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) or
110 os.path.isdir ("/vservers/.vref/%s"% vref)):
111 logger.verbose("%s (%s) : vref %s not found, using default %s"%(
112 name,vref,refname,default))
114 # could check again, but as we have /etc/slicefamily
115 # there's probably no /vservers/.vref/default
118 # have not found slicefamily
119 logger.verbose("%s (%s): legacy node - using fallback vrefname 'default'"%(name,vref))
124 logger.log("%s (%s) : unexpected error follows - using 'default'"%(
126 logger.log(traceback.format_exc())
129 logger.log_call('/usr/sbin/vuseradd', '-t', refname, name)
130 open('/vservers/%s/etc/slicename' % name, 'w').write(name)
133 def destroy(name): logger.log_call('/usr/sbin/vuserdel', name)
135 def configure(self, rec):
136 new_rspec = rec['_rspec']
137 if new_rspec != self.rspec:
138 self.rspec = new_rspec
141 new_initscript = rec['initscript']
142 if new_initscript != self.initscript:
143 self.initscript = new_initscript
144 logger.log('%s: installing initscript' % self.name)
145 def install_initscript():
146 flags = os.O_WRONLY | os.O_CREAT | os.O_TRUNC
147 fd = os.open('/etc/rc.vinit', flags, 0755)
148 os.write(fd, new_initscript)
151 self.chroot_call(install_initscript)
152 self.initscriptchanged = True
153 except: logger.log_exc(self.name)
155 accounts.Account.configure(self, rec) # install ssh keys
157 def start(self, delay=0):
158 if self.rspec['enabled'] > 0:
159 logger.log('%s: starting in %d seconds' % (self.name, delay))
161 child_pid = os.fork()
163 # VServer.start calls fork() internally,
164 # so just close the nonstandard fds and fork once to avoid creating zombies
165 tools.close_nonstandard_fds()
166 vserver.VServer.start(self)
168 else: os.waitpid(child_pid, 0)
169 else: logger.log('%s: not starting, is not enabled' % self.name)
170 self.initscriptchanged = False
173 logger.log('%s: stopping' % self.name)
174 vserver.VServer.stop(self)
176 def set_resources(self):
177 disk_max = self.rspec['disk_max']
178 logger.log('%s: setting max disk usage to %d KiB' % (self.name, disk_max))
179 try: # if the sliver is over quota, .set_disk_limit will throw an exception
180 if not self.disk_usage_initialized:
181 self.vm_running = False
182 logger.log('%s: computing disk usage: beginning' % self.name)
183 Sliver_VS._init_disk_info_sem.acquire()
184 try: self.init_disk_info()
185 finally: Sliver_VS._init_disk_info_sem.release()
186 logger.log('%s: computing disk usage: ended' % self.name)
187 self.disk_usage_initialized = True
188 vserver.VServer.set_disklimit(self, max(disk_max, self.disk_blocks))
190 logger.log('%s: failed to set max disk usage' % self.name)
191 logger.log_exc(self.name)
193 # get/set the min/soft/hard values for all of the vserver
194 # related RLIMITS. Note that vserver currently only
195 # implements support for hard limits.
196 for limit in vserver.RLIMITS.keys():
198 minimum = self.rspec['%s_min'%type]
199 soft = self.rspec['%s_soft'%type]
200 hard = self.rspec['%s_hard'%type]
201 update = self.set_rlimit(limit, hard, soft, minimum)
203 logger.log('%s: setting rlimit %s to (%d, %d, %d)'
204 % (self.name, type, hard, soft, minimum))
206 self.set_capabilities_config(self.rspec['capabilities'])
207 if self.rspec['capabilities']:
208 logger.log('%s: setting capabilities to %s' % (self.name, self.rspec['capabilities']))
210 cpu_pct = self.rspec['cpu_pct']
211 cpu_share = self.rspec['cpu_share']
213 if self.rspec['enabled'] > 0:
215 logger.log('%s: setting cpu reservation to %d%%' % (self.name, cpu_pct))
220 logger.log('%s: setting cpu share to %d' % (self.name, cpu_share))
224 self.set_sched_config(cpu_pct, cpu_share)
225 # if IP address isn't set (even to 0.0.0.0), sliver won't be able to use network
226 if self.rspec['ip_addresses'] != '0.0.0.0':
227 logger.log('%s: setting IP address(es) to %s' % \
228 (self.name, self.rspec['ip_addresses']))
229 self.set_ipaddresses_config(self.rspec['ip_addresses'])
231 if self.is_running():
232 logger.log("%s: Setting name to %s" % (self.name, self.slice_id),2)
233 self.setname(self.slice_id)
235 if False: # Does not work properly yet.
236 if self.have_limits_changed():
237 logger.log('%s: limits have changed --- restarting' % self.name)
239 while self.is_running() and stopcount > 0:
243 stopcount = stopcount - 1
246 else: # tell vsh to disable remote login by setting CPULIMIT to 0
247 logger.log('%s: disabling remote login' % self.name)
248 self.set_sched_config(0, 0)