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Commit b5b768df by Max Rothman
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Make mongo_rs_member manage whole cluster 

Now you can provide a (slightly simpler) cluster config and it'll
idempotently make it so.
parent c2c3922a
Showing with 194 additions and 192 deletions
playbooks/library/mongodb_rs_member
......@@ -3,11 +3,14 @@
DOCUMENTATION = """
---
module: mongo_rs_member
short_description: Modify replica set config for a member.
short_description: Modify replica set config.
description:
- Modify/Add/Remove members from a replica set. Member management as done by rs.reconfig().
- Modify replica set config, including modifing/adding/removing members from a replica set
and changing replica set options. Uses replSetReconfig and replSetInitiate.
version_added: "1.9"
author: Feanil Patel
author:
- Max Rothman
- Feanil Patel
options:
rs_host:
description:
......@@ -19,16 +22,6 @@ options:
- The port to connect to mongo on.
required: false
default: 27017
host:
description:
- The hostname of the member we want to modify.
required: false
default: 'localhost'
port:
description:
- The port of the member we want to modify.
required: false
default: 27017
username:
description:
- The username of the mongo user to connect as.
......@@ -41,36 +34,49 @@ options:
description:
- The database to authenticate against.
requred: false
priority:
description:
- The priority of the member in the replica set. Ignored if
`hidden` is set to true.
required: false
hidden:
description:
- Whether or not the member is hidden.
required: false
state:
description:
- Whether or not the member exists in the replica set. The member
will be added or removed to reach this state.
choices:
- present
- absent
default: present
force:
description: Whether to pass the "force" option to replSetReconfig.
For more details, see `<https://docs.mongodb.org/manual/reference/command/replSetReconfig/>`
required: false
default: false
rs_config:
description: A `replica set configuration document <https://docs.mongodb.org/manual/reference/replica-configuration/>`.
This structure can be a valid document, but this module can also manage some details for you:
- members can have separate ``host`` and ``port`` properties. ``port`` defaults to 27017.
To override this, provide a ``host`` like ``somehost:27017``.
- ``_id`` is automatically managed if not provided
- members' ``_id`` are automatically managed
- ``version`` is automatically incremented
required: true
"""
EXAMPLES = '''
- name: Get status for the stage cluster
- name: Basic example
mongo_rs_member:
rs_host: some.mongo
rs_port: 27017
host: localhost
port: 27017
username: root
password: password
register: mongo_config
rs_config:
members:
- host: some.host
- host: other.host
port: 27018
hidden: true
- name: Fully specify a whole document
mongo_rs_member:
username: admin
password: password
rs_config:
_id: myReplicaSetName
version: 5
members:
- _id: 1
host: some.host:27017
- _id: 2
host: other.host:27017
hidden: true
'''
# Magic import
from ansible.module_utils.basic import *
......@@ -84,38 +90,150 @@ except ImportError:
else:
pymongo_found = True
import json
import json, copy
from urllib import quote_plus
########### Mongo API calls ###########
def get_replset(client):
# Not using `replSetGetConfig` because it's not supported in MongoDB 2.x.
try:
rs_config = client.local.system.replset.find_one()
except OperationFailure as e:
module.fail_json(msg="Failed to retrieve existing replSet config: {}".format(e.message))
if rs_config is None or 'config' not in rs_config:
return None
else:
return rs_config['config']
def initialize_replset(rs_config):
try:
client.admin.command("replSetInitiate", rs_config)
except OperationFailure as e:
raise
module.fail_json(msg="Failed to initiate replSet: {}".format(e.message))
def reconfig_replset(rs_config):
try:
client.admin.command("replSetReconfig", rs_config, force=module.params['force'])
except OperationFailure as e:
raise
module.fail_json(msg="Failed to reconfigure replSet: {}".format(e.message))
def get_rs_config_id():
try:
replset_name = client.admin.command('getCmdLineOpts')['parsed']['replication']['replSetName']
except OperationFailure, KeyError as e:
module.fail_json(msg="Unable to get replSet name. Was mongod started with --replSet? Error: " + e.message)
########### Helper functions ###########
def set_member_ids(members, old_members=None):
'''
Set the _id property of members who don't already have one.
Prefer the _id of the "matching" member from `old_members`.
