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.
29 class Sliver_VS(accounts.Account, vserver.VServer):
30 """This class wraps vserver.VServer to make its interface closer to what we need."""
33 TYPE = 'sliver.VServer'
35 def __init__(self, rec):
37 vserver.VServer.__init__(self, rec['name'])
38 except vserver.NoSuchVServer:
39 self.create(rec['name'], rec['type'])
40 vserver.VServer.__init__(self, rec['name'])
45 self.disk_usage_initialized = False
49 def create(name, vref = None):
51 logger.log_call('/usr/sbin/vuseradd', '-t', vref, name)
53 logger.log_call('/usr/sbin/vuseradd', name)
56 def destroy(name): logger.log_call('/usr/sbin/vuserdel', name)
58 def configure(self, rec):
59 new_rspec = rec['_rspec']
60 if new_rspec != self.rspec:
61 self.rspec = new_rspec
64 new_initscript = rec['initscript']
65 if new_initscript != self.initscript:
66 self.initscript = new_initscript
67 logger.log('%s: installing initscript' % self.name)
68 def install_initscript():
69 flags = os.O_WRONLY | os.O_CREAT | os.O_TRUNC
70 fd = os.open('/etc/rc.vinit', flags, 0755)
71 os.write(fd, new_initscript)
73 try: self.chroot_call(install_initscript)
74 except: logger.log_exc()
76 accounts.Account.configure(self, rec) # install ssh keys
78 def start(self, delay=0):
79 if self.rspec['enabled']:
80 logger.log('%s: starting in %d seconds' % (self.name, delay))
83 # VServer.start calls fork() internally, so just close the nonstandard fds and fork once to avoid creating zombies
84 tools.close_nonstandard_fds()
86 vserver.VServer.start(self, True)
88 else: os.waitpid(child_pid, 0)
89 else: logger.log('%s: not starting, is not enabled' % self.name)
92 logger.log('%s: stopping' % self.name)
93 vserver.VServer.stop(self)
95 def set_resources(self):
96 disk_max = self.rspec['disk_max']
97 logger.log('%s: setting max disk usage to %d KiB' % (self.name, disk_max))
98 try: # if the sliver is over quota, .set_disk_limit will throw an exception
99 if not self.disk_usage_initialized:
100 self.vm_running = False
101 logger.log('%s: computing disk usage' % self.name)
102 self.init_disk_info()
103 self.disk_usage_initialized = True
104 vserver.VServer.set_disklimit(self, disk_max)
106 logger.log('%s: failed to set max disk usage' % self.name)
109 net_limits = (self.rspec['net_min'], self.rspec['net_max'], self.rspec['net2_min'], self.rspec['net2_max'], self.rspec['net_share'])
110 logger.log('%s: setting net limits to %s bps' % (self.name, net_limits[:-1]))
111 logger.log('%s: setting net share to %d' % (self.name, net_limits[-1]))
112 self.set_bwlimit(*net_limits)
114 cpu_min = self.rspec['cpu_min']
115 cpu_share = self.rspec['cpu_share']
116 if self.rspec['enabled']:
117 if cpu_min >= 50: # at least 5%: keep people from shooting themselves in the foot
118 logger.log('%s: setting cpu share to %d%% guaranteed' % (self.name, cpu_min/10.0))
119 self.set_sched_config(cpu_min, vserver.SCHED_CPU_GUARANTEED)
121 logger.log('%s: setting cpu share to %d' % (self.name, cpu_share))
122 self.set_sched_config(cpu_share, 0)
123 else: # tell vsh to disable remote login by setting CPULIMIT to 0
124 logger.log('%s: disabling remote login' % self.name)
125 self.set_sched_config(0, 0)