X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=python%2Fvserver.py;h=139a9538456d9931edbe226d13876bb7f76c0687;hb=5a2624e82fc851f2f578183ec07d1a43841c6b9c;hp=9ee30d8e16cf4f604454e3cefc91792efbc0bf03;hpb=a526c473e1a658ee71aedc26313c8854f6abb8ec;p=util-vserver.git diff --git a/python/vserver.py b/python/vserver.py index 9ee30d8..139a953 100644 --- a/python/vserver.py +++ b/python/vserver.py @@ -4,16 +4,20 @@ 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 + # @@ -29,32 +33,34 @@ 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, 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"]) + self.ctx = vm_id self.vm_running = vm_running - self.resources = resources config_var_re = re.compile(r"^ *([A-Z_]+)=(.*)\n?$", re.MULTILINE) @@ -111,9 +117,30 @@ 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 + 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 @@ -121,9 +148,6 @@ 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: - raise Exception, ("%s disk usage (%u blocks) > limit (%u)" % - (self.name, block_usage, block_limit)) vserverimpl.setdlimit(self.dir, self.ctx, @@ -136,24 +160,35 @@ class VServer: 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 @@ -175,86 +210,32 @@ 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, maxrate, minrate = 1, 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 maxrate != 0: + bwlimit.on(self.ctx, dev, share, minrate, maxrate) + 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 of bwlimit.get is (ctx, share, minrate, maxrate) + return bwlimit.get(self.ctx)[1:] - 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): @@ -323,7 +304,6 @@ 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)) @@ -375,6 +355,13 @@ 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) @@ -387,3 +374,20 @@ 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)