traceback
+
+import mountimpl
+import passfdimpl
+import utmp
+import vserverimpl, vduimpl
+import cpulimit, bwlimit
+
+
+
+#
+# these are the flags taken from the kernel linux/vserver/legacy.h
+#
+FLAGS_LOCK = 1
+FLAGS_SCHED = 2 # XXX - defined in util-vserver/src/chcontext.c
+FLAGS_NPROC = 4
+FLAGS_PRIVATE = 8
+FLAGS_INIT = 16
+FLAGS_HIDEINFO = 32
+FLAGS_ULIMIT = 64
+FLAGS_NAMESPACE = 128
+
+
+
+class VServer:
+
+ INITSCRIPTS = [('/etc/rc.vinit', 'start'),
+ ('/etc/rc.d/rc', '%(runlevel)d')]
+
+ def __init__(self, name, vm_running = False, resources = {}):
+
+ 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
+ self.remove_caps = ~vserverimpl.CAP_SAFE;
+ self.ctx = int(self.config["S_CONTEXT"])
+ 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):
+
+ 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()
+ 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 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
+ if block_limit < block_usage:
+ raise Exception, ("%s disk usage (%u blocks) > limit (%u)" %
+ (self.name, block_usage, block_limit))
+
+ 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:
+ # get here if no vserver disk limit has been set for xid
+ # set blockused to -1 to indicate no limit
+ 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, cpu_share, True)
+
+ 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, 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):
+
+ (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
+
+ # XXX - need this since a lambda can't raise an exception
+ def __throw(ex):
+ raise ex
+
+ 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, 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
git://git.onelab.eu / util-vserver.git / blobdiff