ansible/library/utilities/wait_for

#!/usr/bin/python
# -*- coding: utf-8 -*-

# (c) 2012, Jeroen Hoekx <jeroen@hoekx.be>
#
# 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/>.

import socket
import datetime
import time
import sys
import re

DOCUMENTATION = '''
---
module: wait_for
short_description: Waits for a condition before continuing.
description:
     - Waiting for a port to become available is useful for when services 
       are not immediately available after their init scripts return - 
       which is true of certain Java application servers. It is also 
       useful when starting guests with the M(virt) module and
       needing to pause until they are ready. 
     - This module can also be used to wait for a regex match a string to be present in a file.
     - In 1.6 and later, this module can 
       also be used to wait for a file to be available or absent on the 
       filesystem.
version_added: "0.7"
options:
  host:
    description:
      - hostname or IP address to wait for
    required: false
    default: "127.0.0.1"
    aliases: []
  timeout:
    description:
      - maximum number of seconds to wait for
    required: false
    default: 300
  delay:
    description:
      - number of seconds to wait before starting to poll
    required: false
    default: 0
  port:
    description:
      - port number to poll
    required: false
  state:
    description:
      - either C(present), C(started), or C(stopped), C(absent)
      - When checking a port C(started) will ensure the port is open, C(stopped) will check that it is closed
      - When checking for a file or a search string C(present) or C(started) will ensure that the file or string is present before continuing, C(absent) will check that file is absent or removed
    choices: [ "present", "started", "stopped", "absent" ]
    default: "started"
  path:
    version_added: "1.4"
    required: false
    description:
      - path to a file on the filesytem that must exist before continuing
  search_regex:
    version_added: "1.4"
    required: false
    description:
      - with the path option can be used match a string in the file that must match before continuing.  Defaults to a multiline regex.
   
notes: []
requirements: []
author: Jeroen Hoekx, John Jarvis, Andrii Radyk
'''

EXAMPLES = '''

# wait 300 seconds for port 8000 to become open on the host, don't start checking for 10 seconds
- wait_for: port=8000 delay=10

# wait until the file /tmp/foo is present before continuing
- wait_for: path=/tmp/foo

# wait until the string "completed" is in the file /tmp/foo before continuing
- wait_for: path=/tmp/foo search_regex=completed

# wait until the lock file is removed
- wait_for: path=/var/lock/file.lock state=absent 

# wait until the process is finished and pid was destroyed
- wait_for: path=/proc/3466/status state=absent

'''

def main():

    module = AnsibleModule(
        argument_spec = dict(
            host=dict(default='127.0.0.1'),
            timeout=dict(default=300),
            connect_timeout=dict(default=5),
            delay=dict(default=0),
            port=dict(default=None),
            path=dict(default=None),
            search_regex=dict(default=None),
            state=dict(default='started', choices=['started', 'stopped', 'present', 'absent']),
        ),
    )

    params = module.params

    host = params['host']
    timeout = int(params['timeout'])
    connect_timeout = int(params['connect_timeout'])
    delay = int(params['delay'])
    if params['port']:
        port = int(params['port'])
    else:
        port = None
    state = params['state']
    path = params['path']
    search_regex = params['search_regex']
    
    if port and path:
        module.fail_json(msg="port and path parameter can not both be passed to wait_for")
    if path and state == 'stopped':
        module.fail_json(msg="state=stopped should only be used for checking a port in the wait_for module")
        
    start = datetime.datetime.now()

    if delay:
        time.sleep(delay)

    if state in [ 'stopped', 'absent' ]:
        ### first wait for the stop condition
        end = start + datetime.timedelta(seconds=timeout)

        while datetime.datetime.now() < end:
            if path:
                try:
                    f = open(path)
                    f.close()
                    time.sleep(1)
                    pass
                except IOError:
                    break
            elif port:
                s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
                s.settimeout(connect_timeout)
                try:
                    s.connect( (host, port) )
                    s.shutdown(socket.SHUT_RDWR)
                    s.close()
                    time.sleep(1)
                except:
                    break
        else:
            elapsed = datetime.datetime.now() - start
            if port:
                module.fail_json(msg="Timeout when waiting for %s:%s to stop." % (host, port), elapsed=elapsed.seconds)
            elif path:
                module.fail_json(msg="Timeout when waiting for %s to be absent." % (path), elapsed=elapsed.seconds)

    elif state in ['started', 'present']:
        ### wait for start condition
        end = start + datetime.timedelta(seconds=timeout)
        while datetime.datetime.now() < end:
            if path:
                try:
                    f = open(path)
                    try:
                        if search_regex:
                            if re.search(search_regex, f.read(), re.MULTILINE):
                                break
                            else:
                                time.sleep(1)
                        else:
                            break
                    finally:
                        f.close()
                except IOError:
                    time.sleep(1)
                    pass
            elif port:
                s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
                s.settimeout(connect_timeout)
                try:
                    s.connect( (host, port) )
                    s.shutdown(socket.SHUT_RDWR)
                    s.close()
                    break
                except:
                    time.sleep(1)
                    pass
        else:
            elapsed = datetime.datetime.now() - start
            if port:
                module.fail_json(msg="Timeout when waiting for %s:%s" % (host, port), elapsed=elapsed.seconds)
            elif path:
                if search_regex:
                    module.fail_json(msg="Timeout when waiting for search string %s in %s" % (search_regex, path), elapsed=elapsed.seconds)
                else:
                    module.fail_json(msg="Timeout when waiting for file %s" % (path), elapsed=elapsed.seconds)


    elapsed = datetime.datetime.now() - start
    module.exit_json(state=state, port=port, search_regex=search_regex, path=path, elapsed=elapsed.seconds)

# import module snippets
from ansible.module_utils.basic import *
main()