#!/usr/bin/python
# -*- coding: utf-8 -*-
# Copyright (c) 2016, Olivier Boukili <boukili.olivier@gmail.com>
# GNU General Public License v3.0+ (see LICENSES/GPL-3.0-or-later.txt or https://www.gnu.org/licenses/gpl-3.0.txt)
# SPDX-License-Identifier: GPL-3.0-or-later
from __future__ import absolute_import, division, print_function
__metaclass__ = type
DOCUMENTATION = '''
---
module: apache2_mod_proxy
author: Olivier Boukili (@oboukili)
short_description: Set and/or get members' attributes of an Apache httpd 2.4 mod_proxy balancer pool
description:
- Set and/or get members' attributes of an Apache httpd 2.4 mod_proxy balancer
pool, using HTTP POST and GET requests. The httpd mod_proxy balancer-member
status page has to be enabled and accessible, as this module relies on parsing
this page. This module supports ansible check_mode, and requires BeautifulSoup
python module.
extends_documentation_fragment:
- community.general.attributes
attributes:
check_mode:
support: full
diff_mode:
support: none
options:
balancer_url_suffix:
type: str
description:
- Suffix of the balancer pool url required to access the balancer pool
status page (e.g. balancer_vhost[:port]/balancer_url_suffix).
default: /balancer-manager/
balancer_vhost:
type: str
description:
- (ipv4|ipv6|fqdn):port of the Apache httpd 2.4 mod_proxy balancer pool.
required: true
member_host:
type: str
description:
- (ipv4|ipv6|fqdn) of the balancer member to get or to set attributes to.
Port number is autodetected and should not be specified here.
If undefined, apache2_mod_proxy module will return a members list of
dictionaries of all the current balancer pool members' attributes.
state:
type: str
description:
- Desired state of the member host.
(absent|disabled),drained,hot_standby,ignore_errors can be
simultaneously invoked by separating them with a comma (e.g. state=drained,ignore_errors).
- 'Accepted state values: ["present", "absent", "enabled", "disabled", "drained", "hot_standby", "ignore_errors"]'
tls:
description:
- Use https to access balancer management page.
type: bool
default: false
validate_certs:
description:
- Validate ssl/tls certificates.
type: bool
default: true
'''
EXAMPLES = '''
- name: Get all current balancer pool members attributes
community.general.apache2_mod_proxy:
balancer_vhost: 10.0.0.2
- name: Get a specific member attributes
community.general.apache2_mod_proxy:
balancer_vhost: myws.mydomain.org
balancer_suffix: /lb/
member_host: node1.myws.mydomain.org
# Enable all balancer pool members:
- name: Get attributes
community.general.apache2_mod_proxy:
balancer_vhost: '{{ myloadbalancer_host }}'
register: result
- name: Enable all balancer pool members
community.general.apache2_mod_proxy:
balancer_vhost: '{{ myloadbalancer_host }}'
member_host: '{{ item.host }}'
state: present
with_items: '{{ result.members }}'
# Gracefully disable a member from a loadbalancer node:
- name: Step 1
community.general.apache2_mod_proxy:
balancer_vhost: '{{ vhost_host }}'
member_host: '{{ member.host }}'
state: drained
delegate_to: myloadbalancernode
- name: Step 2
ansible.builtin.wait_for:
host: '{{ member.host }}'
port: '{{ member.port }}'
state: drained
delegate_to: myloadbalancernode
- name: Step 3
community.general.apache2_mod_proxy:
balancer_vhost: '{{ vhost_host }}'
member_host: '{{ member.host }}'
state: absent
delegate_to: myloadbalancernode
'''
RETURN = '''
member:
description: specific balancer member information dictionary, returned when apache2_mod_proxy module is invoked with member_host parameter.
type: dict
returned: success
sample:
{"attributes":
{"Busy": "0",
"Elected": "42",
"Factor": "1",
"From": "136K",
"Load": "0",
"Route": null,
"RouteRedir": null,
"Set": "0",
"Status": "Init Ok ",
"To": " 47K",
"Worker URL": null
},
"balancer_url": "http://10.10.0.2/balancer-manager/",
"host": "10.10.0.20",
"management_url": "http://10.10.0.2/lb/?b=mywsbalancer&w=http://10.10.0.20:8080/ws&nonce=8925436c-79c6-4841-8936-e7d13b79239b",
"path": "/ws",
"port": 8080,
"protocol": "http",
"status": {
"disabled": false,
"drained": false,
"hot_standby": false,
"ignore_errors": false
}
}
members:
description: list of member (defined above) dictionaries, returned when apache2_mod_proxy is invoked with no member_host and state args.
