4 Functionality common to all account classes.
6 Each subclass of Account must provide five methods:
7 (*) create() and destroy(), which are static;
8 (*) configure(), start(), and stop(), which are not.
10 configure(), which takes a record as its only argument, does
11 things like set up ssh keys. In addition, an Account subclass must
12 provide static member variables SHELL, which contains the unique shell
13 that it uses; and TYPE, a string that is used by the account creation
14 code. For no particular reason, TYPE is divided hierarchically by
15 periods; at the moment the only convention is that all sliver accounts
16 have type that begins with sliver.
18 There are any number of race conditions that may result from the fact
19 that account names are not unique over time. Moreover, it's a bad
20 idea to perform lengthy operations while holding the database lock.
21 In order to deal with both of these problems, we use a worker thread
22 for each account name that ever exists. On 32-bit systems with large
23 numbers of accounts, this may cause the NM process to run out of
24 *virtual* memory! This problem may be remedied by decreasing the
37 # shell path -> account class association
39 # account type -> account class association
42 # these semaphores are acquired before creating/destroying an account
43 create_sem = threading.Semaphore(1)
44 destroy_sem = threading.Semaphore(1)
46 def register_class(acct_class):
48 Call once for each account class. This method adds the class
49 to the dictionaries used to look up account classes
52 shell_acct_class[acct_class.SHELL] = acct_class
53 type_acct_class[acct_class.TYPE] = acct_class
56 # private account name -> worker object association and associated lock
57 name_worker_lock = threading.Lock()
61 return [pw_ent for pw_ent in pwd.getpwall() if pw_ent[6] in shell_acct_class]
64 """Return the names of all accounts on the system with recognized shells."""
65 return [pw_ent[0] for pw_ent in allpwents()]
69 Return the worker object for a particular username.
70 If no such object exists, create it first.
72 name_worker_lock.acquire()
74 if name not in name_worker: name_worker[name] = Worker(name)
75 return name_worker[name]
76 finally: name_worker_lock.release()
81 Base class for all types of account
84 def __init__(self, name):
87 logger.verbose('account: Initing account %s'%name)
90 def create(name, vref = None):
97 def configure(self, rec):
99 Write <rec['keys']> to my authorized_keys file.
101 new_keys = rec['keys']
102 logger.verbose('account: configuring {} with {} keys'.format(self.name, len(new_keys)))
103 if new_keys != self.keys:
104 # get the unix account info
105 gid = grp.getgrnam("slices")[2]
106 pw_info = pwd.getpwnam(self.name)
110 # write out authorized_keys file and conditionally create
111 # the .ssh subdir if need be.
112 dot_ssh = os.path.join(pw_dir, '.ssh')
113 if not os.path.isdir(dot_ssh):
114 if not os.path.isdir(pw_dir):
115 logger.verbose('account: WARNING: homedir %s does not exist for %s!'%(pw_dir, self.name))
117 os.chown(pw_dir, uid, gid)
120 auth_keys = os.path.join(dot_ssh, 'authorized_keys')
121 tools.write_file(auth_keys, lambda f: f.write(new_keys))
123 # set access permissions and ownership properly
124 os.chmod(dot_ssh, 0700)
125 os.chown(dot_ssh, uid, gid)
126 os.chmod(auth_keys, 0600)
127 os.chown(auth_keys, uid, gid)
129 # set self.keys to new_keys only when all of the above ops succeed
132 logger.log('account: %s: installed ssh keys' % self.name)
134 def start(self, delay=0):
138 def is_running(self):
141 ### this used to be a plain method but because it needs to be invoked by destroy
142 # which is a static method, they need to become static as well
143 # needs to be done before sliver starts (checked with vs and lxc)
145 def mount_ssh_dir (slicename): return Account._manage_ssh_dir (slicename, do_mount=True)
147 def umount_ssh_dir (slicename): return Account._manage_ssh_dir (slicename, do_mount=False)
149 # bind mount / umount root side dir to sliver side
151 def _manage_ssh_dir (slicename, do_mount):
152 logger.log ("_manage_ssh_dir, requested to "+("mount" if do_mount else "umount")+" ssh dir for "+ slicename)
154 root_ssh = "/home/%s/.ssh"%slicename
155 sliver_ssh = "/vservers/%s/home/%s/.ssh"%(slicename, slicename)
156 def is_mounted (root_ssh):
157 for mount_line in file('/proc/mounts').readlines():
158 if mount_line.find (root_ssh) >= 0:
162 # any of both might not exist yet
163 for path in [root_ssh, sliver_ssh]:
164 if not os.path.exists (path):
166 if not os.path.isdir (path):
168 if not is_mounted(root_ssh):
169 command = ['mount', '--bind', '-o', 'ro', root_ssh, sliver_ssh]
170 mounted = logger.log_call (command)
171 msg = "OK" if mounted else "WARNING: FAILED"
172 logger.log("_manage_ssh_dir: mounted %s into slice %s - %s"%(root_ssh, slicename, msg))
174 if is_mounted (sliver_ssh):
175 command = ['umount', sliver_ssh]
176 umounted = logger.log_call(command)
177 msg = "OK" if umounted else "WARNING: FAILED"
178 logger.log("_manage_ssh_dir: umounted %s - %s"%(sliver_ssh, msg))
180 logger.log_exc("_manage_ssh_dir failed", name=slicename)
184 def __init__(self, name):
185 self.name = name # username
186 self._acct = None # the account object currently associated with this worker
188 def ensure_created(self, rec):
190 Check account type is still valid. If not, recreate sliver.
191 If still valid, check if running and configure/start if not.
193 logger.log_data_in_file(rec, "/var/lib/nodemanager/%s.rec.txt"%rec['name'],
194 'raw rec captured in ensure_created', logger.LOG_VERBOSE)
195 curr_class = self._get_class()
196 next_class = type_acct_class[rec['type']]
197 if next_class != curr_class:
198 self._destroy(curr_class)
200 try: next_class.create(self.name, rec)
201 finally: create_sem.release()
202 if not isinstance(self._acct, next_class): self._acct = next_class(rec)
203 logger.verbose("account.Worker.ensure_created: %s, running=%r"%(self.name, self.is_running()))
205 # reservation_alive is set on reservable nodes, and its value is a boolean
206 if 'reservation_alive' in rec:
208 if rec['reservation_alive']:
209 # this sliver has the lease, it is safe to start it
210 if not self.is_running():
212 else: self.configure(rec)
214 # not having the lease, do not start it
216 # usual nodes - preserve old code
217 # xxx it's not clear what to do when a sliver changes type/class
218 # in a reservable node
220 if not self.is_running() or next_class != curr_class:
225 def ensure_destroyed(self):
226 self._destroy(self._get_class())
228 # take rec as an arg here for api_calls
229 def start(self, rec, d = 0):
230 self._acct.configure(rec)
231 self._acct.start(delay=d)
233 def configure(self, rec):
234 self._acct.configure(rec)
239 def is_running(self):
240 if (self._acct != None) and self._acct.is_running():
244 logger.verbose("account: Worker(%s): is not running" % self.name)
247 def _destroy(self, curr_class):
250 destroy_sem.acquire()
251 try: curr_class.destroy(self.name)
252 finally: destroy_sem.release()
254 def _get_class(self):
255 try: shell = pwd.getpwnam(self.name)[6]
256 except KeyError: return None
257 return shell_acct_class[shell]