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 {}'.format(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 {} does not exist for {}!'
116 .format(pw_dir, self.name))
118 os.chown(pw_dir, uid, gid)
121 auth_keys = os.path.join(dot_ssh, 'authorized_keys')
122 tools.write_file(auth_keys, lambda f: f.write(new_keys))
124 # set access permissions and ownership properly
125 os.chmod(dot_ssh, 0700)
126 os.chown(dot_ssh, uid, gid)
127 os.chmod(auth_keys, 0600)
128 os.chown(auth_keys, uid, gid)
130 # set self.keys to new_keys only when all of the above ops succeed
133 logger.log('account: {}: installed ssh keys'.format(self.name))
135 def start(self, delay=0):
139 def is_running(self):
142 ### this used to be a plain method but because it needs to be invoked by destroy
143 # which is a static method, they need to become static as well
144 # needs to be done before sliver starts (checked with vs and lxc)
146 def mount_ssh_dir (slicename): return Account._manage_ssh_dir (slicename, do_mount=True)
148 def umount_ssh_dir (slicename): return Account._manage_ssh_dir (slicename, do_mount=False)
150 # bind mount / umount root side dir to sliver side
152 def _manage_ssh_dir (slicename, do_mount):
153 logger.log ("_manage_ssh_dir, requested to "+("mount" if do_mount else "umount")+" ssh dir for "+ slicename)
155 root_ssh = "/home/{}/.ssh".format(slicename)
156 sliver_ssh = "/vservers/{}/home/{}/.ssh".format(slicename, slicename)
157 def is_mounted (root_ssh):
158 with open('/proc/mounts') as mountsfile:
159 for mount_line in mountsfile.readlines():
160 if mount_line.find (root_ssh) >= 0:
164 # any of both might not exist yet
165 for path in [root_ssh, sliver_ssh]:
166 if not os.path.exists (path):
168 if not os.path.isdir (path):
170 if not is_mounted(root_ssh):
171 command = ['mount', '--bind', '-o', 'ro', root_ssh, sliver_ssh]
172 mounted = logger.log_call (command)
173 msg = "OK" if mounted else "WARNING: FAILED"
174 logger.log("_manage_ssh_dir: mounted {} into slice {} - {}"
175 .format(root_ssh, slicename, msg))
177 if is_mounted (sliver_ssh):
178 command = ['umount', sliver_ssh]
179 umounted = logger.log_call(command)
180 msg = "OK" if umounted else "WARNING: FAILED"
181 logger.log("_manage_ssh_dir: umounted {} - {}"
182 .format(sliver_ssh, msg))
184 logger.log_exc("_manage_ssh_dir failed", name=slicename)
188 def __init__(self, name):
189 self.name = name # username
190 self._acct = None # the account object currently associated with this worker
192 def ensure_created(self, rec):
194 Check account type is still valid. If not, recreate sliver.
195 If still valid, check if running and configure/start if not.
197 logger.log_data_in_file(rec, "/var/lib/nodemanager/{}.rec.txt".format(rec['name']),
198 'raw rec captured in ensure_created', logger.LOG_VERBOSE)
199 curr_class = self._get_class()
200 next_class = type_acct_class[rec['type']]
201 if next_class != curr_class:
202 self._destroy(curr_class)
204 try: next_class.create(self.name, rec)
205 finally: create_sem.release()
206 if not isinstance(self._acct, next_class):
207 self._acct = next_class(rec)
208 logger.verbose("account.Worker.ensure_created: {}, running={}"
209 .format(self.name, self.is_running()))
211 # reservation_alive is set on reservable nodes, and its value is a boolean
212 if 'reservation_alive' in rec:
214 if rec['reservation_alive']:
215 # this sliver has the lease, it is safe to start it
216 if not self.is_running():
218 else: self.configure(rec)
220 # not having the lease, do not start it
222 # usual nodes - preserve old code
223 # xxx it's not clear what to do when a sliver changes type/class
224 # in a reservable node
226 if not self.is_running() or next_class != curr_class:
231 def ensure_destroyed(self):
232 self._destroy(self._get_class())
234 # take rec as an arg here for api_calls
235 def start(self, rec, d = 0):
236 self._acct.configure(rec)
237 self._acct.start(delay=d)
239 def configure(self, rec):
240 self._acct.configure(rec)
245 def is_running(self):
246 if (self._acct != None) and self._acct.is_running():
250 logger.verbose("account: Worker({}): is not running".format(self.name))
253 def _destroy(self, curr_class):
256 destroy_sem.acquire()
257 try: curr_class.destroy(self.name)
258 finally: destroy_sem.release()
260 def _get_class(self):
261 try: shell = pwd.getpwnam(self.name)[6]
262 except KeyError: return None
263 return shell_acct_class[shell]