3 There are a couple of tricky things going on here. First, the kernel
4 needs disk usage information in order to enforce the quota. However,
5 determining disk usage redundantly strains the disks. Thus, the
6 Sliver_VS.disk_usage_initialized flag is used to determine whether
7 this initialization has been made.
9 Second, it's not currently possible to set the scheduler parameters
10 for a sliver unless that sliver has a running process. /bin/vsh helps
11 us out by reading the configuration file so that it can set the
12 appropriate limits after entering the sliver context. Making the
13 syscall that actually sets the parameters gives a harmless error if no
14 process is running. Thus we keep vm_running on when setting scheduler
15 parameters so that set_sched_params() always makes the syscall, and we
16 don't have to guess if there is a running process or not.
28 class Sliver_VS(accounts.Account, vserver.VServer):
29 """This class wraps vserver.VServer to make its interface closer to what we need for the Node Manager."""
32 TYPE = 'sliver.VServer'
34 def __init__(self, rec):
35 vserver.VServer.__init__(self, rec['name'])
39 self.disk_usage_initialized = False
43 def create(name): logger.log_call('/usr/sbin/vuseradd', name)
46 def destroy(name): logger.log_call('/usr/sbin/vuserdel', name)
48 def configure(self, rec):
49 new_rspec = rec['_rspec']
50 if new_rspec != self.rspec:
51 self.rspec = new_rspec
54 new_initscript = rec['initscript']
55 if new_initscript != self.initscript:
56 self.initscript = new_initscript
57 logger.log('%s: installing initscript' % self.name)
58 def install_initscript():
59 flags = os.O_WRONLY | os.O_CREAT | os.O_TRUNC
60 fd = os.open('/etc/rc.vinit', flags, 0755)
61 os.write(fd, new_initscript)
63 try: self.chroot_call(install_initscript)
64 except: logger.log_exc()
66 accounts.Account.configure(self, rec) # install ssh keys
69 if self.rspec['enabled']:
70 logger.log('%s: starting' % self.name)
73 # VServer.start calls fork() internally, so just close the nonstandard fds and fork once to avoid creating zombies
74 tools.close_nonstandard_fds()
75 vserver.VServer.start(self, True)
77 else: os.waitpid(child_pid, 0)
78 else: logger.log('%s: not starting, is not enabled' % self.name)
81 logger.log('%s: stopping' % self.name)
82 vserver.VServer.stop(self)
84 def set_resources(self):
85 disk_max = self.rspec['disk_max']
86 logger.log('%s: setting max disk usage to %d KiB' % (self.name, disk_max))
87 try: # if the sliver is over quota, .set_disk_limit will throw an exception
88 if not self.disk_usage_initialized:
89 self.vm_running = False
90 logger.log('%s: computing disk usage' % self.name)
92 self.disk_usage_initialized = True
93 vserver.VServer.set_disklimit(self, disk_max)
94 except OSError: logger.log_exc()
96 net_limits = (self.rspec['net_min'], self.rspec['net_max'], self.rspec['net2_min'], self.rspec['net2_max'], self.rspec['net_share'])
97 logger.log('%s: setting net limits to %s bps' % (self.name, net_limits[:-1]))
98 logger.log('%s: setting net share to %d' % (self.name, net_limits[-1]))
99 self.set_bwlimit(*net_limits)
101 cpu_min = self.rspec['cpu_min']
102 cpu_share = self.rspec['cpu_share']
103 if self.rspec['enabled']:
105 logger.log('%s: setting cpu share to %d%% guaranteed' % (self.name, cpu_min/10.0))
106 self.set_sched_config(cpu_min, vserver.SCHED_CPU_GUARANTEED)
108 logger.log('%s: setting cpu share to %d' % (self.name, cpu_share))
109 self.set_sched_config(cpu_share, 0)
110 else: # tell vsh to disable remote login by setting CPULIMIT to 0
111 logger.log('%s: disabling remote login' % self.name)
112 self.set_sched_config(0, 0)