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 # special constant that tells vserver to keep its existing settings
30 KEEP_LIMIT = vserver.VC_LIM_KEEP
32 # populate the sliver/vserver specific default allocations table,
33 # which is used to look for slice attributes
34 DEFAULT_ALLOCATION = {}
35 for rlimit in vserver.RLIMITS.keys():
37 DEFAULT_ALLOCATION["%s_min"%rlim]=KEEP_LIMIT
38 DEFAULT_ALLOCATION["%s_soft"%rlim]=KEEP_LIMIT
39 DEFAULT_ALLOCATION["%s_hard"%rlim]=KEEP_LIMIT
41 class Sliver_VS(accounts.Account, vserver.VServer):
42 """This class wraps vserver.VServer to make its interface closer to what we need."""
45 TYPE = 'sliver.VServer'
46 _init_disk_info_sem = threading.Semaphore(1)
48 def __init__(self, rec):
50 vserver.VServer.__init__(self, rec['name'])
51 except Exception, err:
52 if not isinstance(err, vserver.NoSuchVServer):
53 # Probably a bad vserver or vserver configuration file
55 logger.log('%s: recreating bad vserver' % rec['name'])
56 self.destroy(rec['name'])
57 self.create(rec['name'], rec['vref'])
58 vserver.VServer.__init__(self, rec['name'])
63 self.disk_usage_initialized = False
67 def create(name, vref = None):
69 logger.log_call('/usr/sbin/vuseradd', '-t', vref, name)
71 logger.log_call('/usr/sbin/vuseradd', name)
72 open('/vservers/%s/etc/slicename' % name, 'w').write(name)
75 def destroy(name): logger.log_call('/usr/sbin/vuserdel', name)
77 def configure(self, rec):
78 new_rspec = rec['_rspec']
79 if new_rspec != self.rspec:
80 self.rspec = new_rspec
83 new_initscript = rec['initscript']
84 if new_initscript != self.initscript:
85 self.initscript = new_initscript
86 logger.log('%s: installing initscript' % self.name)
87 def install_initscript():
88 flags = os.O_WRONLY | os.O_CREAT | os.O_TRUNC
89 fd = os.open('/etc/rc.vinit', flags, 0755)
90 os.write(fd, new_initscript)
92 try: self.chroot_call(install_initscript)
93 except: logger.log_exc()
95 accounts.Account.configure(self, rec) # install ssh keys
97 def start(self, delay=0):
98 if self.rspec['enabled'] > 0:
99 logger.log('%s: starting in %d seconds' % (self.name, delay))
101 child_pid = os.fork()
103 # VServer.start calls fork() internally, so just close the nonstandard fds and fork once to avoid creating zombies
104 tools.close_nonstandard_fds()
105 vserver.VServer.start(self, True)
107 else: os.waitpid(child_pid, 0)
108 else: logger.log('%s: not starting, is not enabled' % self.name)
111 logger.log('%s: stopping' % self.name)
112 vserver.VServer.stop(self)
114 def set_resources(self):
115 disk_max = self.rspec['disk_max']
116 logger.log('%s: setting max disk usage to %d KiB' % (self.name, disk_max))
117 try: # if the sliver is over quota, .set_disk_limit will throw an exception
118 if not self.disk_usage_initialized:
119 self.vm_running = False
120 logger.log('%s: computing disk usage: beginning' % self.name)
121 Sliver_VS._init_disk_info_sem.acquire()
122 try: self.init_disk_info()
123 finally: Sliver_VS._init_disk_info_sem.release()
124 logger.log('%s: computing disk usage: ended' % self.name)
125 self.disk_usage_initialized = True
126 vserver.VServer.set_disklimit(self, disk_max)
128 logger.log('%s: failed to set max disk usage' % self.name)
131 # get/set the min/soft/hard values for all of the vserver
132 # related RLIMITS. Note that vserver currently only
133 # implements support for hard limits.
134 for limit in vserver.RLIMITS.keys():
136 minimum = self.rspec['%s_min'%type]
137 soft = self.rspec['%s_soft'%type]
138 hard = self.rspec['%s_hard'%type]
139 self.set_rlimit_config(limit, hard, soft, minimum)
141 self.set_WHITELISTED_config(self.rspec['whitelist'])
143 if False: # this code was commented out before
144 # N.B. net_*_rate are in kbps because of XML-RPC maxint
145 # limitations, convert to bps which is what bwlimit.py expects.
146 net_limits = (self.rspec['net_min_rate'] * 1000,
147 self.rspec['net_max_rate'] * 1000,
148 self.rspec['net_i2_min_rate'] * 1000,
149 self.rspec['net_i2_max_rate'] * 1000,
150 self.rspec['net_share'])
151 logger.log('%s: setting net limits to %s bps' % (self.name, net_limits[:-1]))
152 logger.log('%s: setting net share to %d' % (self.name, net_limits[-1]))
153 self.set_bwlimit(*net_limits)
155 cpu_min = self.rspec['cpu_min']
156 cpu_share = self.rspec['cpu_share']
158 if self.rspec['enabled'] > 0 and self.rspec['whitelist'] == 1:
159 if cpu_min >= 50: # at least 5%: keep people from shooting themselves in the foot
160 logger.log('%s: setting cpu share to %d%% guaranteed' % (self.name, cpu_min/10.0))
161 self.set_sched_config(cpu_min, vserver.SCHED_CPU_GUARANTEED)
163 logger.log('%s: setting cpu share to %d' % (self.name, cpu_share))
164 self.set_sched_config(cpu_share, 0)
166 if False: # Does not work properly yet.
167 if self.have_limits_changed():
168 logger.log('%s: limits have changed --- restarting' % self.name)
170 while self.is_running() and stopcount > 0:
174 stopcount = stopcount - 1
177 else: # tell vsh to disable remote login by setting CPULIMIT to 0
178 logger.log('%s: disabling remote login' % self.name)
179 self.set_sched_config(0, 0)