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.
27 from threading import BoundedSemaphore
29 globalsem = BoundedSemaphore()
31 # special constant that tells vserver to keep its existing settings
32 KEEP_LIMIT = vserver.VC_LIM_KEEP
34 # populate the sliver/vserver specific default allocations table,
35 # which is used to look for slice attributes
36 DEFAULT_ALLOCATION = {}
37 for rlimit in vserver.RLIMITS.keys():
39 DEFAULT_ALLOCATION["%s_min"%rlim]=KEEP_LIMIT
40 DEFAULT_ALLOCATION["%s_soft"%rlim]=KEEP_LIMIT
41 DEFAULT_ALLOCATION["%s_hard"%rlim]=KEEP_LIMIT
43 class Sliver_VS(accounts.Account, vserver.VServer):
44 """This class wraps vserver.VServer to make its interface closer to what we need."""
47 TYPE = 'sliver.VServer'
48 _init_disk_info_sem = globalsem
50 def __init__(self, rec):
51 logger.verbose ('initing Sliver_VS with name=%s'%rec['name'])
53 vserver.VServer.__init__(self, rec['name'],logfile='/var/log/nm')
54 except Exception, err:
55 if not isinstance(err, vserver.NoSuchVServer):
56 # Probably a bad vserver or vserver configuration file
57 logger.log_exc(self.name)
58 logger.log('%s: recreating bad vserver' % rec['name'])
59 self.destroy(rec['name'])
60 self.create(rec['name'], rec['vref'])
61 vserver.VServer.__init__(self, rec['name'],logfile='/var/log/nm')
66 self.slice_id = rec['slice_id']
67 self.disk_usage_initialized = False
68 self.initscriptchanged = False
72 def create(name, vref = None):
73 logger.verbose('Sliver_VS:create - name=%s'%name)
77 ### locating the right slicefamily
78 # this is a first draft, and more a proof of concept thing
79 # the idea is to parse vref for dash-separated wishes,
80 # and to project these against the defaults
81 # so e.g. if the default slice family (as found in /etc/planetlab/slicefamily)
82 # is planetlab-f8-i386, then here is what we get
83 # vref=x86_64 -> vuseradd -t planetlab-f8-x86_64
84 # vref=centos5 -> vuseradd -t planetlab-centos5-i386
85 # vref=centos5-onelab -> vuseradd -t onelab-centos5-i386
86 # vref=planetflow -> vuseradd -t planetflow-f8-i386
87 # vref=x86_64-planetflow -> vuseradd -t planetflow-f8-x86_64
90 default=file("/etc/planetlab/slicefamily").read().strip()
91 (pldistro,fcdistro,arch) = default.split("-")
93 known_archs = [ 'i386', 'x86_64' ]
94 known_fcdistros = [ 'f8', 'f9', 'centos5' ]
95 # from the slice attribute: cut dashes and try to figure the meaning
96 slice_wishes = vref.split("-")
97 for wish in slice_wishes:
98 if wish in known_archs:
100 elif wish in known_fcdistros:
106 refname="-".join( (pldistro,fcdistro,arch) )
108 # check the templates exists -- there's probably a better way..