returned: success
type: list
sample:
[{"attributes": {
"Busy": "0",
"Elected": "42",
"Factor": "1",
"From": "136K",
"Load": "0",
"Route": null,
"RouteRedir": null,
"Set": "0",
"Status": "Init Ok ",
"To": " 47K",
"Worker URL": null
},
"balancer_url": "http://10.10.0.2/balancer-manager/",
"host": "10.10.0.20",
"management_url": "http://10.10.0.2/lb/?b=mywsbalancer&w=http://10.10.0.20:8080/ws&nonce=8925436c-79c6-4841-8936-e7d13b79239b",
"path": "/ws",
"port": 8080,
"protocol": "http",
"status": {
"disabled": false,
"drained": false,
"hot_standby": false,
"ignore_errors": false
}
},
{"attributes": {
"Busy": "0",
"Elected": "42",
"Factor": "1",
"From": "136K",
"Load": "0",
"Route": null,
"RouteRedir": null,
"Set": "0",
"Status": "Init Ok ",
"To": " 47K",
"Worker URL": null
},
"balancer_url": "http://10.10.0.2/balancer-manager/",
"host": "10.10.0.21",
"management_url": "http://10.10.0.2/lb/?b=mywsbalancer&w=http://10.10.0.21:8080/ws&nonce=8925436c-79c6-4841-8936-e7d13b79239b",
"path": "/ws",
"port": 8080,
"protocol": "http",
"status": {
"disabled": false,
"drained": false,
"hot_standby": false,
"ignore_errors": false}
}
]
'''
import re
import traceback
from ansible.module_utils.basic import AnsibleModule, missing_required_lib
from ansible.module_utils.urls import fetch_url
from ansible.module_utils.six import iteritems
BEAUTIFUL_SOUP_IMP_ERR = None
try:
from BeautifulSoup import BeautifulSoup
except ImportError:
BEAUTIFUL_SOUP_IMP_ERR = traceback.format_exc()
HAS_BEAUTIFULSOUP = False
else:
HAS_BEAUTIFULSOUP = True
# balancer member attributes extraction regexp:
EXPRESSION = r"(b=([\w\.\-]+)&w=(https?|ajp|wss?|ftp|[sf]cgi)://([\w\.\-]+):?(\d*)([/\w\.\-]*)&?[\w\-\=]*)"
# Apache2 server version extraction regexp:
APACHE_VERSION_EXPRESSION = r"SERVER VERSION: APACHE/([\d.]+)"
def regexp_extraction(string, _regexp, groups=1):
""" Returns the capture group (default=1) specified in the regexp, applied to the string """
regexp_search = re.search(string=str(string), pattern=str(_regexp))
if regexp_search:
if regexp_search.group(groups) != '':
return str(regexp_search.group(groups))
return None
class BalancerMember(object):
""" Apache 2.4 mod_proxy LB balancer member.
attributes:
read-only:
host -> member host (string),
management_url -> member management url (string),
protocol -> member protocol (string)
port -> member port (string),
path -> member location (string),
balancer_url -> url of this member's parent balancer (string),
attributes -> whole member attributes (dictionary)
module -> ansible module instance (AnsibleModule object).
writable:
status -> status of the member (dictionary)
"""
def __init__(self, management_url, balancer_url, module):
self.host = regexp_extraction(management_url, str(EXPRESSION), 4)
self.management_url = str(management_url)
self.protocol = regexp_extraction(management_url, EXPRESSION, 3)
self.port = regexp_extraction(management_url, EXPRESSION, 5)
self.path = regexp_extraction(management_url, EXPRESSION, 6)
self.balancer_url = str(balancer_url)
self.module = module
def get_member_attributes(self):
""" Returns a dictionary of a balancer member's attributes."""
balancer_member_page = fetch_url(self.module, self.management_url)
if balancer_member_page[1]['status'] != 200:
self.module.fail_json(msg="Could not get balancer_member_page, check for connectivity! " + balancer_member_page[1])
else:
try:
soup = BeautifulSoup(balancer_member_page[0])
except TypeError as exc:
self.module.fail_json(msg="Cannot parse balancer_member_page HTML! " + str(exc))
else:
subsoup = soup.findAll('table')[1].findAll('tr')
keys = subsoup[0].findAll('th')
for valuesset in subsoup[1::1]:
if re.search(pattern=self.host, string=str(valuesset)):
values = valuesset.findAll('td')
return dict((keys[x].string, values[x].string) for x in range(0, len(keys)))
def get_member_status(self):
""" Returns a dictionary of a balancer member's status attributes."""
status_mapping = {'disabled': 'Dis',
'drained': 'Drn',
'hot_standby': 'Stby',
'ignore_errors': 'Ign'}
actual_status = str(self.attributes['Status'])
status = dict((mode, patt in actual_status) for mode, patt in iteritems(status_mapping))
return status
def set_member_status(self, values):
""" Sets a balancer member's status attributes amongst pre-mapped values."""
