ansible/library/service

#!/usr/bin/python

# (c) 2012, Michael DeHaan <michael.dehaan@gmail.com>
#
# This file is part of Ansible
#
# Ansible is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# Ansible is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with Ansible.  If not, see <http://www.gnu.org/licenses/>.

try:
    import json
except ImportError:
    import simplejson as json
import sys
import shlex
import subprocess

# TODO: switch to fail_json and other helper functions
# like other modules are using

# ===========================================

SERVICE = '/sbin/service'
CHKCONFIG = '/sbin/chkconfig'

def _run(cmd):
    # returns (rc, stdout, stderr) from shell command
    process = subprocess.Popen(cmd, stdout=subprocess.PIPE, stderr=subprocess.PIPE, shell=True)
    stdout, stderr = process.communicate()
    return (process.returncode, stdout, stderr) 


def _do_enable(name, enable):
    if enable.lower() in ['on', 'true', 'yes']:
        rc, stdout, stderr = _run("%s %s on" % (CHKCONFIG, name))
    elif enable.lower() in ['off', 'false', 'no']:
        rc, stdout, stderr = _run("%s %s off" % (CHKCONFIG, name))
    
    return rc, stdout, stderr
    
argfile = sys.argv[1]
args = open(argfile, 'r').read()
items = shlex.split(args)

if not len(items):
    print json.dumps(dict(failed=True, msg='this module requires arguments (-a)'))
    sys.exit(1)

params = {}
for arg in items:
    if "=" not in arg:
        print json.dumps(dict(failed=True, msg='expected key=value format arguments'))
        sys.exit(1)
    (name, value) = arg.split("=")
    params[name] = value

name = params.get('name', None)

if name is None:
    print json.dumps(dict(failed=True, msg='missing name'))
    sys.exit(1)

state = params.get('state', None)
list_items = params.get('list', None)
enable = params.get('enable', None)

# running and started are the same
if state and state not in [ 'running', 'started', 'stopped', 'restarted' ]:
    print json.dumps(dict(failed=True, msg='invalid value for state'))
    sys.exit(1)
if list_items and list_items not in [ 'status' ]:
    print json.dumps(dict(failed=True, msg='invalid value for list'))
    sys.exit(1)
if enable and enable.lower() not in [ 'on', 'off', 'true', 'false', 'yes', 'no' ]:
    print json.dumps(dict(failed=True, msg='invalid value for enable'))
    sys.exit(1)


# ===========================================
# get service status

rc, status_stdout, status_stderr = _run("%s %s status" % (SERVICE, name))
status = status_stdout + status_stderr


running = False
if status_stdout.find("not running") != -1:
    running = False
elif status_stdout.find("running") != -1:
    running = True
elif name == 'iptables' and status_stdout.find("ACCEPT") != -1:
    # iptables status command output is lame
    # TODO: lookup if we can use a return code for this instead?
    running = True

if state or enable:
    rc = 0
    out = ''
    err = ''
    changed = False
        
    if enable:
        rc_enable, out_enable, err_enable = _do_enable(name, enable)
        rc += rc_enable
        out += out_enable
        err += err_enable

    if state:
        # a state change command has been requested

        # ===========================================
        # determine if we are going to change anything

        if not running and state == "started":
            changed = True
        elif running and state == "stopped":
            changed = True
        elif state == "restarted":
            changed = True

        # ===========================================
        # run change commands if we need to

        if changed:
            if state in ('started', 'running'):
                rc_state, stdout, stderr = _run("%s %s start" % (SERVICE, name))
            elif state == 'stopped':
                rc_state, stdout, stderr = _run("%s %s stop" % (SERVICE, name))
            elif state == 'restarted':
                rc1, stdout1, stderr1 = _run("%s %s stop" % (SERVICE, name))
                rc2, stdout2, stderr2 = _run("%s %s start" % (SERVICE, name))
                rc_state = rc and rc1 and rc2
                stdout = stdout1 + stdout2
                stderr = stderr1 + stderr2
            
            out += stdout
            err += stderr
            rc = rc and rc_state
        
    if rc != 0:

        print json.dumps({
            "failed" : 1,
            "rc"     : rc,
        })
        print >> sys.stderr, out + err
        sys.exit(1)


    # ===============================================
    # success

    result = {"changed": changed}

    rc, stdout, stderr = _run("%s %s status" % (SERVICE, name))
    if list_items and list_items in [ 'status' ]:
        result['status'] = stdout
    print json.dumps(result)

    
elif list_items is not None:

    # solo list=status mode, don't change anything, just return
    # suitable for /usr/bin/ansible usage or API, playbooks
    # not so much

    print json.dumps({
        "status" : status
    })

else:
 
    print json.dumps(dict(failed=True, msg="expected state or list parameters"))    


sys.exit(0)