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fence_powerman.py
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#!@PYTHON@ -tt
import os
import time
from datetime import datetime
import sys
import subprocess
import re
import atexit
sys.path.append("@FENCEAGENTSLIBDIR@")
from fencing import *
from fencing import is_executable, fail_usage, run_delay
import logging
#### important!!! #######
class PowerMan:
"""Python wrapper for calling powerman commands
This class makes calls to a powerman deamon for a cluster of computers.
The make-up of such a call looks something like:
$ pm -h elssd1:10101 <option> <node>
where option is something like --off, --on, --cycle and where node is
elssd8, or whatever values are setup in powerman.conf. Note that powerman
itself must be configured for this fence agent to work.
"""
def __init__(self, powerman_path, server_name, port):
"""
Args:
server_name: (string) host or ip of powerman server
port: (str) port number that the powerman server is listening on
"""
self.powerman_path = powerman_path
self.server_name = server_name
self.port = port
self.server_and_port = server_name + ":" + str(port)
self.base_cmd = [
self.powerman_path,
"--server-host",
self.server_and_port
]
def _run(self, cmd, only_first_line):
# Args:
# cmd: (list) commands and arguments to pass to the program_name
run_this = self.base_cmd + cmd
try:
popen = subprocess.Popen(run_this, stdin=subprocess.PIPE, stdout=subprocess.PIPE)
out = popen.communicate()
except OSError as e:
logging.error("_run command error: %s\n", e)
sys.exit(1)
if only_first_line == True:
result_line = out[0].decode().strip()
return (result_line, popen.returncode)
else:
result_list = []
for line in out:
result_list.append(line)
return (result_list, popen.returncode)
def is_running(self):
"""simple query to see if powerman server is responding. Returns boolean"""
cmd = ["-q"] # just check if we get a response from the server
result, ret_code = self._run(cmd, True)
if ret_code != 0:
return False
return True
## Some devices respond to on or off actions as if the action was successful,
## when it was not.
##
## This is not unique to powerman, and so fence_action ignores the return code
## from the set_power_fn and queries the device to confirm the power status of
## the machine.
##
## For this reason we do not do a query ourself, retry, etc. in on() or off().
def on(self, host):
logging.debug("PowerMan on: %s\n", host)
cmd = ["--on", host]
try:
result, ret_code = self._run(cmd, True)
except OSError as e:
logging.error("PowerMan Error: The command '--on' failed: %s\n", e)
return -1
except ValueError as e:
logging.error("PowerMan Error: Popen: invalid arguments: %s\n", e)
return -1
logging.debug("pm.on result: %s ret_code: %s\n", result, ret_code)
return ret_code
def off(self, host):
logging.debug("PowerMan off: %s\n", host)
cmd = ["--off", host]
try:
result, ret_code = self._run(cmd, True)
except OSError as e:
logging.error("PowerMan Error: The command '%s' failed: %s\n", cmd, e)
return -1
except ValueError as e:
logging.error("PowerMan Error: Popen: invalid arguments: %s\n", e)
return -1
logging.debug("pm.off result: %s ret_code: %s\n", result, ret_code)
return ret_code
def list(self):
## Error checking here is faulty. Try passing
## invalid args, e.g. --query --exprange to see failure
cmd = ["-q","--exprange"]
try:
result, ret_code = self._run(cmd, False)
except OSError as e:
logging.error("PowerMan Error: The command '%s' failed: %s\n", cmd, e)
return -1
except ValueError as e:
logging.error("PowerMan Error: Popen: invalid arguments: %s\n", e)
return -1
if ret_code < 0:
# there was an error with the command
return ret_code
else:
state = {}
for line in result[0].split('\n'):
if len(line) > 2:
fields = line.split(':')
if len(fields) == 2:
state[fields[0]] = (fields[0],fields[1])
return state
def query(self, host):
cmd = ["--query", host]
try:
result, ret_code = self._run(cmd, True)
except OSError as e:
logging.error("PowerMan Error: The command '%s' failed: %s\n", cmd, e)
return -1
except ValueError as e:
logging.error("PowerMan Error: Popen: invalid arguments: %s\n", e)
return -1
if ret_code < 0:
# there was an error with the command
return ret_code
else:
res = result.split('\n')
res = [r.split() for r in res]
# find the host in command's returned output
for lst in res:
if lst[0] == 'No' and lst[1] == 'such' and lst[2] == 'nodes:':
return -1
if host in lst:
return lst[0][:-1] # lst[0] would be 'off:'-- this removes the colon
# host isn't in the output
return -1
def get_power_status(conn, options):
logging.debug("get_power_status function:\noptions: %s\n", str(options))
pm = PowerMan(options['--powerman-path'], options['--ip'], options['--ipport'])
# if Pacemaker is checking the status of the Powerman server...
if options['--action'] == 'monitor':
if pm.is_running():
logging.debug("Powerman is running\n")
return "on"
logging.debug("Powerman is NOT running\n")
return "error"
else:
status = pm.query(options['--plug'])
if isinstance(int, type(status)):
# query only returns ints on error
logging.error("get_power_status: query returned %s\n", str(status))
fail(EC_STATUS)
return status
def set_power_status(conn, options):
logging.debug("set_power_status function:\noptions: %s", str(options))
pm = PowerMan(options['--powerman-path'], options['--ip'], options['--ipport'])
action = options["--action"]
if action == "on":
pm.on(options['--plug'])
elif action == "off":
pm.off(options['--plug'])
return
def get_list(conn, options):
logging.debug("get_list function:\noptions: %s", str(options))
pm = PowerMan(options['--powerman-path'], options['--ip'], options['--ipport'])
outlets = pm.list()
logging.debug("get_list outlets.keys: %s", str(outlets.keys()))
return outlets
def define_new_opts():
all_opt["powerman_path"] = {
"getopt" : ":",
"longopt" : "powerman-path",
"help" : "--powerman-path=[path] Path to powerman binary",
"required" : "0",
"shortdesc" : "Path to powerman binary",
"default" : "@POWERMAN_PATH@",
"order": 200
}
def main():
device_opt = [
'ipaddr',
'no_password',
'no_login',
'powerman_path',
]
atexit.register(atexit_handler)
define_new_opts()
# redefine default values for the options given by fencing.py
# these 3 different values are derived from the lssd test cluster and may
# need to adjusted depending on how other systems fare
all_opt['ipport']['default'] = '10101'
all_opt['delay']['default'] = '3'
all_opt['power_wait']['default'] = '3'
options = check_input(device_opt, process_input(device_opt))
docs = {}
docs["shortdesc"] = "Fence Agent for Powerman"
docs["longdesc"] = "This is a Pacemaker Fence Agent for the \
Powerman management utility that was designed for LLNL systems."
docs["vendorurl"] = "https://github.com/chaos/powerman"
show_docs(options, docs)
run_delay(options)
if not is_executable(options["--powerman-path"]):
fail_usage("Powerman not found or not executable at path " + options["--powerman-path"])
# call the fencing.fence_action function, passing in my various fence functions
result = fence_action(
None,
options,
set_power_status,
get_power_status,
get_list,
None
)
sys.exit(result)
if __name__ == "__main__":
main()

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