periods; at the moment the only convention is that all sliver accounts
have type that begins with sliver.
-There are any number of race conditions that may result from the fact
-that account names are not unique over time. Moreover, it's a bad
-idea to perform lengthy operations while holding the database lock.
-In order to deal with both of these problems, we use a worker thread
-for each account name that ever exists. On 32-bit systems with large
-numbers of accounts, this may cause the NM process to run out of
-*virtual* memory! This problem may be remedied by decreasing the
-maximum stack size.
"""
import Queue
import os
import pwd
+from grp import getgrnam
import threading
import logger
import tools
+# When this variable is true, start after any ensure_created
+Startingup = False
# shell path -> account class association
shell_acct_class = {}
# account type -> account class association
type_acct_class = {}
+# these semaphores are acquired before creating/destroying an account
+create_sem = threading.Semaphore(1)
+destroy_sem = threading.Semaphore(1)
+
def register_class(acct_class):
"""Call once for each account class. This method adds the class to the dictionaries used to look up account classes by shell and type."""
shell_acct_class[acct_class.SHELL] = acct_class
# private account name -> worker object association and associated lock
name_worker_lock = threading.Lock()
+# dict of account_name: <Worker Object>
name_worker = {}
+def allpwents():
+ return [pw_ent for pw_ent in pwd.getpwall() if pw_ent[6] in shell_acct_class]
+
def all():
"""Return the names of all accounts on the system with recognized shells."""
- return [pw_ent[0] for pw_ent in pwd.getpwall() if pw_ent[6] in shell_acct_class]
+ return [pw_ent[0] for pw_ent in allpwents()]
def get(name):
"""Return the worker object for a particular username. If no such object exists, create it first."""
name_worker_lock.acquire()
try:
- if name not in name_worker: name_worker[name] = Worker(name)
+ if name not in name_worker:
+ logger.verbose("Accounts:get(%s) new Worker" % name)
+ name_worker[name] = Worker(name)
return name_worker[name]
finally: name_worker_lock.release()
class Account:
def __init__(self, rec):
+ logger.verbose('Initing account %s'%rec['name'])
self.name = rec['name']
self.keys = ''
+ self.initscriptchanged = False
self.configure(rec)
@staticmethod
- def create(name): abstract
+ def create(name, vref = None): abstract
@staticmethod
def destroy(name): abstract
def configure(self, rec):
"""Write <rec['keys']> to my authorized_keys file."""
+ logger.verbose('%s: in accounts:configure'%self.name)
new_keys = rec['keys']
if new_keys != self.keys:
self.keys = new_keys
dot_ssh = '/home/%s/.ssh' % self.name
- def do_installation():
- if not os.access(dot_ssh, os.F_OK): os.mkdir(dot_ssh)
- tools.write_file(dot_ssh + '/authorized_keys', lambda f: f.write(new_keys))
+ if not os.access(dot_ssh, os.F_OK): os.mkdir(dot_ssh)
+ os.chmod(dot_ssh, 0700)
+ tools.write_file(dot_ssh + '/authorized_keys', lambda f: f.write(new_keys))
logger.log('%s: installing ssh keys' % self.name)
- tools.fork_as(self.name, do_installation)
+ user = pwd.getpwnam(self.name)[2]
+ group = getgrnam("slices")[2]
+ os.chown(dot_ssh, user, group)
+ os.chown(dot_ssh + '/authorized_keys', user, group)
def start(self, delay=0): pass
def stop(self): pass
-
+ def is_running(self): pass
class Worker:
- # these semaphores are acquired before creating/destroying an account
- _create_sem = threading.Semaphore(1)
- _destroy_sem = threading.Semaphore(1)
-
def __init__(self, name):
self.name = name # username
self._acct = None # the account object currently associated with this worker
- # task list
- # outsiders request operations by putting (fn, args...) tuples on _q
- # the worker thread (created below) will perform these operations in order
- self._q = Queue.Queue()
- tools.as_daemon_thread(self._run)
- def ensure_created(self, rec):
- """Cause the account specified by <rec> to exist if it doesn't already."""
- self._q.put((self._ensure_created, rec.copy()))
-
- def _ensure_created(self, rec):
+ def ensure_created(self, rec, startingup = Startingup):
+ """Check account type is still valid. If not, recreate sliver. If still valid,
+ check if running and configure/start if not."""
curr_class = self._get_class()
next_class = type_acct_class[rec['type']]
if next_class != curr_class:
self._destroy(curr_class)
- self._create_sem.acquire()
- try: next_class.create(self.name)
- finally: self._create_sem.release()
+ create_sem.acquire()
+ try: next_class.create(self.name, rec['vref'])
+ finally: create_sem.release()
if not isinstance(self._acct, next_class): self._acct = next_class(rec)
+ if startingup or \
+ not self.is_running() or \
+ next_class != curr_class or \
+ self._acct.initscriptchanged:
+ self.start(rec)
else: self._acct.configure(rec)
- if next_class != curr_class: self._acct.start()
- def ensure_destroyed(self): self._q.put((self._ensure_destroyed,))
- def _ensure_destroyed(self): self._destroy(self._get_class())
+ def ensure_destroyed(self): self._destroy(self._get_class())
+
+ def start(self, rec, d = 0):
+ self._acct.configure(rec)
+ self._acct.start(delay=d)
- def start(self, delay=0): self._q.put((self._start, delay))
- def _start(self, d): self._acct.start(delay=d)
+ def stop(self): self._acct.stop()
- def stop(self): self._q.put((self._stop,))
- def _stop(self): self._acct.stop()
+ def is_running(self):
+ if self._acct.is_running():
+ status = True
+ else:
+ status = False
+ logger.verbose("Worker(%s): is not running" % self.name)
+ return status
def _destroy(self, curr_class):
self._acct = None
if curr_class:
- self._destroy_sem.acquire()
+ destroy_sem.acquire()
try: curr_class.destroy(self.name)
- finally: self._destroy_sem.release()
+ finally: destroy_sem.release()
def _get_class(self):
try: shell = pwd.getpwnam(self.name)[6]
except KeyError: return None
return shell_acct_class[shell]
-
- def _run(self):
- """Repeatedly pull commands off the queue and execute. If memory usage becomes an issue, it might be wise to terminate after a while."""
- while True:
- try:
- cmd = self._q.get()
- cmd[0](*cmd[1:])
- except: logger.log_exc()