'''
available_ids = set(range(len(members)*2))
available_ids -= {m['_id'] for m in members}
if old_members is not None:
available_ids -= {m['_id'] for m in old_members}
available_ids = list(available_ids).sort(reverse=True)
for member in members:
if '_id' not in member:
if old_members is not None:
match = get_matching_member(member, old_members)
member['_id'] = match['_id'] if match is not None else available_ids.pop()
else:
member['_id'] = available_ids.pop()
return members
def get_matching_member(member, members):
'''Return the rs_member from `members` that "matches" `member`'''
match = [m for m in members if m['host'] == member['host']]
return match[0] if len(match) > 0 else None
def members_match(new, old):
"Compare 2 lists of members, discounting their `_id`s and matching on a custom criterion"
if len(new) != len(old):
return False
for old_member in old:
new_member = get_matching_member(old_member, new)
if old_member.copy().pop('_id') != new_member.copy().pop('_id'):
return False
return True
def fix_host_port(rs_config):
"Fix host, port to host:port"
if 'members' in rs_config:
if not isinstance(rs_config['members'], list)
module.fail_json(msg='rs_config.members must be a list')
for member in rs_config['members']:
if ':' not in member['host']:
member['host'] = '{}:{}'.format(member['host'], member.get('port', 27017))
del member['port']
def update_replset(rs_config):
changed = False
old_rs_config = get_replset(client)
fix_host_port(module, rs_config) #fix host, port to host:port
#Decide whether we need to initialize
if old_rs_config is None:
changed = True
if '_id' not in rs_config:
rs_config['_id'] = get_rs_config_id(client) #Errors if no replSet specified to mongod
rs_config['members'] = set_member_ids(rs_config['members']) #Noop if all _ids are set
#Don't set the version, it'll auto-set
initialize_replset(client, rs_config)
else:
rs_config_non_collections = {k:v for k,v in rs_config.items()
if not isinstance(v, list) if not isinstance(v, dict)}
old_rs_config_non_collections = {k:v for k,v in old_rs_config.items()
if not isinstance(v, list) if not isinstance(v, dict)}
# Is the provided doc "different" from the one currently on the cluster?
if rs_config_non_collections != old_rs_config_non_collections \
or rs_config['settings'] != old_rs_config['settings'] \
or not members_match(rs_config['members'], old_rs_config['members']):
changed=True
if '_id' not in rs_config:
rs_config['_id'] = get_rs_config_id(client) #Errors if no replSet specified to mongod
if 'version' not in rs_config:
#Using manual increment to prevent race condition
rs_config['version'] = old_rs_config['version'] + 1
#Noop if all _ids are set
rs_config['members'] = set_member_ids(rs_config['members'], old_rs_config['members'])
reconfig_replset(module, client, rs_config)
#Validate it worked
if changed:
changed_rs_config = get_replset(client)
if changed_rs_config != rs_config:
module.fail_json(msg="Failed to validate that the replica set was changed", config=rs_config)
module.exit_json(changed=changed, config=rs_config)
######### Client making stuff #########
def get_mongo_uri(host, port, username, password, auth_database):
mongo_uri = 'mongodb://'
if username and password:
mongo_uri += "{}:{}@".format(*map(quote_plus, [username,password]))
mongo_uri += "{}:{}".format(quote_plus(host),port)
mongo_uri += "{}:{}".format(quote_plus(host), port)
if auth_database:
mongo_uri += "/{}".format(quote_plus(auth_database))
return mongo_uri
def get_replset(module, client):
# Get the current config using `replSetGetConfig`
rs_config = client.admin.command("replSetGetConfig")
if 'config' not in rs_config:
module.fail_json(msg="Failed to get replset config from {}".format(primary_host), response=rs_config)
rs_config = rs_config['config']
return rs_config
def reconfig_replset(module, client, rs_config):
# Update the config version
try:
client.admin.command("replSetReconfig", rs_config)
except OperationFailure as e:
raise
module.fail_json(msg="Failed to reconfigure replSet: {}".format(e.message))
def primary_client(module, some_host, some_port, username, password, auth_database):
def primary_client(some_host, some_port, username, password, auth_database):
"""
Given a member of a replica set, find out who the primary is
and provide a client that is connected to the primary for running
......@@ -126,7 +244,7 @@ def primary_client(module, some_host, some_port, username, password, auth_databa
try:
status = client.admin.command("replSetGetStatus")
except OperationFailure as e:
module.fail_json(msg="Failed to get replica set status from host({}): {}".format(some_host, e.message))
module.fail_json(msg="Failed to get replica set status from host {}: {}".format(some_host, e.message))
# Find out who the primary is.
rs_primary = filter(lambda member: member['stateStr']=='PRIMARY', status['members'])[0]
......@@ -140,153 +258,37 @@ def primary_client(module, some_host, some_port, username, password, auth_databa
return client
def remove_member(module, client, rs_config):
host = module.params.get('host')
port = module.params.get('port')
existing_member_names = [ member['host'] for member in rs_config['members'] ]
dead_member_name = "{}:{}".format(host,port)
if dead_member_name in existing_member_names:
# Member is in config and needs to be removed.
new_member_list = filter(lambda member: member['host'] != dead_member_name, rs_config['members'])
rs_config['members'] = new_member_list
rs_config['version'] += 1
reconfig_replset(module, client, rs_config)
