services/nodemanager/arvnodeman/computenode/__init__.py

   1 #!/usr/bin/env python
   2
   3 from __future__ import absolute_import, print_function
   4
   5 import itertools
   6 import time
   7
   8 ARVADOS_TIMEFMT = '%Y-%m-%dT%H:%M:%SZ'
   9
  10 def arvados_node_fqdn(arvados_node, default_hostname='dynamic.compute'):
  11     hostname = arvados_node.get('hostname') or default_hostname
  12     return '{}.{}'.format(hostname, arvados_node['domain'])
  13
  14 def arvados_node_mtime(node):
  15     return arvados_timestamp(node['modified_at'])
  16
  17 def arvados_timestamp(timestr):
  18     return time.mktime(time.strptime(timestr + 'UTC',
  19                                      ARVADOS_TIMEFMT + '%Z')) - time.timezone
  20
  21 def timestamp_fresh(timestamp, fresh_time):
  22     return (time.time() - timestamp) < fresh_time
  23
  24 class ShutdownTimer(object):
  25     """Keep track of a cloud node's shutdown windows.
  26
  27     Instantiate this class with a timestamp of when a cloud node started,
  28     and a list of durations (in minutes) of when the node must not and may
  29     be shut down, alternating.  The class will tell you when a shutdown
  30     window is open, and when the next open window will start.
  31     """
  32     def __init__(self, start_time, shutdown_windows):
  33         # The implementation is easiest if we have an even number of windows,
  34         # because then windows always alternate between open and closed.
  35         # Rig that up: calculate the first shutdown window based on what's
  36         # passed in.  Then, if we were given an odd number of windows, merge
  37         # that first window into the last one, since they both# represent
  38         # closed state.
  39         first_window = shutdown_windows[0]
  40         shutdown_windows = list(shutdown_windows[1:])
  41         self._next_opening = start_time + (60 * first_window)
  42         if len(shutdown_windows) % 2:
  43             shutdown_windows.append(first_window)
  44         else:
  45             shutdown_windows[-1] += first_window
  46         self.shutdown_windows = itertools.cycle([60 * n
  47                                                  for n in shutdown_windows])
  48         self._open_start = self._next_opening
  49         self._open_for = next(self.shutdown_windows)
  50
  51     def _advance_opening(self):
  52         while self._next_opening < time.time():
  53             self._open_start = self._next_opening
  54             self._next_opening += self._open_for + next(self.shutdown_windows)
  55             self._open_for = next(self.shutdown_windows)
  56
  57     def next_opening(self):
  58         self._advance_opening()
  59         return self._next_opening
  60
  61     def window_open(self):
  62         self._advance_opening()
  63         return 0 < (time.time() - self._open_start) < self._open_for