community.general/plugins/modules/consul_kv.py

335 lines
11 KiB
Python

#!/usr/bin/python
# -*- coding: utf-8 -*-
#
# Copyright (c) 2015, Steve Gargan <steve.gargan@gmail.com>
# Copyright (c) 2018 Genome Research Ltd.
# 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 = r"""
module: consul_kv
short_description: Manipulate entries in the key/value store of a Consul cluster
description:
- Allows the retrieval, addition, modification and deletion of key/value entries in a Consul cluster using the agent. The
entire contents of the record, including the indices, flags and session are returned as C(value).
- If the O(key) represents a prefix then note that when a value is removed, the existing value if any is returned as part
of the results.
- See http://www.consul.io/docs/agent/http.html#kv for more details.
requirements:
- python-consul
- requests
author:
- Steve Gargan (@sgargan)
- Colin Nolan (@colin-nolan)
extends_documentation_fragment:
- community.general.attributes
attributes:
check_mode:
support: full
diff_mode:
support: none
options:
state:
description:
- The action to take with the supplied key and value. If the state is V(present) and O(value) is set, the key contents
will be set to the value supplied and C(changed) will be set to V(true) only if the value was different to the current
contents. If the state is V(present) and O(value) is not set, the existing value associated to the key will be returned.
The state V(absent) will remove the key/value pair, again C(changed) will be set to V(true) only if the key actually
existed prior to the removal. An attempt can be made to obtain or free the lock associated with a key/value pair with
the states V(acquire) or V(release) respectively. A valid session must be supplied to make the attempt C(changed)
will be V(true) if the attempt is successful, V(false) otherwise.
type: str
choices: [absent, acquire, present, release]
default: present
key:
description:
- The key at which the value should be stored.
type: str
required: true
value:
description:
- The value should be associated with the given key, required if O(state) is V(present).
type: str
recurse:
description:
- If the key represents a prefix, each entry with the prefix can be retrieved by setting this to V(true).
type: bool
retrieve:
description:
- If the O(state) is V(present) and O(value) is set, perform a read after setting the value and return this value.
default: true
type: bool
session:
description:
- The session that should be used to acquire or release a lock associated with a key/value pair.
type: str
token:
description:
- The token key identifying an ACL rule set that controls access to the key value pair.
type: str
cas:
description:
- Used when acquiring a lock with a session. If the O(cas) is V(0), then Consul will only put the key if it does not
already exist. If the O(cas) value is non-zero, then the key is only set if the index matches the ModifyIndex of that
key.
type: str
flags:
description:
- Opaque positive integer value that can be passed when setting a value.
type: str
host:
description:
- Host of the Consul agent.
type: str
default: localhost
port:
description:
- The port on which the Consul agent is running.
type: int
default: 8500
scheme:
description:
- The protocol scheme on which the Consul agent is running.
type: str
default: http
validate_certs:
description:
- Whether to verify the tls certificate of the Consul agent.
type: bool
default: true
datacenter:
description:
- The name of the datacenter to query. If unspecified, the query will default to the datacenter of the Consul agent
on O(host).
type: str
version_added: 10.0.0
"""
EXAMPLES = r"""
# If the key does not exist, the value associated to the "data" property in `retrieved_key` will be `None`
# If the key value is empty string, `retrieved_key["data"]["Value"]` will be `None`
- name: Retrieve a value from the key/value store
community.general.consul_kv:
key: somekey
register: retrieved_key
- name: Add or update the value associated with a key in the key/value store
community.general.consul_kv:
key: somekey
value: somevalue
- name: Remove a key from the store
community.general.consul_kv:
key: somekey
state: absent
- name: Add a node to an arbitrary group using Consul inventory (see consul.ini)
community.general.consul_kv:
key: ansible/groups/dc1/somenode
value: top_secret
- name: Register a key/value pair with an associated session
community.general.consul_kv:
key: stg/node/server_birthday
value: 20160509
session: "{{ sessionid }}"
state: acquire
"""
from ansible.module_utils.common.text.converters import to_text
try:
import consul
from requests.exceptions import ConnectionError
python_consul_installed = True
except ImportError:
python_consul_installed = False
from ansible.module_utils.basic import AnsibleModule
# Note: although the python-consul documentation implies that using a key with a value of `None` with `put` has a
# special meaning (https://python-consul.readthedocs.io/en/latest/#consul-kv), if not set in the subsequently API call,
# the value just defaults to an empty string (https://www.consul.io/api/kv.html#create-update-key)
NOT_SET = None
def _has_value_changed(consul_client, key, target_value):
"""
Uses the given Consul client to determine if the value associated to the given key is different to the given target
value.