# Get status again.
status = client.admin.command("replSetGetConfig")['config']
# Validate that your instance is in there.
existing_member_names = [ member['host'] for member in rs_config['members'] ]
if dead_member_name not in existing_member_names:
module.exit_json(changed=True, config=rs_config)
else:
module.fail_json(msg="Failed to remove member from the replica set.", config=rs_config)
else:
# Member is not in the list.
module.exit_json(
changed=False,
msg="Member({}) was not in the replica set.".format(dead_member_name),
)
def upsert_member(module, client, rs_config):
rs_host = module.params.get('rs_host')
rs_port = module.params.get('rs_port')
host = module.params.get('host')
port = module.params.get('port')
username = module.params.get('username')
password = module.params.get('password')
priority = module.params.get('priority')
hidden = module.params.get('hidden')
state = module.params.get('state')
changed = False
# Ignore priority when member should be hidden.
# Hidden members have to be set to priority 0.
if hidden:
priority = 0
existing_member_names = [ member['host'] for member in rs_config['members'] ]
new_member_name = "{}:{}".format(host,port)
# See if member is already in the replica set
if new_member_name in existing_member_names:
# Make sure its config is the same. Grab a pointer to the current settings
# inside of the rs_config.
current_settings = filter(lambda member: member['host'] == new_member_name, rs_config['members'])[0]
need_to_update = False
# If the priority param is set and different from upstream.
if (priority is not None and current_settings['priority'] != priority):
current_settings['priority'] = priority
need_to_update = True
if current_settings['hidden'] != hidden:
current_settings['hidden'] = hidden
need_to_update = True
if need_to_update:
rs_config['version'] += 1
# This is a bit yucky since rs_config is updated because we update the dictionary
# that it references.
reconfig_replset(module, client, rs_config)
changed = True
else:
# Member exists and no settings need to be updated
module.exit_json(changed=False, config=rs_config)
else:
# New Member doesn't exist and we need to add it.
# First we build the config we need.
new_member_id = max([ member['_id'] for member in rs_config['members']]) + 1
new_member_config = { 'host': new_member_name , '_id': new_member_id }
if priority != None:
new_member_config['priority'] = priority
if hidden != None:
new_member_config['hidden'] = hidden
# Update the config.
rs_config['members'].append(new_member_config)
rs_config['version'] += 1
reconfig_replset(module, client, rs_config)
changed = True
# Get status again.
status = client.admin.command("replSetGetConfig")['config']
# Validate that your instance is in there.
existing_member_names = [ member['host'] for member in rs_config['members'] ]
if new_member_name in existing_member_names:
module.exit_json(changed=changed, config=rs_config)
else:
module.fail_json(msg="Failed to validate that the member we were modifying is in the replica set.", config=rs_config)
def main():
################ Main ################
def validate_args():
arg_spec = dict(
rs_host=dict(required=False, type='str', default="localhost"),
rs_port=dict(required=False, type='int', default=27017),
host=dict(required=False, type='str', default="localhost"),
port=dict(required=False, type='int', default=27017),
username=dict(required=False, type='str'),
password=dict(required=False, type='str'),
auth_database=dict(required=False, type='str'),
priority=dict(required=False, type='float'),
hidden=dict(required=False, type='bool', default=False),
state=dict(required=False, type="str", default="present"),
username = dict(required=False, type='str'),
password = dict(required=False, type='str'),
auth_database = dict(required=False, type='str'),
rs_host = dict(required=False, type='str', default="localhost"),
rs_port = dict(required=False, type='int', default=27017),
rs_config = dict(required=True, type='dict')
force = dict(required=False, type='bool', default=False),
)
module = AnsibleModule(argument_spec=arg_spec, supports_check_mode=False)
if (username and not password) or (password and not username):
module.fail_json(msg="Must provide both username and password or neither.")
return module
if __name__ == '__main__':
module = validate_args():
if not pymongo_found:
module.fail_json(msg="The python pymongo module is not installed.")
rs_host = module.params.get('rs_host')
rs_port = module.params.get('rs_port')
username = module.params.get('username')
password = module.params.get('password')
auth_database = module.params.get('auth_database')
state = module.params.get('state')
if (username and not password) or (password and not username):
module.fail_json(msg="Must provide both username and password or neither.")
rs_host = module.params['rs_host']
rs_port = module.params['rs_port']
client = primary_client(module, rs_host, rs_port, username, password, auth_database)
rs_config = get_replset(module, client)
if state == 'absent':
remove_member(module, client, rs_config)
elif state == 'present':
upsert_member(module, client, rs_config)
else:
module.fail_json(msg="Don't know about state: {}".format(state))
if __name__ == '__main__':
main()
update_replset(module, client, module['rs_config'])
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