Add power management script for the IP 9258.

1 files changed, 133 insertions, 0 deletions

diff --git a/powermanager.py b/powermanager.py
new file mode 100755
index 0000000..89aad80
--- /dev/null
+++ b/powermanager.py
@@ -0,0 +1,133 @@
+#!/usr/bin/env python
+
+from __future__ import print_function
+
+import sys
+import argparse
+import os.path
+import urllib2
+
+from operator import methodcaller
+from time import sleep
+
+
+"""Manages the power for the IP Power 9258.
+
+You are meant to create symlinks to this file for each port.
+
+"""
+
+class PowerManagerException(RuntimeError):
+    def __init__(self, reason):
+        super(PowerManagerException, self).__init__()
+        self.reason = reason
+
+class PowerManager(object):
+    """Manages the power for a single port of the IP Power 9258."""
+
+    def __init__(self, host, username, password, port):
+        self.host = host
+        self.username = username
+        self.password = password
+        self.port = port
+
+    def __call_url(self, port_value):
+        port_state = '{}={}'.format(self.port, port_value)
+        full_url = 'http://{}/Set.cmd?CMD=SetPower+{}'.format(self.host,
+                port_state)
+        basic_handler = urllib2.HTTPBasicAuthHandler()
+        basic_handler.add_password(realm='IP9258',
+                uri='http://{}/'.format(self.host),
+                user=self.username,
+                passwd=self.password)
+        opener = urllib2.build_opener(basic_handler)
+        urllib2.install_opener(opener)
+        try:
+            url_res = urllib2.urlopen(full_url)
+            txt = url_res.read()
+            if -1 == txt.find(port_state):
+                """Response should be the port_state we wanted, plus HTML."""
+                raise PowerManagerException('Bad response: {}'.format(txt))
+        except urllib2.URLError as e:
+            raise PowerManagerException('Error opening URL: {}'.format(
+                e.reason))
+
+    def power_on(self):
+        print("Power on.")
+        self.__call_url('1')
+
+    def power_off(self):
+        print("Power off.")
+        self.__call_url('0')
+
+    def power_cycle(self):
+        self.power_off()
+        sleep(1)
+        self.power_on()
+
+    @classmethod
+    def dispatch_action(cls, power_manager, action):
+        ACTION_CALLBACKS = {'on': methodcaller('power_on'),
+                'off': methodcaller('power_off'),
+                'cycle': methodcaller('power_cycle')}
+        actions = ACTION_CALLBACKS.keys()
+        try:
+            action_method = ACTION_CALLBACKS[action]
+        except KeyError:
+            raise ValueError('Invalid action: {}'.format(action))
+        action_method(power_manager)
+
+
+def parse_args():
+    p = argparse.ArgumentParser(description='Control power.')
+    p.add_argument('action', help='on|off|cycle')
+    return p.parse_args(sys.argv[1:])
+
+def find_port():
+    """Finds port to use based on script name.
+    
+    Assumes the script is named <SOMETHING>-power.py, where the part before the
+    dash is a dict key.
+    
+    """
+    POWER_PORTS = { 'pound': 'P60', 'pandaboard': 'P61' }
+
+    script_name = os.path.basename(sys.argv[0])
+    dash_pos = script_name.find('-')
+    if -1 == dash_pos:
+        raise ValueError('No dash found in script name: {}'.format(script_name))
+    port_key = script_name[:dash_pos]
+    try:
+        return POWER_PORTS[port_key]
+    except KeyError:
+        raise KeyError('Port key not found in dict: {}'.format(port_key))
+
+def read_password():
+    fname = os.path.expanduser('~/.poundpower')
+    with open(fname) as f:
+        password = f.read().strip()
+    return password
+
+def main():
+    HOST = 'pound-pwr.cs.unc.edu'
+    USERNAME = 'admin'
+
+    try:
+        password = read_password()
+    except IOError as e:
+        print('Error reading password file: {}'.format(e), file=sys.stderr)
+        sys.exit(1)
+
+    args = parse_args()
+
+    port = find_port()
+    mgr = PowerManager(HOST, USERNAME, password, port)
+    try:
+        PowerManager.dispatch_action(mgr, args.action)
+    except PowerManagerException as e:
+        print('Exception: {}'.format(e.reason), file=sys.stderr)
+        sys.exit(1)
+    sys.exit(0)
+
+if __name__ == '__main__':
+    main()