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Genesis.

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mpdehaan committed Feb 23, 2012
0 parents commit f31421576b00f0b167cdbe61217c31c21a41ac02
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  1. +88 −0 README.md
  2. +165 −0 lib/ansible/__init__.py
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Ansible
=======
Ansible is a extra-simple Python API for doing 'remote things' over SSH.
As Func, which I co-wrote, aspired to avoid using SSH and have it's own daemon infrastructure, Ansible aspires to be quite different and more minimal, but still able to grow more modularly over time.
Principles
==========
* Dead simple setup
* No server or client daemons, uses existing SSHd
* Only SSH keys are allowed for authentication
* usage of ssh-agent is more or less required
* plugins can be written in ANY language
* as with Func, API usage is an equal citizen to CLI usage
Requirements
============
* python 2.6 -- or a backport of the multiprocessing module
* paramiko
Inventory file
==============
The default inventory file (-H) is ~/.ansible_hosts and is a list
of all hostnames to target with ansible, one per line.
This list is further filtered by the pattern wildcard (-P) to target
specific hosts.
Comamnd line usage example
==========================
Run a module by name with arguments
ansible -p "*.example.com" -m modName -a "arg1 arg2"
API Example
===========
The API is simple and returns basic datastructures.
import ansible
runner = ansible.Runner(command='inventory', host_list=['xyz.example.com', '...'])
data = runner.run()
{
'xyz.example.com' : [ 'any kind of datastructure is returnable' ],
'foo.example.com' : None, # failed to connect,
...
}
Additional options to runner include the number of forks, hostname
exclusion pattern, library path, and so on.
Parallelism
===========
Specify the number of forks to use, to run things in greater parallelism.
ansible -f 10 "*.example.com" -m modName -a "arg1 arg2"
Bundled Modules
===============
See the example library for modules, they can be written in any language
and simply return JSON to stdout. The path to your ansible library is
specified with the "-L" flag should you wish to use a different location
than "~/ansible".
Features not supported from Func (by design)
============================================
* Delegation for treeish topologies
* Asynchronous modes for long running tasks -- background tasks on your own
Future plans
============
* Dead-simple declarative configuration management & facts engine, with
probes implementable in any language.
Author
======
* Michael DeHaan <michael.dehaan@gmail.com> | http://michaeldehaan.net/
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# core
from optparse import OptionParser
import fnmatch
from multiprocessing import Process, Pipe
from itertools import izip
import os
import json
# non-core
import paramiko
DEFAULT_HOST_LIST = '~/.ansible_hosts'
DEFAULT_MODULE_PATH = '~/ansible'
DEFAULT_MODULE_NAME = 'ping'
DEFAULT_PATTERN = '*'
DEFAULT_FORKS = 3
DEFAULT_MODULE_ARGS = ''
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 Cli(object):
def __init__(self):
pass
def runner(self):
parser = OptionParser()
parser.add_option("-H", "--host-list", dest="host_list",
help="path to hosts list", default=DEFAULT_HOST_LIST)
parser.add_option("-L", "--library", dest="module_path",
help="path to module library", default=DEFAULT_MODULE_PATH)
parser.add_option("-F", "--forks", dest="forks",
help="level of parallelism", default=DEFAULT_FORKS)
parser.add_option("-n", "--name", dest="module_name",
help="module name to execute", default=DEFAULT_MODULE_NAME)
parser.add_option("-a", "--args", dest="module_args",
help="module arguments", default=DEFAULT_MODULE_ARGS)
parser.add_option("-p", "--pattern", dest="pattern",
help="hostname pattern", default=DEFAULT_PATTERN)
options, args = parser.parse_args()
host_list = self._host_list(options.host_list)
return Runner(
module_name=options.module_name,
module_path=options.module_path,
module_args=options.module_args,
host_list=host_list,
forks=options.forks,
pattern=options.pattern,
)
def _host_list(self, host_list):
host_list = os.path.expanduser(host_list)
return file(host_list).read().split("\n")
class Runner(object):
def __init__(self, host_list=[], module_path=None,
module_name=None, module_args='',
forks=3, timeout=60, pattern='*'):
self.host_list = 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
def _matches(self, host_name):
if host_name == '':
return False
if fnmatch.fnmatch(host_name, self.pattern):
return True
return False
def _connect(self, host):
ssh = paramiko.SSHClient()
ssh.set_missing_host_key_policy(paramiko.AutoAddPolicy())
try:
ssh.connect(host, username='root',
allow_agent=True, look_for_keys=True)
return ssh
except:
return None
def _executor(self, host):
# TODO: try/catch returning none
conn = self._connect(host)
if not conn:
return [ host, None ]
outpath = self._copy_module(conn)
self._exec_command(conn, "chmod +x %s" % outpath)
cmd = self._command(outpath)
result = self._exec_command(conn, cmd)
result = json.loads(result)
return [ host, result ]
def _command(self, outpath):
cmd = "%s %s" % (outpath, self.module_args)
return cmd
def _exec_command(self, conn, cmd):
stdin, stdout, stderr = conn.exec_command(cmd)
results = stdout.read()
return results
def _copy_module(self, conn):
inpath = os.path.expanduser(os.path.join(self.module_path, self.module_name))
outpath = os.path.join("/var/spool/", "ansible_%s" % self.module_name)
ftp = conn.open_sftp()
ftp.put(inpath, outpath)
ftp.close()
return outpath
def run(self):
hosts = [ h for h in self.host_list if self._matches(h) ]
def executor(x):
return self._executor(x)
results = Pooler.parmap(executor, hosts)
by_host = dict(results)
return by_host
if __name__ == '__main__':
# comamnd line usage example:
result = Cli().runner().run()
print json.dumps(result, sort_keys=True, indent=4)
# API usage example:
#r = Runner(
# host_list = [ '127.0.0.1' ],
# module_path='~/.ansible',
# module_name='ping',
# module_args='',
# pattern='*',
# forks=3
#)
#print r.run()

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