109 if not os.path.isdir ("/vservers/.vref/%s"%refname):
110 logger.verbose("%s (%s) : vref %s not found, using default %s"%(
111 name,vref,refname,default))
113 # could check again, but as we have /etc/slicefamily
114 # there's probably no /vservers/.vref/default
117 # have not found slicefamily
118 logger.verbose("%s (%s): legacy node - using fallback vrefname 'default'"%(name,vref))
123 logger.log("%s (%s) : unexpected error follows - using 'default'"%(
125 logger.log(traceback.format_exc())
128 logger.log_call('/usr/sbin/vuseradd', '-t', refname, name)
129 open('/vservers/%s/etc/slicename' % name, 'w').write(name)
132 def destroy(name): logger.log_call('/usr/sbin/vuserdel', name)
134 def configure(self, rec):
135 new_rspec = rec['_rspec']
136 if new_rspec != self.rspec:
137 self.rspec = new_rspec
140 new_initscript = rec['initscript']
141 if new_initscript != self.initscript:
142 self.initscript = new_initscript
143 logger.log('%s: installing initscript' % self.name)
144 def install_initscript():
145 flags = os.O_WRONLY | os.O_CREAT | os.O_TRUNC
146 fd = os.open('/etc/rc.vinit', flags, 0755)
147 os.write(fd, new_initscript)
150 self.chroot_call(install_initscript)
151 self.initscriptchanged = True
152 except: logger.log_exc(self.name)
154 accounts.Account.configure(self, rec) # install ssh keys
156 def start(self, delay=0):
157 if self.rspec['enabled'] > 0:
158 logger.log('%s: starting in %d seconds' % (self.name, delay))
160 child_pid = os.fork()
162 # VServer.start calls fork() internally,
163 # so just close the nonstandard fds and fork once to avoid creating zombies
164 tools.close_nonstandard_fds()
165 vserver.VServer.start(self)
167 else: os.waitpid(child_pid, 0)
168 else: logger.log('%s: not starting, is not enabled' % self.name)
169 self.initscriptchanged = False
172 logger.log('%s: stopping' % self.name)
173 vserver.VServer.stop(self)
175 def set_resources(self):
176 disk_max = self.rspec['disk_max']
177 logger.log('%s: setting max disk usage to %d KiB' % (self.name, disk_max))
178 try: # if the sliver is over quota, .set_disk_limit will throw an exception
179 if not self.disk_usage_initialized:
180 self.vm_running = False
181 logger.log('%s: computing disk usage: beginning' % self.name)
182 Sliver_VS._init_disk_info_sem.acquire()
183 try: self.init_disk_info()
184 finally: Sliver_VS._init_disk_info_sem.release()
185 logger.log('%s: computing disk usage: ended' % self.name)
186 self.disk_usage_initialized = True
187 vserver.VServer.set_disklimit(self, max(disk_max, self.disk_blocks))
189 logger.log('%s: failed to set max disk usage' % self.name)
190 logger.log_exc(self.name)
192 # get/set the min/soft/hard values for all of the vserver
193 # related RLIMITS. Note that vserver currently only
194 # implements support for hard limits.
195 for limit in vserver.RLIMITS.keys():
197 minimum = self.rspec['%s_min'%type]
198 soft = self.rspec['%s_soft'%type]
199 hard = self.rspec['%s_hard'%type]
200 update = self.set_rlimit(limit, hard, soft, minimum)
202 logger.log('%s: setting rlimit %s to (%d, %d, %d)'
203 % (self.name, type, hard, soft, minimum))
205 self.set_capabilities_config(self.rspec['capabilities'])
206 if self.rspec['capabilities']:
207 logger.log('%s: setting capabilities to %s' % (self.name, self.rspec['capabilities']))
209 cpu_pct = self.rspec['cpu_pct']
210 cpu_share = self.rspec['cpu_share']
212 if self.rspec['enabled'] > 0:
214 logger.log('%s: setting cpu reservation to %d%%' % (self.name, cpu_pct))
219 logger.log('%s: setting cpu share to %d' % (self.name, cpu_share))
223 self.set_sched_config(cpu_pct, cpu_share)
224 # if IP address isn't set (even to 0.0.0.0), sliver won't be able to use network
225 if self.rspec['ip_addresses'] != '0.0.0.0':
226 logger.log('%s: setting IP address(es) to %s' % \
227 (self.name, self.rspec['ip_addresses']))
228 self.set_ipaddresses_config(self.rspec['ip_addresses'])
230 if self.is_running():
231 logger.log("%s: Setting name to %s" % (self.name, self.slice_id),2)
232 self.setname(self.slice_id)
234 if False: # Does not work properly yet.
235 if self.have_limits_changed():
236 logger.log('%s: limits have changed --- restarting' % self.name)
238 while self.is_running() and stopcount > 0:
242 stopcount = stopcount - 1
245 else: # tell vsh to disable remote login by setting CPULIMIT to 0
246 logger.log('%s: disabling remote login' % self.name)
247 self.set_sched_config(0, 0)