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