values_mapping = {'disabled': '&w_status_D',
'drained': '&w_status_N',
'hot_standby': '&w_status_H',
'ignore_errors': '&w_status_I'}
request_body = regexp_extraction(self.management_url, EXPRESSION, 1)
values_url = "".join("{0}={1}".format(url_param, 1 if values[mode] else 0) for mode, url_param in iteritems(values_mapping))
request_body = "{0}{1}".format(request_body, values_url)
response = fetch_url(self.module, self.management_url, data=request_body)
if response[1]['status'] != 200:
self.module.fail_json(msg="Could not set the member status! " + self.host + " " + response[1]['status'])
attributes = property(get_member_attributes)
status = property(get_member_status, set_member_status)
class Balancer(object):
""" Apache httpd 2.4 mod_proxy balancer object"""
def __init__(self, host, suffix, module, members=None, tls=False):
if tls:
self.base_url = 'https://' + str(host)
self.url = 'https://' + str(host) + str(suffix)
else:
self.base_url = 'http://' + str(host)
self.url = 'http://' + str(host) + str(suffix)
self.module = module
self.page = self.fetch_balancer_page()
if members is None:
self._members = []
def fetch_balancer_page(self):
""" Returns the balancer management html page as a string for later parsing."""
page = fetch_url(self.module, str(self.url))
if page[1]['status'] != 200:
self.module.fail_json(msg="Could not get balancer page! HTTP status response: " + str(page[1]['status']))
else:
content = page[0].read()
apache_version = regexp_extraction(content.upper(), APACHE_VERSION_EXPRESSION, 1)
if apache_version:
if not re.search(pattern=r"2\.4\.[\d]*", string=apache_version):
self.module.fail_json(msg="This module only acts on an Apache2 2.4+ instance, current Apache2 version: " + str(apache_version))
return content
else:
self.module.fail_json(msg="Could not get the Apache server version from the balancer-manager")
def get_balancer_members(self):
""" Returns members of the balancer as a generator object for later iteration."""
try:
soup = BeautifulSoup(self.page)
except TypeError:
self.module.fail_json(msg="Cannot parse balancer page HTML! " + str(self.page))
else:
for element in soup.findAll('a')[1::1]:
balancer_member_suffix = str(element.get('href'))
if not balancer_member_suffix:
self.module.fail_json(msg="Argument 'balancer_member_suffix' is empty!")
else:
yield BalancerMember(str(self.base_url + balancer_member_suffix), str(self.url), self.module)
members = property(get_balancer_members)
def main():
""" Initiates module."""
module = AnsibleModule(
argument_spec=dict(
balancer_vhost=dict(required=True, type='str'),
balancer_url_suffix=dict(default="/balancer-manager/", type='str'),
member_host=dict(type='str'),
state=dict(type='str'),
tls=dict(default=False, type='bool'),
validate_certs=dict(default=True, type='bool')
),
supports_check_mode=True
)
if HAS_BEAUTIFULSOUP is False:
module.fail_json(msg=missing_required_lib('BeautifulSoup'), exception=BEAUTIFUL_SOUP_IMP_ERR)
if module.params['state'] is not None:
states = module.params['state'].split(',')
if (len(states) > 1) and (("present" in states) or ("enabled" in states)):
module.fail_json(msg="state present/enabled is mutually exclusive with other states!")
else:
for _state in states:
if _state not in ['present', 'absent', 'enabled', 'disabled', 'drained', 'hot_standby', 'ignore_errors']:
module.fail_json(
msg="State can only take values amongst 'present', 'absent', 'enabled', 'disabled', 'drained', 'hot_standby', 'ignore_errors'."
)
else:
states = ['None']
mybalancer = Balancer(module.params['balancer_vhost'],
module.params['balancer_url_suffix'],
module=module,
tls=module.params['tls'])
if module.params['member_host'] is None:
json_output_list = []
for member in mybalancer.members:
json_output_list.append({
"host": member.host,
"status": member.status,
"protocol": member.protocol,
"port": member.port,
"path": member.path,
"attributes": member.attributes,
"management_url": member.management_url,
"balancer_url": member.balancer_url
})
module.exit_json(
changed=False,
members=json_output_list
)
else:
changed = False
member_exists = False
member_status = {'disabled': False, 'drained': False, 'hot_standby': False, 'ignore_errors': False}
for mode in member_status.keys():
for state in states:
if mode == state:
member_status[mode] = True
elif mode == 'disabled' and state == 'absent':
member_status[mode] = True
for member in mybalancer.members:
if str(member.host) == str(module.params['member_host']):
member_exists = True
if module.params['state'] is not None:
member_status_before = member.status
if not module.check_mode:
member_status_after = member.status = member_status
else:
member_status_after = member_status
if member_status_before != member_status_after:
changed = True
json_output = {
"host": member.host,
"status": member.status,
"protocol": member.protocol,
"port": member.port,
"path": member.path,
"attributes": member.attributes,
"management_url": member.management_url,
"balancer_url": member.balancer_url
}
if member_exists:
module.exit_json(
changed=changed,
member=json_output
)
else:
module.fail_json(msg=str(module.params['member_host']) + ' is not a member of the balancer ' + str(module.params['balancer_vhost']) + '!')
if __name__ == '__main__':
main()