import fcntl
import os
import re
+import pwd
+import signal
import sys
import time
import traceback
import mountimpl
-import linuxcaps
-import passfdimpl
+import runcmd
import utmp
-import vserverimpl
-
-from util_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)
+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
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):
+ def __init__(self, name, vm_id = None, vm_running = False):
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
- self.ctx = int(self.config["S_CONTEXT"])
+ 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 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;
+ if vm_id == None:
+ vm_id = int(self.config['S_CONTEXT'])
+ self.ctx = vm_id
+ self.vm_running = vm_running
+
+ 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)
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
+ 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[: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)
+ changed = True
+
+ if not changed:
+ return
+
+ # write new file
+ newfile = filename + ".new"
+ f = open(newfile, "w")
+ f.write(data)
+ f.close()
+
+ # replace old file with new
+ os.rename(newfile, filename)
+
def __do_chroot(self):
- return os.chroot("%s/%s" % (VROOTDIR, self.name))
+ os.chroot(self.dir)
+ os.chdir("/")
- def open(self, filename, mode = "r", bufsize = -1):
+ def chroot_call(self, fn, *args):
- (sendsock, recvsock) = passfdimpl.socketpair()
- child_pid = os.fork()
- if child_pid == 0:
+ cwd_fd = os.open(".", os.O_RDONLY)
+ try:
+ root_fd = os.open("/", os.O_RDONLY)
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)
+ 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
- # parent process
+ 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
- # 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)
+ 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:
+ (self.disk_blocks, block_limit, self.disk_inodes, inode_limit,
+ reserved) = vserverimpl.getdlimit(self.dir, self.ctx)
except OSError, ex:
- if ex.errno != errno.EAGAIN:
- throw = lambda : __throw(ex)
- fd = 0
- os.close(recvsock)
- if not fd:
- throw()
+ if ex.errno != errno.ESRCH:
+ raise
+ # get here if no vserver disk limit has been set for xid
+ block_limit = -1
- return os.fdopen(fd, mode, bufsize)
+ return block_limit
- def __do_chcontext(self, state_file = None):
+ def set_sched_config(self, cpu_share, sched_flags):
- vserverimpl.chcontext(self.ctx, self.remove_caps)
- if not state_file:
+ """ 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
- print >>state_file, "S_CONTEXT=%d" % self.ctx
- print >>state_file, "S_PROFILE=%s" % self.config.get("S_PROFILE", "")
- state_file.close()
+ cpu_guaranteed = sched_flags & SCHED_CPU_GUARANTEED
+ cpu_config = { "CPULIMIT": cpu_share, "CPUGUARANTEED": cpu_guaranteed }
+ self.update_resources(cpu_config)
+ if self.vm_running:
+ 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_bwlimit(self, minrate = bwlimit.bwmin, maxrate = None,
+ exempt_min = None, exempt_max = None,
+ share = None, dev = "eth0"):
+
+ 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, dev = "eth0"):
+
+ result = bwlimit.get(self.ctx)
+ # result of bwlimit.get is (ctx, share, minrate, maxrate)
+ if result:
+ result = result[1:]
+ return result
+
+ def open(self, filename, mode = "r", bufsize = -1):
+
+ return self.chroot_call(open, filename, mode, bufsize)
+
+ def __do_chcontext(self, state_file):
+
+ if state_file:
+ print >>state_file, "S_CONTEXT=%u" % self.ctx
+ print >>state_file, "S_PROFILE="
+ state_file.close()
+
+ if vserverimpl.chcontext(self.ctx):
+ self.set_resources()
+ vserverimpl.setup_done(self.ctx)
def __prep(self, runlevel, log):
self.__do_chroot()
self.__do_chcontext(state_file)
- def start(self, runlevel = 3):
+ def start(self, wait, runlevel = 3):
+ self.vm_running = True
+ self.rlimits_changed = False
child_pid = os.fork()
if child_pid == 0:
# 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]:
- # don't bother waiting for last command to terminate
- if cmd == None:
- os._exit(0)
-
- # wait for previous command to terminate
- if cmd_pid:
+ # 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:
# 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)
+
+ # 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
+
+ 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)