[pycopia] r527 committed - Added shutdown detector.

[pyc...@googlecode.com]

Revision: 527
Author: keith.dart
Date: Tue Jan 24 00:23:14 2012
Log: Added shutdown detector.

http://code.google.com/p/pycopia/source/detail?r=527

Modified:
/trunk/net/pycopia/ping.py

=======================================
--- /trunk/net/pycopia/ping.py Tue Jan 10 22:35:22 2012
+++ /trunk/net/pycopia/ping.py Tue Jan 24 00:23:14 2012
@@ -205,10 +205,12 @@
2. Loop until target is not pingable.
3. While target is not pingable, loop until it is pingable again.

- The target must have recently initiated a reboot before this is
called, and
- still be pingable. Timing is important here.
-
- Call the `go` method when you are ready to go.
+ The target may have recently initiated a reboot before this is called,
and
+ still be pingable. Timing is important in this case.
+
+ Call the `go` method when you are ready to go. You may supply an
optional
+ callback that will be called after the target is determined to be
+ reachable. This may initiate the actual reboot.

May raise RebootDetectorError at any phase.
"""
@@ -224,7 +226,7 @@
def __del__(self):
self._pinger.kill()

- def go(self):
+ def go(self, callback=None):
isreachable = False
pinger = self._pinger
state = RebootDetector.UNKNOWN
@@ -233,6 +235,8 @@
host, isreachable = pinger.reachable(self._target)[0]
if isreachable:
state = RebootDetector.REACHABLE
+ if callback is not None:
+ callback()
else:
raise RebootDetectorError("Could not reach host
initially.")
elif state == RebootDetector.REACHABLE:
@@ -265,3 +269,52 @@
except RebootDetectorError:
return False

+
+class PoweroffDetector(object):
+ """Detect a power off of a remote device using "ping".
+
+ The following algorithm is used.
+ 1. Verify the target is pingable.
+ 2. Call a callback method that may initiate a power off.
+ 2. Loop until target is not pingable.
+
+ Call the `go` method when you are ready to go. You may supply an
optional
+ callback that will be called after the target is determined to be
+ reachable. This may initiate the actual reboot.
+
+ May raise RebootDetectorError at any phase.
+ """
+ UNKNOWN = 0
+ REACHABLE = 1
+
+ def __init__(self, target, retries=30, timeout=5, delay=10, size=64,
hops=30):
+ self._target = target
+ self._pinger = get_pinger(retries, timeout, delay, size, hops)
+
+ def __del__(self):
+ self._pinger.kill()
+
+ def go(self, callback=None):
+ isreachable = False
+ pinger = self._pinger
+ state = PoweroffDetector.UNKNOWN
+ while True:
+ if state == PoweroffDetector.UNKNOWN:
+ host, isreachable = pinger.reachable(self._target)[0]
+ if isreachable:
+ state = PoweroffDetector.REACHABLE
+ if callback is not None:
+ callback()
+ else:
+ raise RebootDetectorError("Could not reach host
initially.")
+ elif state == PoweroffDetector.REACHABLE:
+ r_retries = pinger.retries
+ while isreachable:
+ host, isreachable = pinger.reachable(self._target)[0]
+ scheduler.sleep(pinger.delay)
+ r_retries -= 1
+ if r_retries == 0:
+ raise RebootDetectorError("Target did not become
unreachable in time.")
+ else:
+ return True
+