+"""Functionality common to all account classes.
+
+Each account class must provide five methods: create(), destroy(),
+configure(), start(), and stop(). In addition, it must provide static
+member variables SHELL, which contains the unique shell that it uses;
+and TYPE, which contains a description of the type that it uses. TYPE
+is divided hierarchically by periods; at the moment the only
+convention is that all sliver accounts have type that begins with
+sliver.
+
+Because Python does dynamic method lookup, we do not bother with a
+boilerplate abstract superclass.
+
+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
type_acct_class = {}
def register_class(acct_class):
- """Call once for each account class. This method adds the class to the dictionaries used to ook up account classes by shell and type."""
+ """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
type_acct_class[acct_class.TYPE] = acct_class
_name_worker = {}
def all():
- """Returns a list of all NM accounts on the system. Format is (type, username)."""
- pw_ents = pwd.getpwall()
- for pw_ent in pw_ents:
- if pw_ent[6] in shell_acct_class:
- yield shell_acct_class[pw_ent[6]].TYPE, pw_ent[0]
+ """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]
def get(name):
"""Return the worker object for a particular username. If no such object exists, create it first."""
finally: _name_worker_lock.release()
-def install_ssh_keys(rec):
- """Write <rec['ssh_keys']> to <rec['name']>'s authorized_keys file."""
- dot_ssh = '/home/%s/.ssh' % rec['name']
+def install_keys(rec):
+ """Write <rec['keys']> to <rec['name']>'s authorized_keys file."""
+ name = rec['name']
+ dot_ssh = '/home/%s/.ssh' % 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 thefile: thefile.write(rec['ssh_keys']))
- logger.log('%s: installing ssh keys' % rec['name'])
- tools.fork_as(rec['name'], do_installation)
+ tools.write_file(dot_ssh + '/authorized_keys', lambda thefile: thefile.write(rec['keys']))
+ logger.log('%s: installing ssh keys' % name)
+ tools.fork_as(name, do_installation)
class Worker:
_destroy_sem = threading.Semaphore(1)
def __init__(self, name):
- # username
- self.name = name
- # the account object currently associated with this worker
- self._acct = None
+ 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
tools.as_daemon_thread(self._run)
def ensure_created(self, rec):
- """Caused the account specified by <rec> to exist if it doesn't already."""
- self._q.put((self._ensure_created, tools.deepcopy(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):
curr_class = self._get_class()
def _make_acct_obj(self):
curr_class = self._get_class()
- if not isinstance(self._acct, curr_class):
- self._acct = curr_class(self.name)
+ if not isinstance(self._acct, curr_class): self._acct = curr_class(self.name)
def _run(self):
while True:
git://git.onelab.eu / nodemanager.git / blobdiff