#!/usr/bin/env python
#
# Executes the given command and returns the captured output.
#
# Author: Frank Steggink
#
import subprocess
import os
from stetl.component import Config
from stetl.filter import Filter
from stetl.util import Util
from stetl.packet import FORMAT
log = Util.get_log('execfilter')
[docs]class ExecFilter(Filter):
"""
Executes any command (abstract base class).
"""
[docs] @Config(ptype=str, default='', required=False)
def env_args(self):
"""
Provides of list of environment variables which will be used when executing the given command.
Example: env_args = pgpassword=postgres othersetting=value~with~spaces
"""
pass
[docs] @Config(ptype=str, default='=', required=False)
def env_separator(self):
"""
Provides the separator to split the environment variable names from their values.
"""
pass
def __init__(self, configdict, section, consumes, produces):
Filter.__init__(self, configdict, section, consumes, produces)
[docs] def invoke(self, packet):
return packet
def execute_cmd(self, cmd):
env_vars = Util.string_to_dict(self.env_args, self.env_separator)
old_environ = os.environ.copy()
try:
os.environ.update(env_vars)
log.info("executing cmd=%s" % cmd)
result = subprocess.check_output(cmd, shell=True)
log.info("execute done")
return result
finally:
os.environ = old_environ
[docs]class CommandExecFilter(ExecFilter):
"""
Executes an arbitrary command and captures the output
consumes=FORMAT.string, produces=FORMAT.string
"""
def __init__(self, configdict, section):
ExecFilter.__init__(self, configdict, section, consumes=FORMAT.string, produces=FORMAT.string)
[docs] def invoke(self, packet):
if packet.data is not None:
packet.data = self.execute_cmd(packet.data)
return packet