ansible/lib/ansible/__init__.py

# Copyright (c) 2012 Michael DeHaan <michael.dehaan@gmail.com>
#
# Permission is hereby granted, free of charge, to any person 
# obtaining a copy of this software and associated documentation 
# files (the "Software"), to deal in the Software without restriction, 
# including without limitation the rights to use, copy, modify, merge, 
# publish, distribute, sublicense, and/or sell copies of the Software, 
# and to permit persons to whom the Software is furnished to do so, 
# subject to the following conditions:
#
# The above copyright notice and this permission notice shall be 
# included in all copies or substantial portions of the Software.
# 
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, 
# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF 
# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. 
# IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR 
# ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF 
# CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION 
# WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

import fnmatch
from multiprocessing import Process, Pipe
from itertools import izip
import os
import json
import traceback
import select

# non-core 
import paramiko

DEFAULT_HOST_LIST      = '/etc/ansible/hosts'
DEFAULT_MODULE_PATH    = '/usr/share/ansible'
DEFAULT_MODULE_NAME    = 'ping'
DEFAULT_PATTERN        = '*'
DEFAULT_FORKS          = 3
DEFAULT_MODULE_ARGS    = ''
DEFAULT_TIMEOUT        = 60
DEFAULT_REMOTE_USER    = 'root'

class Pooler(object):

    # credit: http://stackoverflow.com/questions/3288595/multiprocessing-using-pool-map-on-a-function-defined-in-a-class

    @classmethod
    def spawn(cls, f):
        def fun(pipe,x):
            pipe.send(f(x))
            pipe.close()
        return fun

    @classmethod
    def parmap(cls, f, X):
        pipe=[Pipe() for x in X]
        proc=[Process(target=cls.spawn(f),args=(c,x)) for x,(p,c) in izip(X,pipe)]
        [p.start() for p in proc]
        [p.join() for p in proc]
        return [p.recv() for (p,c) in pipe]

class Runner(object):

   def __init__(self, 
       host_list=DEFAULT_HOST_LIST, 
       module_path=DEFAULT_MODULE_PATH,
       module_name=DEFAULT_MODULE_NAME, 
       module_args=DEFAULT_MODULE_ARGS, 
       forks=DEFAULT_FORKS, 
       timeout=DEFAULT_TIMEOUT, 
       pattern=DEFAULT_PATTERN,
       remote_user=DEFAULT_REMOTE_USER,
       verbose=False):
      

       '''
       Constructor.
       '''

       self.host_list   = self._parse_hosts(host_list)
       self.module_path = module_path
       self.module_name = module_name
       self.forks       = forks
       self.pattern     = pattern
       self.module_args = module_args
       self.timeout     = timeout
       self.verbose     = verbose
       self.remote_user = remote_user

   def _parse_hosts(self, host_list):
        ''' parse the host inventory file if not sent as an array '''
        if type(host_list) != list:
            host_list = os.path.expanduser(host_list)
            return file(host_list).read().split("\n")
        return host_list


   def _matches(self, host_name):
       ''' returns if a hostname is matched by the pattern '''
       if host_name == '':
           return False
       if fnmatch.fnmatch(host_name, self.pattern):
           return True
       return False

   def _connect(self, host):
       ''' obtains a paramiko connection to the host '''
       ssh = paramiko.SSHClient()
       ssh.set_missing_host_key_policy(paramiko.AutoAddPolicy())
       try:
          ssh.connect(host, username=self.remote_user,
              allow_agent=True, look_for_keys=True)
          return [ True, ssh ]
       except:
          return [ False, traceback.format_exc() ]

   def _executor(self, host):
       ''' callback executed in parallel for each host '''
       # TODO: try/catch returning none

       ok, conn = self._connect(host)
       if not ok:
           return [ host, False, conn ]

       if self.module_name != "copy":
           # transfer a module, set it executable, and run it
           outpath = self._copy_module(conn)
           self._exec_command(conn, "chmod +x %s" % outpath)
           cmd = self._command(outpath)
           result = self._exec_command(conn, cmd)
           conn.close()
           return [ host, True, json.loads(result) ]
       else:
           # SFTP file copy module is not really a module
           ftp = conn.open_sftp()
           ftp.put(self.module_args[0], self.module_args[1])
           ftp.close()
           conn.close()
           return [ host, True, 1 ]
           

   def _command(self, outpath):
       ''' form up a command string '''
       cmd = "%s %s" % (outpath, " ".join(self.module_args))
       return cmd

   def _exec_command(self, conn, cmd):
       ''' execute a command over SSH '''
       stdin, stdout, stderr = conn.exec_command(cmd)
       results = "\n".join(stdout.readlines())
       return results

   def _copy_module(self, conn):
       ''' transfer a module over SFTP '''
       in_path = os.path.expanduser(
           os.path.join(self.module_path, self.module_name)
       )
       out_path = os.path.join(
           "/var/spool/", 
           "ansible_%s" % self.module_name
       )
       sftp = conn.open_sftp()
       sftp.put(in_path, out_path)
       sftp.close()
       return out_path

   def run(self):
       ''' xfer & run module on all matched hosts '''
       hosts = [ h for h in self.host_list if self._matches(h) ]
       def executor(x):
           return self._executor(x)
       results = Pooler.parmap(executor, hosts)
       results2 = {
          "successful" : {},
          "failed"     : {}
       }
       for x in results:
           (host, is_ok, result) = x
           if not is_ok:
               results2["failed"][host] = result
           else:
               results2["successful"][host] = result
       return results2


if __name__ == '__main__':

    # test code...

    r = Runner(
       host_list = DEFAULT_HOST_LIST,
       module_name='ping',
       module_args='',
       pattern='*',
       forks=3
    )   
    print r.run()