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.
30 class Sliver_VS(accounts.Account, vserver.VServer):
31 """This class wraps vserver.VServer to make its interface closer to what we need."""
34 TYPE = 'sliver.VServer'
35 _init_disk_info_sem = threading.Semaphore(1)
37 def __init__(self, rec):
39 vserver.VServer.__init__(self, rec['name'])
40 except Exception, err:
41 if not isinstance(err, vserver.NoSuchVServer):
42 # Probably a bad vserver or vserver configuration file
44 logger.log('%s: recreating bad vserver' % rec['name'])
45 self.destroy(rec['name'])
46 self.create(rec['name'], rec['vref'])
47 vserver.VServer.__init__(self, rec['name'])
52 self.disk_usage_initialized = False
56 def create(name, vref = None):
58 logger.log_call('/usr/sbin/vuseradd', '-t', vref, name)
60 logger.log_call('/usr/sbin/vuseradd', name)
61 open('/vservers/%s/etc/slicename' % name, 'w').write(name)
64 def destroy(name): logger.log_call('/usr/sbin/vuserdel', name)
66 def configure(self, rec):
67 new_rspec = rec['_rspec']
68 if new_rspec != self.rspec:
69 self.rspec = new_rspec
72 new_initscript = rec['initscript']
73 if new_initscript != self.initscript:
74 self.initscript = new_initscript
75 logger.log('%s: installing initscript' % self.name)
76 def install_initscript():
77 flags = os.O_WRONLY | os.O_CREAT | os.O_TRUNC
78 fd = os.open('/etc/rc.vinit', flags, 0755)
79 os.write(fd, new_initscript)
81 try: self.chroot_call(install_initscript)
82 except: logger.log_exc()
84 accounts.Account.configure(self, rec) # install ssh keys
86 def start(self, delay=0):
87 if self.rspec['enabled'] > 0:
88 logger.log('%s: starting in %d seconds' % (self.name, delay))
92 # VServer.start calls fork() internally, so just close the nonstandard fds and fork once to avoid creating zombies
93 tools.close_nonstandard_fds()
94 vserver.VServer.start(self, True)
96 else: os.waitpid(child_pid, 0)
97 else: logger.log('%s: not starting, is not enabled' % self.name)
100 logger.log('%s: stopping' % self.name)
101 vserver.VServer.stop(self)
103 def set_resources(self):
104 disk_max = self.rspec['disk_max']
105 logger.log('%s: setting max disk usage to %d KiB' % (self.name, disk_max))
106 try: # if the sliver is over quota, .set_disk_limit will throw an exception
107 if not self.disk_usage_initialized:
108 self.vm_running = False
109 logger.log('%s: computing disk usage: beginning' % self.name)
110 Sliver_VS._init_disk_info_sem.acquire()
111 try: self.init_disk_info()
112 finally: Sliver_VS._init_disk_info_sem.release()
113 logger.log('%s: computing disk usage: ended' % self.name)
114 self.disk_usage_initialized = True
115 vserver.VServer.set_disklimit(self, disk_max)
117 logger.log('%s: failed to set max disk usage' % self.name)
120 # N.B. net_*_rate are in kbps because of XML-RPC maxint
121 # limitations, convert to bps which is what bwlimit.py expects.
122 # net_limits = (self.rspec['net_min_rate'] * 1000,
123 # self.rspec['net_max_rate'] * 1000,
124 # self.rspec['net_i2_min_rate'] * 1000,
125 # self.rspec['net_i2_max_rate'] * 1000,
126 # self.rspec['net_share'])
127 # logger.log('%s: setting net limits to %s bps' % (self.name, net_limits[:-1]))
128 # logger.log('%s: setting net share to %d' % (self.name, net_limits[-1]))
129 # self.set_bwlimit(*net_limits)
131 cpu_min = self.rspec['cpu_min']
132 cpu_share = self.rspec['cpu_share']
133 if self.rspec['enabled'] > 0:
134 if cpu_min >= 50: # at least 5%: keep people from shooting themselves in the foot
135 logger.log('%s: setting cpu share to %d%% guaranteed' % (self.name, cpu_min/10.0))
136 self.set_sched_config(cpu_min, vserver.SCHED_CPU_GUARANTEED)
138 logger.log('%s: setting cpu share to %d' % (self.name, cpu_share))
139 self.set_sched_config(cpu_share, 0)
140 else: # tell vsh to disable remote login by setting CPULIMIT to 0
141 logger.log('%s: disabling remote login' % self.name)
142 self.set_sched_config(0, 0)