:param consul_client: Consul connected client
:param key: key in Consul
:param target_value: value to be associated to the key
:return: tuple where the first element is the value of the "X-Consul-Index" header and the second is `True` if the
value has changed (i.e. the stored value is not the target value)
"""
index, existing = consul_client.kv.get(key)
if not existing:
return index, True
try:
changed = to_text(existing['Value'], errors='surrogate_or_strict') != target_value
return index, changed
except UnicodeError:
# Existing value was not decodable but all values we set are valid utf-8
return index, True
def execute(module):
state = module.params.get('state')
if state == 'acquire' or state == 'release':
lock(module, state)
elif state == 'present':
if module.params.get('value') is NOT_SET:
get_value(module)
else:
set_value(module)
elif state == 'absent':
remove_value(module)
else:
module.exit_json(msg="Unsupported state: %s" % (state, ))
def lock(module, state):
consul_api = get_consul_api(module)
session = module.params.get('session')
key = module.params.get('key')
value = module.params.get('value')
if not session:
module.fail(
msg='%s of lock for %s requested but no session supplied' %
(state, key))
index, changed = _has_value_changed(consul_api, key, value)
if changed and not module.check_mode:
if state == 'acquire':
changed = consul_api.kv.put(key, value,
cas=module.params.get('cas'),
acquire=session,
flags=module.params.get('flags'))
else:
changed = consul_api.kv.put(key, value,
cas=module.params.get('cas'),
release=session,
flags=module.params.get('flags'))
module.exit_json(changed=changed,
index=index,
key=key)
def get_value(module):
consul_api = get_consul_api(module)
key = module.params.get('key')
index, existing_value = consul_api.kv.get(key, recurse=module.params.get('recurse'))
module.exit_json(changed=False, index=index, data=existing_value)
def set_value(module):
consul_api = get_consul_api(module)
key = module.params.get('key')
value = module.params.get('value')
if value is NOT_SET:
raise AssertionError('Cannot set value of "%s" to `NOT_SET`' % key)
index, changed = _has_value_changed(consul_api, key, value)
if changed and not module.check_mode:
changed = consul_api.kv.put(key, value,
cas=module.params.get('cas'),
flags=module.params.get('flags'))
stored = None
if module.params.get('retrieve'):
index, stored = consul_api.kv.get(key)
module.exit_json(changed=changed,
index=index,
key=key,
data=stored)
def remove_value(module):
''' remove the value associated with the given key. if the recurse parameter
is set then any key prefixed with the given key will be removed. '''
consul_api = get_consul_api(module)
key = module.params.get('key')
index, existing = consul_api.kv.get(
key, recurse=module.params.get('recurse'))
changed = existing is not None
if changed and not module.check_mode:
consul_api.kv.delete(key, module.params.get('recurse'))
module.exit_json(changed=changed,
index=index,
key=key,
data=existing)
def get_consul_api(module):
return consul.Consul(host=module.params.get('host'),
port=module.params.get('port'),
scheme=module.params.get('scheme'),
verify=module.params.get('validate_certs'),
token=module.params.get('token'),
dc=module.params.get('datacenter'))
def test_dependencies(module):
if not python_consul_installed:
module.fail_json(msg="python-consul required for this module. "
"see https://python-consul.readthedocs.io/en/latest/#installation")
def main():
module = AnsibleModule(
argument_spec=dict(
cas=dict(type='str'),
datacenter=dict(type='str', default=None),
flags=dict(type='str'),
key=dict(type='str', required=True, no_log=False),
host=dict(type='str', default='localhost'),
scheme=dict(type='str', default='http'),
validate_certs=dict(type='bool', default=True),
port=dict(type='int', default=8500),
recurse=dict(type='bool'),
retrieve=dict(type='bool', default=True),
state=dict(type='str', default='present', choices=['absent', 'acquire', 'present', 'release']),
token=dict(type='str', no_log=True),
value=dict(type='str', default=NOT_SET),
session=dict(type='str'),
),
supports_check_mode=True
)
test_dependencies(module)
try:
execute(module)
except ConnectionError as e:
module.fail_json(msg='Could not connect to consul agent at %s:%s, error was %s' % (
module.params.get('host'), module.params.get('port'), e))
except Exception as e:
module.fail_json(msg=str(e))
if __name__ == '__main__':
main()